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"troposphere" Definitions
  1. the lowest layer of the atmosphere, 6 miles (10 km) high in some areas and as much as 12 miles (20 km) high in others, within which there is a steady drop in temperature with increasing altitude and within which nearly all cloud formations occur and weather conditions manifest themselves.
"troposphere" Synonyms
aerospace atmosphere exosphere mesosphere space stratosphere thermosphere upper atmosphere sky heavens blue firmament aerosphere air ether airspace ozone welkin heaven vault of heaven
"troposphere" Antonyms
hell

681 Sentences With "troposphere"

How to use troposphere in a sentence? Find typical usage patterns (collocations)/phrases/context for "troposphere" and check conjugation/comparative form for "troposphere". Mastering all the usages of "troposphere" from sentence examples published by news publications.

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Lofted into the troposphere, that water vapor would rain out fairly quickly.
He seemed relaxed for a man about to fall through a mile or so of troposphere.
Our modern atmosphere is divided into the troposphere, where we live, then the stratosphere, mesosphere and thermosphere.
Additionally, the measured temperatures in the troposphere are consistent with models that suggest a strengthening seasonal heartbeat.
The colder the cloud tops, the higher they are in the troposphere and the stronger the storms.
Such events occur when large atmospheric waves surge beyond the troposphere and into the layer of air above it.
That substance would then get pumped through the troposphere (the lowest layer of Earth's atmosphere) and into the stratosphere.
After all, lots of others are out there warming the troposphere: power plants, trucking, the military, you name it.
The vortex exists in the stratosphere (around 10-plus miles up), well above the troposphere where we experience our weather.
Any anxiety you might feel that Cardi B might somehow disappear from the pop music troposphere should by now be alleviated.
But when it gets disrupted or weakens, it can have a subtle influence on the troposphere and potentially help trigger cold snaps.
Interestingly, NOAA also said that temperature records were set in the lower and middle parts of the troposphere, as determined by satellites.
"The cosmic rays from the supernova would be getting down into the lower atmosphere—having an effect on the troposphere," said Melott.
The cosmic rays would have been enough to ionize the planet's troposphere, possibly contributing to a minor mass extinction linked to global cooling.
By far the most important GHG in terms of the radiative properties of the troposphere is water vapor; does anyone call it a pollutant?
The team found a highly significant "pattern match" between seasonal temperature trends and the human influence, or "fingerprint," on the troposphere, according to the statement.
On Earth, the lower atmosphere is divided into two regions: the troposphere, which is closer to the surface, and the stratosphere, which is the upper layer.
The lower troposphere — the atmosphere right above the Earth's surface — had the highest temperature on record, and the upper ocean's heat was close to a record.
That means that, while the temperature decreases the higher up you go in the troposphere, in the stratosphere, the higher up you go, the temperature gets warmer.
There is the main vortex that exists in the stratosphere, about 55,000 feet high, as well as a related circulation lower in the atmosphere, in the troposphere.
Instead, they remain in the expanding troposphere, possibly causing more issues here on the ground, and never get to act as a sun shield for our planet.
That's a bit of a misnomer, because, technically, the satellites in question are in the mid-troposphere, and also the archeology still happens on, or under, the ground.
Steering a Boeing 777 up, down, and around the troposphere and stratosphere sounds like a blast, but the truth is it requires a lot of time, commitment, and money.
The team used temperature measurements taken by satellites to study changes in the size of the seasonal temperature cycle in the troposphere at different points on the planet&aposs surface.
How they did it: Researchers from Lawrence Livermore National Laboratory, Remote Sensing Systems, MIT and other institutions combined 38 years of satellite observations of the troposphere and computer model data.
The Stratollite makes use of a large balloon that lofts payloads into the upper stratosphere, which is the layer of the atmosphere immediately above the troposphere, where most weather occurs.
The cultural history of clouds seemed to be shaped by a procession of amateurs, each of whom projected the ethos of his particular era onto those billowing blank slates in the troposphere.
What they found: The researchers found that human emissions of greenhouse gases have altered the seasonal cycle around the world, as measured in the troposphere, but with ramifications for conditions at the surface.
That is because little has been done to help pilots detect avian threats that materialize at altitudes above 2,500 feet, the portion of the troposphere where roughly 10 percent of bird strikes occur.
Beyond the usual tabloid fodder related to the working class troposphere of Sleaford Mods' music, there is little discussion related to the inner make-up of those who are part of that generation.
The jet stream consists of a corridor of high winds blowing near the top of the troposphere, or about 35,000 feet up, that separates air masses and both steers and helps fuel storm systems.
She complicates that a bit on Will, utilizing a few new toys and tools—including a Moog Mother and a few other synths—to tear straight through the troposphere into the inky blackness beyond.
What is forecast to happen, though, is that the polar vortex in both the stratosphere and troposphere will be displaced without weakening much, and set up camp above Hudson Bay, Canada during much of February.
But when others, including Carl Mears, a senior research scientist at the research company Remote Sensing Systems, reexamined Christy's work in the early 2000s, they found errors that when corrected revealed warming in the troposphere.
On right: a destabilized polar vortex dipping into the U.S. This fickle weather occurs in the lowest part of the atmosphere, the troposphere, which spans from sea level to about six miles above the surface.
In 2015, Mr. Puth was an up-and-coming songwriter when he rocketed into the pop troposphere with the Wiz Khalifa collaboration "See You Again," a moist lump of treacle from the "Furious 7" soundtrack.
"One of the important predictions of numerous models of nuclear winter is that smoke injected into the upper troposphere from urban fires will self-loft high into the stratosphere," the authors wrote in the study.
Satellite data readings from the mid-troposphere—the layer of air from two to six miles above the surface—recorded only the third-highest readings since those records started being kept in 1979, NASA and NOAA reported.
Last year, he talked his way on board a NASA mission in Greenland and shot pictures of melting glaciers and sea ices through the drop window of the military transport plane flying very low in the troposphere.
Most of these particulates, which from space often appear as a brownish haze, get lofted some five to six miles into the troposphere (the lowest part of the atmosphere where weather, like clouds, rain, cyclones, and beyond, occur).
The polar vortex can actually refer to either one of a stacked pair of air masses: one in the lowest part of the Earth's atmosphere or troposphere, and another on top of it in the stratosphere, both rotating counterclockwise.
I flew back across the Atlantic on New Year's Eve and somewhere in the troposphere resolved to begin 2018 by changing the way I sleep in the wake of being deprived of it for a week and a half.
"The purpose of the field campaign was to obtain some of the first global cross-sections of the concentration of trace gases and of dust, smoke, and other particles in the remote troposphere over the Pacific and Atlantic Oceans," according to the paper.
In a new study, scientists from Lawrence Livermore National Laboratory (LLNL) and five otherorganizations show that human action significantly affects the seasonal temperature cycle in the troposphere, or  lowest layer of Earth&aposs atmosphere  — the layer that we live in where weather occurs.
The deadly projectile might ricochet downward, nose tilted up, on layers of atmosphere — the mesosphere, then the stratosphere and troposphere — like an oblate stone on water, in smaller and shallower skips, or it might be directed to pass smoothly through these layers.
I also hurtled through the troposphere on hundreds of airplanes (each round trip from New York to London costs the Arctic another three square meters of ice), bought and sold multiple automobiles and helped my wife put two more Americans onto the planet.
"Our unique location – latitude 63 degrees, and elevation 6,000 feet means our troposphere is some of the thinnest on the planet, which allows you to see the aurora's blues and purples as well as shooting stars more often and brighter than elsewhere," reads Sheldon Chalet's website.
Over the past three years, his absence from the pop troposphere — a void interrupted only by the occasional collaboration, Tumblr post or paparazzi shot — has felt like a position statement against celebrity culture, while simultaneously guaranteeing that Mr. Ocean's fame, turbo-boosted by fervent curiosity, would grow even wider.
Based on computer models and basic physics, scientists had an idea of how temperatures in the troposphere — the layer of air extending from near Earth's surface to about 35,000 feet and where most weather occurs — should be varying from one season to the next as the world warms overall.
For much of the week, the jet stream — the fast-moving current of air at the top of the troposphere, where jetliners cruise — has carved a path that has directed two atmospheric rivers into the U.S.  The first has steered badly needed rain and mountain snow to drought-plagued California.
It's always been easy, a cop-out maybe, to cast Marshall as a specifically south London musician—one couched in the semantics of Joe Strummer or The Damned and their respective influences, bound together by the aural troposphere of trip-hop and rap and set to the weed-scented scene of roaming nocturnally through SE16 in moonlit autumnal rain.
Although variations do occur, the temperature usually declines with increasing altitude in the troposphere because the troposphere is mostly heated through energy transfer from the surface. Thus, the lowest part of the troposphere (i.e. Earth's surface) is typically the warmest section of the troposphere. This promotes vertical mixing (hence, the origin of its name in the Greek word τρόπος, tropos, meaning "turn").
The troposphere contains roughly 80% of the mass of Earth's atmosphere. The troposphere is denser than all its overlying atmospheric layers because a larger atmospheric weight sits on top of the troposphere and causes it to be most severely compressed. Fifty percent of the total mass of the atmosphere is located in the lower of the troposphere. Nearly all atmospheric water vapor or moisture is found in the troposphere, so it is the layer where most of Earth's weather takes place.
Most weather phenomena occur in the troposphere,Glossary of Meteorology. Hydrosphere. Retrieved on 2008-06-27.Glossary of Meteorology. Troposphere. Retrieved on 2008-06-27.
Troposphere 1, which was planned for launch in April 2007, was canceled due to technical problems. Troposphere 3 scheduled for October 12, 2007 was also a failure.
The tropopause is the boundary region between the troposphere and the stratosphere. Measuring the temperature change with height through the troposphere and the stratosphere identifies the location of the tropopause. In the troposphere, temperature decreases with altitude. In the stratosphere, however, the temperature remains constant for a while and then increases with altitude.
The upper part of the troposphere (i.e., above the inversion layer) is called the free troposphere and it extends up to the tropopause (the boundary in the Earth's atmosphere between the troposphere and the stratosphere). In tropical and mid- latitudes during daytime, the Free convective layer can comprise the entire troposphere, which is up to 10 km to 18 km in the Intertropical convergence zone. The ABL is of the most important with respect to the emission, transport and dispersion of airborne pollutants.
Atop the troposphere is the tropopause, which is the border between the troposphere and stratosphere. The tropopause is an inversion layer, where the air temperature ceases to decrease with height and remains constant through its thickness. The word troposphere is derived from the Greek tropos (meaning "turn, turn toward, change") and sphere (as in the Earth), reflecting the fact that rotational turbulent mixing plays an important role in the troposphere's structure and behaviour. Most of the phenomena associated with day-to-day weather occur in the troposphere.
The Democratic Republic of the Congo has a rocketry program called Troposphere.
By some definitions, Venus has no stratosphere. The troposphere begins at the surface and extends up to an altitude of 65 kilometres (an altitude at which the mesosphere has already been reached on Earth). At the top of the troposphere, temperature and pressure reach Earth-like levels. Winds at the surface are a few metres per second, reaching 70 m/s or more in the upper troposphere.
The average height of the troposphere is in the tropics, in the middle latitudes, and in the polar regions in winter. The total average height of the troposphere is . The lowest part of the troposphere, where friction with the Earth's surface influences airflow, is the planetary boundary layer. This layer is typically a few hundred meters to deep depending on the landform and time of day.
DTA is currently working on the next rocket, Troposphere 6. Troposphere 6 is a three-stage solid-propellant rocket and Keka claimed that the rocket could reached up to altitude of 200 km. Troposphere 6 was scheduled to be launched in the end of 2016. A crowd funding has been set up to support Congolese space rocket set to launch sometime between fall of 2019 to spring of 2020.
The tropopause is the boundary in the Earth's atmosphere between the troposphere and the stratosphere. It is a thermodynamic gradient stratification layer, marking the end of the troposphere. It lies, on average, at above equatorial regions, and about over the polar regions.
Space Shuttle Endeavour to straddle the stratosphere and mesosphere in this photo. The troposphere, which contains clouds, appears orange in this photo. Diagram showing the five primary layers of the Earth's atmosphere: exosphere, thermosphere, mesosphere, stratosphere, and troposphere. The layers are to scale.
His research has substantially advanced understanding of the atmospheric chemistry of the troposphere and the stratosphere.
Central to Lumas' book is the "Troposphere" – a place where all consciousness is connected and you can enter other people's minds and read their thoughts. The book contains the recipe for a homeopathic formula that Lumas' hero uses to enter the Troposphere. Manto uses the recipe to reproduce the formula and subsequently enters the Troposphere herself. The book mentions that her surname is fictitious and based on an anagram; Ariel Manto is an anagram of I am not real.
In the vertical direction, winds are strongest near the surface and decay with height within the troposphere.
The Google Actual Cloud Platform is the world's first public cloud running on servers in the troposphere.
After the success of this launch, the Congolese government decided to get involved with the Troposphere project.
The troposphere is the lowest and densest part of the atmosphere and is characterised by a decrease in temperature with altitude. The temperature falls from about at the base of the nominal troposphere at −300 km to at 50 km. The temperatures in the coldest upper region of the troposphere (the tropopause) actually vary in the range between depending on planetary latitude. The tropopause region is responsible for the vast majority of Uranus's thermal far infrared emissions, thus determining its effective temperature of .
Troposphere 4 is the second successfully launched experimental rocket of the Troposphere program, managed by Jean-Patrice Keka. The rocket with a thrust of 1 ton was launched on July 10, 2008, 5:40 pm from Menkao, east of Kinshasa. The rocket reached an altitude of after 47 seconds, with a speed of Mach 2.7. The launch of the Troposphere 4 rocket took place in the presence of the Congolese Minister of Higher Education, University and Scientific Research, Leonard Masuga Rugamika.
The lower troposphere trend derived from UAH satellites (+0.128 °C/decade) is currently lower than both the GISS and Hadley Centre surface station network trends (+0.161 and +0.160 °C/decade respectively), while the RSS trend (+0.158 °C/decade) is similar. However, if the expected trend in the lower troposphere is indeed higher than the surface, then given the surface data, the troposphere trend would be around 0.194 °C/decade, making the UAH and RSS trends 66% and 81% of the expected value respectively.
Tropospheric Emission Spectrometer or TES was a satellite instrument designed to measure the state of the earth's troposphere.
The orange layer is the troposphere, which gives way to the whitish stratosphere and then the blue mesosphere.
This system covered only the tropospheric cloud types, but the discovery of clouds above the troposphere during the late 19th century eventually led to the creation of separate classification schemes using common names for these very high clouds, which were still broadly similar to some cloud forms identified in the troposphere.
The troposphere is the lowest and densest part of the atmosphere and is characterised by a decrease in temperature with altitude. The temperature falls from about 320 K at the base of the troposphere at −300 km to about 53 K at 50 km. The temperature at the cold upper boundary of the troposphere (the tropopause) actually varies in the range between 49 and 57 K depending on planetary latitude, with the lowest temperature reached near 25° southern latitude. The troposphere holds almost all of the mass of the atmosphere, and the tropopause region is also responsible for the vast majority of the planet's thermal far infrared emissions, thus determining its effective temperature of . The troposphere is believed to possess a highly complex cloud structure; water clouds are hypothesised to lie in the pressure range of , ammonium hydrosulfide clouds in the range of , ammonia or hydrogen sulfide clouds at between 3 and 10 bar and finally thin methane clouds at .
A surface weather analysis for the United States on October 21, 2006. High-pressure areas form due to downward motion through the troposphere, the atmospheric layer where weather occurs. Preferred areas within a synoptic flow pattern in higher levels of the troposphere are beneath the western side of troughs. On weather maps, these areas show converging winds (isotachs), also known as convergence, near or above the level of non-divergence, which is near the 500 hPa pressure surface about midway up through the troposphere, and about half the atmospheric pressure at the surface.
If the Sun was responsible for observed warming, warming of the troposphere at the surface and warming at the top of the stratosphere would be expected as increase solar activity would replenish ozone and oxides of nitrogen., p. 20. The stratosphere has a reverse temperature gradient than the troposphere so as the temperature of the troposphere cools with altitude, the stratosphere rises with altitude. Hadley cells are the mechanism by which equatorial generated ozone in the tropics (highest area of UV irradiance in the stratosphere) is moved poleward.
Water at the top of the troposphere, particularly in liquid and solid states, cools as it emits net photons to space. Neighboring gas molecules other than water (e.g. Nitrogen) are cooled by passing their heat kinetically to the water. This is why temperatures at the top of the troposphere (known as the tropopause) are about -50 degrees Celsius.
During fall, winter, and spring, the atmosphere over continents can be cold enough through the depth of the troposphere to cause snowfall.
Furthermore, through many traditions, we know also that by the air of our breathing, we absorb cosmical particles coming from the troposphere.
The program was financed by DTA at the beginning, but after success of the Troposphere 2 and 4 rockets project gained government support.
Climate models predict that as the surface warms, so should the global troposphere. Globally, the troposphere (at the TLT altitude at which the MSU sounder measure) is predicted to warm about 1.2 times more than the surface; in the tropics, the troposphere should warm about 1.5 times more than the surface. However, in the 2005 CCSP report it was noted that the use of fingerprinting techniques on data yielded that "Volcanic and human-caused fingerprints were not consistently identifiable in observed patterns of lapse rate change." (Where "lapse rate" refers to the change in temperature iwith altitude).
The troposphere is thought to have a highly complex cloud structure; water clouds are hypothesised to lie in the pressure range of , ammonium hydrosulfide clouds in the range of , ammonia or hydrogen sulfide clouds at between and finally directly detected thin methane clouds at . The troposphere is a dynamic part of the atmosphere, exhibiting strong winds, bright clouds and seasonal changes.
Temperature trends in the lower stratosphere, mid to upper troposphere, lower troposphere, and surface, 1957–2005. The lower and middle atmosphere are heating due to the enhanced greenhouse effect. Increased greenhouse gases cause the higher parts of the atmosphere, the stratosphere to cool. This has been observed by a set of satellites since 1979 (the Microwave sounding unit) and radiosonde data.
The atmosphere of Jupiter lacks a clear lower boundary and gradually transitions into the liquid interior of the planet. From lowest to highest, the atmospheric layers are the troposphere, stratosphere, thermosphere and exosphere. Each layer has characteristic temperature gradients. The lowest layer, the troposphere, has a complicated system of clouds and hazes, comprising layers of ammonia, ammonium hydrosulfide and water.
They are most commonly seen as orographic mountain-wave clouds, but can occur anywhere in the troposphere where there is strong wind shear combined with sufficient airmass stability to maintain a generally flat cloud structure. These two species can be found in the high, middle, or low levels of the troposphere depending on the stratocumuliform genus or genera present at any given time.
The stratosphere is the second-lowest layer of Earth's atmosphere. It lies above the troposphere and is separated from it by the tropopause. This layer extends from the top of the troposphere at roughly above Earth's surface to the stratopause at an altitude of about . The atmospheric pressure at the top of the stratosphere is roughly 1/1000 the pressure at sea level.
The troposphere is the lowest layer of the Earth's atmosphere. It extends from the ground up to a variable height of approximately 14 kilometers above sea level. Ozone is least concentrated in the ground layer (or planetary boundary layer) of the troposphere. Ground level or tropospheric ozone is created by chemical reactions between oxides of nitrogen (NOx gases) and volatile organic compounds (VOCs).
The first successful rocket, Troposphere 2 (30.94 kg and 0.19 m in diameter), launched in 2007 and reached an altitude of 1500 m (1.5 km).
Galileo atmospheric probe stopped transmitting at a depth of 132 km below the 1 bar "surface" of Jupiter. The atmosphere of Jupiter is classified into four layers, by increasing altitude: the troposphere, stratosphere, thermosphere and exosphere. Unlike the Earth's atmosphere, Jupiter's lacks a mesosphere. Jupiter does not have a solid surface, and the lowest atmospheric layer, the troposphere, smoothly transitions into the planet's fluid interior.
The magnetosphere shields the surface of Earth from the charged particles of the solar wind. (image not to scale.) The troposphere, stratosphere, mesosphere, thermosphere, and exosphere are the five layers which make up Earth's atmosphere. 75% of the gases in the atmosphere are located within the troposphere, the lowest layer. In all, the atmosphere is made up of about 78.0% nitrogen, 20.9% oxygen, and 0.92% argon.
Such strong cloud-top winds cause a phenomenon known as the super-rotation of the atmosphere. In other words, these high-speed winds circle the whole planet faster than the planet itself rotates. The super-rotation on Venus is differential, which means that the equatorial troposphere super-rotates more slowly than the troposphere at the midlatitudes. The winds also have a strong vertical gradient.
Subtropical high pressure zones form under the descending portion of the Hadley cell circulation. Upper-level high-pressure areas lie over tropical cyclones due to their warm core nature. Surface anticyclones form due to downward motion through the troposphere, the atmospheric layer where weather occurs. Preferred areas within a synoptic flow pattern in higher levels of the troposphere are beneath the western side of troughs.
Whether or not the atmosphere has stability depends partially on the moisture content. In a very dry troposphere, a temperature decrease with height less than 9.8C per kilometer ascent indicates stability, while greater changes indicate instability. This lapse rate is known as the dry adiabatic lapse rate. In a completely moist troposphere, a temperature decrease with height less than 6C per kilometer ascent indicates stability, while greater changes indicate instability.
If it is not destroyed in the troposphere, methane will last approximately 120 years before it is eventually destroyed in Earth's next atmospheric layer: the stratosphere. Destruction in the stratosphere occurs the same way that it does in the troposphere: methane is oxidized to produce carbon dioxide and water vapor. Based on balloon-borne measurements since 1978, the abundance of stratospheric methane has increased by between 1978 and 2003.
In a broad sense, haloalkanes that contain no hydrogen are stable in the troposphere and decompose only in the stratosphere. Those compounds that contain hydrogen also react with OH radicals and can therefore be decomposed in the troposphere, as well. The ozone depletion potential increases with the heavier halogens since the C-X bond strength is lower. Note the trend of the CClF2-X series in the table below.
The circulation in Venus's troposphere follows the so-called cyclostrophic flow. Its windspeeds are roughly determined by the balance of the pressure gradient and centrifugal forces in almost purely zonal flow. In contrast, the circulation in the Earth's atmosphere is governed by the geostrophic balance. Venus's windspeeds can be directly measured only in the upper troposphere (tropopause), between 60–70 km, altitude, which corresponds to the upper cloud deck.
They are generally seen when a warm or occluded front is approaching. They are very high in the troposphere and generally mean that precipitation, usually rain, is approaching.
From the ground upwards through the troposphere temperature decreases with height; from the tropopause upwards through the stratosphere temperature increases with height. Such variations are examples of temperature gradients.
Radio waves in the VHF and UHF bands can travel somewhat beyond the visual horizon due to refraction in the troposphere, the bottom layer of the atmosphere below 20 km. This is due to changes in the refractive index of air with temperature and pressure. Tropospheric delay is a source of error in radio ranging techniques, such as the Global Positioning System (GPS).Frank Kleijer (2004), Troposphere Modeling and Filtering for Precise GPS Leveling .
Cirriform clouds in the troposphere are of the genus cirrus and have the appearance of detached or semimerged filaments. They form at high tropospheric altitudes in air that is mostly stable with little or no convective activity, although denser patches may occasionally show buildups caused by limited high-level convection where the air is partly unstable. Clouds resembling cirrus can be found above the troposphere but are classified separately using common names.
Earth's atmosphere consists of a number of layers that differ in properties such as composition, temperature and pressure. The lowest layer is the troposphere, which extends from the surface to the bottom of the stratosphere. Three quarters of the atmosphere's mass resides within the troposphere, and is the layer within which the Earth's terrestrial weather develops. The depth of this layer varies between 17 km at the equator to 7 km at the poles.
Cumulus mediocris cloud surrounded by stratocumulus On Earth, the common weather phenomena include wind, cloud, rain, snow, fog and dust storms. Less common events include natural disasters such as tornadoes, hurricanes, typhoons and ice storms. Almost all familiar weather phenomena occur in the troposphere (the lower part of the atmosphere). Weather does occur in the stratosphere and can affect weather lower down in the troposphere, but the exact mechanisms are poorly understood.
With these errors corrected, the UAH data showed a 0.07 °C/decade increase in lower troposphere temperature. Some discrepancies between the UAH temperature measurements and temperatures measured by other groups remain, with (as of 2019) the lower troposphere temperature trend from 1979-2019 calculated as +0.13 °C/decade by UAH, and calculated at +0.208 °C/decade by RSS.Remote Sensing Services, Earth Microwave Data Center, MSU & AMSU Time Series Trend Browse Tool. Retrieved 15 Jan. 2020.
The low étage is found from surface up to at all latitudes. Principal cloud types found in the low levels of the troposphere include stratocumulus, stratus, and small fair weather cumulus.
High-pressure systems form due to downward motion through the troposphere, the atmospheric layer where weather occurs. Preferred areas within a synoptic flow pattern in higher levels of the troposphere are beneath the western side of troughs. On weather maps, these areas show converging winds (isotachs), also known as confluence, or converging height lines near or above the level of non-divergence, which is near the 500 hPa pressure surface about midway up through the troposphere.Glossary of Meteorology (2009).
Idealized ABL structureThe ABL is the lowest part of the Earth's troposphere, loosely about the altitude zone 0 km to 1.5 km. The ABL is the only part of the troposphere directly affected by daily cycled contact with the Earth's surface, so the ABL is directly affected by forcings originating at the surface. Such forcings include: heat flux, moisture flux, convection, friction, pollutant emission, and topographically modified flow. Response times to these forcings typically are an hour or less.
Temperature profile of the Uranian troposphere and lower stratosphere. Cloud and haze layers are also indicated. The Uranian atmosphere can be divided into three main layers: the troposphere, between altitudes of −300 and 50 km and pressures from 100 to 0.1 bar; the stratosphere, spanning altitudes between 50 and 4000 km and pressures between and the thermosphere/exosphere extending from 4000 km to as high as a few Uranus radii from the surface. There is no mesosphere.
It can also be produced by the reaction of methane with the hydroxyl radical: :OH• \+ CH4 → + H2O This process begins the major removal mechanism of methane from the atmosphere. The reaction occurs in the troposphere or stratosphere. In addition to being the largest known sink for atmospheric methane, this reaction is one of the most important sources of water vapor in the upper atmosphere. This reaction in the troposphere gives a methane lifetime of 9.6 years.
Tropospheric propagation describes electromagnetic propagation in relation to the troposphere. The service area from a VHF or UHF radio transmitter extends to just beyond the optical horizon, at which point signals start to rapidly reduce in strength. Viewers living in such a "deep fringe" reception area will notice that during certain conditions, weak signals normally masked by noise increase in signal strength to allow quality reception. Such conditions are related to the current state of the troposphere.
Space Shuttle Endeavour silhouetted against the atmosphere. The orange layer is the troposphere, the white layer is the stratosphere, and the blue layer is the mesosphere. (The shuttle is actually orbiting at an altitude of more than , far above all three layers.) The troposphere is the lowest layer of Earth's atmosphere, and is also where nearly all weather conditions take place. It contains 75% of the atmosphere's mass and 99% of the total mass of water vapour and aerosols.
In addition, minor changes have been made in the representation of convective processes, and through the choice of a slightly different vertical discretization within the troposphere, as well as changed model parameters.
Three of the five physical forms in the troposphere are also seen at these higher levels, stratiform, cirriform, and stratocumuliform, although the tops of very large cumulonimbiform clouds can penetrate the lower stratosphere.
The structure of an MCC can be separated into three layers. The low-levels of the MCC near the surface, the mid-levels in the middle of the troposphere, and the upper-levels in the upper-troposphere. Near the surface, the MCC exhibits high pressure, with an outflow boundary, or mesoscale cold front, at its leading edge. This high pressure is caused by the cooling of the air from the evaporation of rainfall (commonly referred to as a cold pool).
The Sahara is the world's largest low- latitude hot desert. It is located in the horse latitudes under the subtropical ridge, a significant belt of semi-permanent subtropical warm-core high pressure where the air from the upper troposphere usually descends, warming and drying the lower troposphere and preventing cloud formation. The permanent absence of clouds allows unhindered light and thermal radiation. The stability of the atmosphere above the desert prevents any convective overturning, thus making rainfall virtually non-existent.
In a microwave beam directed at an angle into the sky, a small amount of the power will be randomly scattered as the beam passes through the troposphere. A sensitive receiver beyond the horizon with a high gain antenna focused on that area of the troposphere can pick up the signal. This technique has been used at frequencies between 0.45 and 5 GHz in tropospheric scatter (troposcatter) communication systems to communicate beyond the horizon, at distances up to 300 km.
In the Earth's atmosphere, gravity waves are a mechanism that produce the transfer of momentum from the troposphere to the stratosphere and mesosphere. Gravity waves are generated in the troposphere by frontal systems or by airflow over mountains. At first, waves propagate through the atmosphere without appreciable change in mean velocity. But as the waves reach more rarefied (thin) air at higher altitudes, their amplitude increases, and nonlinear effects cause the waves to break, transferring their momentum to the mean flow.
The troposphere is the lowest layer of Earth's atmosphere. It extends from Earth's surface to an average height of about , although this altitude varies from about at the geographic poles to at the Equator, with some variation due to weather. The troposphere is bounded above by the tropopause, a boundary marked in most places by a temperature inversion (i.e. a layer of relatively warm air above a colder one), and in others by a zone which is isothermal with height.
Ozone in the troposphere is considered a greenhouse gas, and may contribute to global warming. Photochemical and chemical reactions involving ozone drive many of the chemical processes that occur in the troposphere by day and by night. At abnormally high concentrations (the largest source being emissions from combustion of fossil fuels), it is a pollutant, and a constituent of smog. Its levels have increased significantly since the industrial revolution, as NOx gasses & VOCs are some of the byproducts of combustion.
Mirage over a hot road, with the appearance of "fake water" on its surface Within an unstable layer in the troposphere, the lifting of air parcels will occur, and continue for as long as the nearby atmosphere remains unstable. Once overturning through the depth of the troposphere occurs (with convection being capped by the relatively warmer, more stable layer of the stratosphere), deep convective currents lead to thunderstorm development when enough moisture is present. Over warm ocean waters and within a region of the troposphere with light vertical wind shear and significant low level spin (or vorticity), such thunderstorm activity can grow in coverage and develop into a tropical cyclone. Over hot surfaces during warm days, unstable dry air can lead to significant refraction of the light within the air layer, which causes inferior mirages.
These echoes come from equatorial irregularities generated in troposphere, stratosphere, mesosphere, equatorial electrojet, E and F region. Given the strength of the echoes, usually low power transmitters and/or smaller antenna sections are used.
In the tropics, basic physical considerations, climate models, and multiple independent data sets indicate that the warming trend due to well-mixed greenhouse gases should be faster in the troposphere than at the surface.
In addition, they transport large amount of water vapor into the upper troposphere, dominating the variations of global UTWV. Price [2000] suggested that changes in the UTWV can be derived from records of Schumann resonances.
The net atmospheric heating due to aerosol absorption causes the air to warm and convect upwards, increasing the concentration of moisture in the mid-troposphere and providing positive feedback that stimulates further heating of aerosols.
Condensation trails with Cirrocumulus homogenitus (Cca) and Cirrostratus homogenitu (Csa) observed over Barcelona (Spain, November 2010). Despite the fact that the three genera of high clouds, Cirrus, Cirrocumulus and Cirrostratus, form at the top of the troposphere, far from the earth surface, they may have an anthropogenic origin. In this case, the process that causes their formation is almost always the same: commercial and military aircraft flight. Exhaust products from the combustion of the kerosene expelled by engines provide water vapor to this region of the troposphere.
They are believed to be due mainly to moist convection within Jupiter's troposphere. Storms are actually tall convective columns (plumes), which bring the wet air from the depths to the upper part of the troposphere, where it condenses in clouds. A typical vertical extent of Jovian storms is about 100 km; as they extend from a pressure level of about 5–7 bar, where the base of a hypothetical water cloud layer is located, to as high as 0.2–0.5 bar.Sanchez- Lavega et al.
SAPHIRIn the 20-meter long SAPHIR chamber (Simulation of Atmospheric PHotochemistry In a large Reaction Chamber), a group in the Institute of Chemistry and Dynamics of the Geosphere - Troposphere (ICG-II) investigates photochemical reactions in the atmosphere.
There is no tropopause in the jet standard atmosphere. In the ISA, the tropopause is the height at which the temperature stops decreasing, and is also the end of the troposphere and the start of the stratosphere.
The rest of the atmosphere is composed of the remaining part of the planetary boundary layer (up to around 1000 m) and the troposphere or free atmosphere. In the free atmosphere, geostrophic wind relationships should be used.
Turbulence at Triton's surface creates a troposphere (a "weather region") rising to an altitude of 8 km. Streaks on Triton's surface left by geyser plumes suggest that the troposphere is driven by seasonal winds capable of moving material of over a micrometre in size. Unlike other atmospheres, Triton's lacks a stratosphere, and instead has a thermosphere from altitudes of 8 to 950 km, and an exosphere above that. The temperature of Triton's upper atmosphere, at , is higher than that at its surface, due to heat absorbed from solar radiation and Neptune's magnetosphere.
The abundance of methane, ethane and acetylene at Neptune's equator is 10–100 times greater than at the poles. This is interpreted as evidence for upwelling at the equator and subsidence near the poles because photochemistry cannot account for the distribution without meridional circulation. In 2007, it was discovered that the upper troposphere of Neptune's south pole was about 10 K warmer than the rest of its atmosphere, which averages approximately . The temperature differential is enough to let methane, which elsewhere is frozen in the troposphere, escape into the stratosphere near the pole.
The part of the ABL between the Earth's surface and the bottom of the inversion layer is known as the mixing layer. Almost all of the airborne pollutants emitted into the ambient atmosphere are transported and dispersed within the mixing layer. Some of the emissions penetrate the inversion layer and enter the free troposphere above the ABL. In summary, the layers of the Earth's atmosphere from the surface of the ground upwards are: the ABL made up of the mixing layer capped by the inversion layer; the free troposphere; the stratosphere; the mesosphere and others.
More specifically, it studies about the transport of water from the troposphere to the stratosphere, and circulation of the stratosphere and mesosphere driven by internal gravity waves. Convective processes of the troposphere affect the transport of water vapour-a green house gas, and its circulation in both the stratosphere and mesosphere. By analysing the processes that occur in these layers, can improve atmospheric models, and provide a better understanding of Earth's climate and weather. The experiment also studies how much water the cloud turrets can carry into the stratosphere, and how lightning influences their formation.
From Earth's surface to the top of the stratosphere (50 km) is just under 1% of Earth's radius. The stratosphere () is the second major layer of Earth's atmosphere, just above the troposphere, and below the mesosphere. The stratosphere is stratified (layered) in temperature, with warmer layers higher and cooler layers closer to the Earth; this increase of temperature with altitude is a result of the absorption of the Sun's ultraviolet radiation (shortened UV) by the ozone layer. This is in contrast to the troposphere, near the Earth's surface, where temperature decreases with altitude.
The border between the troposphere and stratosphere, the tropopause, marks where this temperature inversion begins. Near the equator, the lower edge of the stratosphere is as high as , at midlatitudes around , and at the poles about Temperatures range from an average of near the tropopause to an average of near the mesosphere. Stratospheric temperatures also vary within the stratosphere as the seasons change, reaching particularly low temperatures in the polar night (winter). Winds in the stratosphere can far exceed those in the troposphere, reaching near in the Southern polar vortex.
TES Mission LogoTES was a high-resolution infrared Fourier Transform spectrometer and provided key data for studying tropospheric chemistry, troposphere-biosphere interaction, and troposphere-stratosphere exchanges. It was built for NASA by the Jet Propulsion Laboratory, California Institute of Technology in Pasadena, California. It was successfully launched into polar orbit by a Delta II 7920-10L rocket aboard NASA's third Earth Observing Systems spacecraft (EOS- Aura) at 10:02 UTC on July 15, 2004. Originally planned as a 5-year mission, it was decommissioned after almost 14 years on January 31, 2018.
The dominant sink of methane in the troposphere is reaction with hydroxyl radicals that are formed by reaction of singlet oxygen atoms with water vapor. Methane is also present in the stratosphere, where methane's concentration decreases with height.
Retrieved May 25, 2008. Sites launch radiosondes, which rise through the depth of the troposphere and well into the stratosphere.Gaffen, Dian J. (June 7, 2007). "Radiosonde Observations and Their Use in SPARC- Related Investigations". Retrieved 2008-05-25.
While primarily an astronomical research facility, the observatory also hosts two geophysics research stations, one studying the mesosphere and thermosphere, and one using lasers to probe the troposphere and stratosphere, studying aerosol and ozone content, using lidar techniques.
It is also possible to define the tropopause in terms of chemical composition. For example, the lower stratosphere has much higher ozone concentrations than the upper troposphere, but much lower water vapor concentrations, so appropriate cutoffs can be used.
Arguably the most striking of all gravitational intrusions, is the atmospheric gravity current generated from a large, 'Plinean' volcanic eruption. In which case the volcano's overhanging 'umbrella' is an example of an intrusion laterally intruding into the stratified Troposphere.
Diagram showing the five primary layers of the Earth's atmosphere: exosphere, thermosphere, mesosphere, stratosphere, and troposphere. The layers are to scale. From Earth's surface to the top of the stratosphere (50 km) is just under 1% of Earth's radius.
SCIAMACHY was conceived to improve global knowledge and understanding of a variety of issues of importance for the chemistry and physics of the Earth's atmosphere (troposphere, stratosphere and mesosphere) and potential changes resulting from either anthropogenic behavior or natural phenomena.
80% of that mass is concentrated within the troposphere. The mass of the thermosphere above about 85 km is only 0.002% of the total mass. Therefore, no significant energetic feedback from the thermosphere to the lower atmospheric regions can be expected.
They also carry heat and energy away from the tropics and transport it toward temperate latitudes, which makes them an important part of the global atmospheric circulation mechanism. As a result, tropical cyclones help to maintain equilibrium in the Earth's troposphere.
Group of iberulites observed under SEM. The arrows show vortex position. Iberulites are a particular type of microspherulites that develop in the atmosphere (troposphere), finally falling to the earth's surface. The name comes from the Iberian Peninsula where they were discovered.
Given that the lapse rate is not a conservative quantity when the tropopause is considered for stratosphere-troposphere exchanges studies, there exists an alternative definition named dynamic tropopause. It is formed with the aid of potential vorticity, which is defined as the product of the isentropic density, i.e. the density that arises from using potential temperature as the vertical coordinate, and the absolute vorticity, given that this quantity attains quite different values for the troposphere and the stratosphere. Instead of using the vertical temperature gradient as the defining variable, the dynamic tropopause surface is expressed in potential vorticity units (PVU).
The planetary boundary layer is the portion of the troposphere that is influenced by the interaction with the surface of the earth and will adjust to surface forcings within a timescale of 1 hour. The planetary boundary layer is characterized by turbulence during the daytime and by stability during the night. At the top of the planetary boundary layer, there is a stable layer that is frequently termed the inversion layer as temperature tends to increase with height in contrast to much of the troposphere. The planetary boundary layer can have lower level clouds located around the capping inversion top.
TOMCAT/SLIMCAT is an off-line chemical transport model (CTM), which models the time-dependent distribution of chemical species in the troposphere and stratosphere. It can be used to study topics such as ozone depletion and tropospheric pollution, and was one of the models used the IPCC report on Aviation and the Global Atmosphere . It incorporates a choice of detailed chemistry schemes for the troposphere or stratosphere, and an optional chemical data assimilation scheme. The original model code, called the Toulouse Off-line Model of Chemistry And Transport (TOMCAT), was written by Martyn Chipperfield at Météo France.
Polar lows form for a number of different reasons, and a spectrum of systems is observed on satellite imagery. A number of lows develop on horizontal temperature gradients through baroclinic instability, and these can have the appearance of small frontal depressions. At the other extreme are the polar lows with extensive cumulonimbus clouds, which are often associated with cold pools in the mid- to upper-troposphere. During winter, when cold- core lows with temperatures in the mid-levels of the troposphere reach move over open waters, deep convection forms which allows polar low development to become possible.
However, there are cases that TUTTs assist the genesis and intensification of tropical cyclones by providing additional forced ascent near the storm center and an efficient outflow channel in the upper troposphere. This is most likely near its most westward and equatorward periphery.
High clouds form in the highest and coldest region of the troposphere from about 5 to 12 km (16,500 to 40,000 ft) in temperate latitudes. At this altitude water almost always freezes so high clouds are generally composed of ice crystals or supercooled water droplets.
Some of the French words that made their way into the English language were coined by French speaking inventors, discoverers or pioneers, or scientists: cinema, television, helicopter, parachute, harmonium, bathyscaphe, lactose, lecithin, bacteriophage, chlorophyll, mastodon, pterodactyl, oxide, oxygen, hydrogen, carbon, photography, stethoscope, thermometer, stratosphere, troposphere.
There were 9 different MSUs launched; the most recent one on NOAA-14. They provided measurements of the temperature of the troposphere and lower stratosphere until 1998, when the first AMSU was deployed. AMSU provides many more channels and finer resolution (about 50 km).
His research uncovered how clouds and aerosols influence the chemistry of the troposphere, and showed that cloud convection has a major impact on tropospheric ozone.Lelieveld, J. and P.J. Crutzen (1990) Influences of cloud photochemical processes on tropospheric ozone. Nature 343, 227-233, doi:10.1038/343227a0.
Cirrus fibratus clouds in March Clouds in the troposphere assume five physical forms based on structure and process of formation. These forms are commonly used for the purpose of satellite analysis. They are given below in approximate ascending order of instability or convective activity.
Nitrous acid is involved in the ozone budget of the lower atmosphere, the troposphere. The heterogeneous reaction of nitric oxide (NO) and water produces nitrous acid. When this reaction takes place on the surface of atmospheric aerosols, the product readily photolyses to hydroxyl radicals.
This coldest layer of the atmosphere, where the lapse rate changes from positive (in the troposphere) to negative (in the stratosphere), is defined as the tropopause. Thus, the tropopause is an inversion layer, and there is little mixing between the two layers of the atmosphere.
The essentials of the modern nomenclature system for tropospheric clouds were proposed by Luke Howard, a British manufacturing chemist and an amateur meteorologist with broad interests in science, in an 1802 presentation to the Askesian Society. Very low stratiform clouds that touch the Earth's surface are given the common names, fog and mist, which are not included with the Latin nomenclature of clouds that form aloft in the troposphere. Above the troposphere, stratospheric and mesospheric clouds have their own classifications with common names for the major types and alpha-numeric nomenclature for the subtypes. They are characterized by altitude as very high level (polar stratospheric) and extreme level (polar mesospheric).
The temperature of the troposphere decreases with height until it reaches a minimum at the tropopause, which is the boundary between the troposphere and stratosphere. On Jupiter, the tropopause is approximately 50 km above the visible clouds (or 1 bar level), where the pressure and temperature are about 0.1 bar and 110 K. In the stratosphere, the temperatures rise to about 200 K at the transition into the thermosphere, at an altitude and pressure of around 320 km and 1 μbar.Sieff et al. (1998) In the thermosphere, temperatures continue to rise, eventually reaching 1000 K at about 1000 km, where pressure is about 1 nbar.
Usually, an anticyclone in the upper layers of the troposphere above the storm must be present as well—for extremely low surface pressures to develop. This is because air must be converging towards the low pressure at the surface which then forces the air to rise very rapidly in the eyewall of the storm, and due to conservation of mass requires a divergence of wind at the top of the troposphere. This process is aided by an upper-level anticyclone which helps channel this air away from the cyclone efficiently. Hot towers have been implicated in tropical cyclone rapid intensification, though they have diagnostically seen varied impacts across basins.
Ozone in the atmosphere can be measured by remote sensing technology, or by in-situ monitoring technology. Because ozone absorbs light in the UV spectrum, the most common way to measure ozone is to measure how much of this light spectrum is absorbed in the atmosphere. Because the stratosphere has higher ozone concentration than the troposphere, it is important for remote sensing instruments to be able to determine altitude along with the concentration measurements. The TOMS-EP instrument aboard a satellite from NASA is an example of an ozone layer measuring satellite, and TES is an example of an ozone measuring satellite that is specifically for the troposphere.
Larkin studied astrophysics at the University of Leeds, graduating in 1996. She joined Imperial College London for her graduate studies, working on climate modelling, and completed her PhD in 2000 on the effects of solar variability on climate using atmospheric models of the troposphere and stratosphere.
DK Space Encyclopedia: Atmosphere of Venus p 58. Near the poles are anticyclonic structures called polar vortices. Each vortex is double-eyed and shows a characteristic S-shaped pattern of clouds. Above there is an intermediate layer of mesosphere which separates the troposphere from the thermosphere.
The lower stratosphere is centered around 18 kilometers above Earth's surface. The stratosphere image is dominated by blues and greens, which indicates a cooling over time. Diagram showing the five primary layers of the Earth's atmosphere: exosphere, thermosphere, mesosphere, stratosphere, and troposphere. The layers are to scale.
Some bird species have been reported to fly at the upper levels of the troposphere. On November 29, 1973, a Rüppell's vulture (Gyps rueppelli) was ingested into a jet engine above the Ivory Coast, and bar-headed geese (Anser indicus) reportedly overfly Mount Everest's summit, which is .
In the 1980s, improved observations allowed detection of teleconnections at larger distances throughout the troposphere. Concomitantly, the theory emerged that such patterns could be understood through the dispersion of Rossby waves due to the spherical geometry of the Earth. This is sometimes called the "proto- model".
The improved vertical resolution of OMPS data products allows for better testing and monitoring of the complex chemistry involved in ozone destruction near the troposphere. OMPS products, when combined with cloud predictions, also help produce better ultraviolet index forecasts."Ozone Mapper Profiler Suite." NASA Goddard Spaceflight Center.
In a large system under even homogeneous external force, like the earth atmosphere under gravity, the intensive parameters (p, T, \rho, i.e. Pressure, temperature, and density respectively) should be studied locally having even in equilibrium different values in different places far from each other (see thermodynamic models of troposphere].
The release of tephra into the troposphere impacts the environment physically and chemically. Physically, volcanic blocks damage local flora and human settlements. Ash damages communication and electrical systems, coats forests and plant life reducing photosynthesis, and pollutes groundwater. Tephra changes below and above ground air and water movement.
This leads to a uniform temperature in the troposphere. While heat is transported from the equator to the poles mainly via the atmosphere on Earth, on Jupiter deep convection equilibrates heat. The convection in the Jovian interior is thought to be driven mainly by the internal heat.Ingersoll (2004), pp.
In 2002 and 2019, southern-hemisphere major warmings were observed. These events are not fully understood. At an initial time a blocking-type circulation pattern establishes in the troposphere. This blocking pattern causes Rossby waves with zonal wavenumber 1 and/or 2 to grow to unusually large amplitudes.
The Rossby waves are themselves a different wind speed from what we experience in the lower troposphere. Local weather conditions play a key role in influencing wind speed, as the formation of hurricanes, monsoons and cyclones as freak weather conditions can drastically affect the flow velocity of the wind.
He is the PI of The DOMinica EXperiment,The DOMinica EXperiment a project to measure orographic precipitation in the tropics. He is also the PI of the DEEPWAVE Project,DEEPWAVE Project which studies gravity waves generated in the troposphere that propagate upwards to the mesophere near New Zealand.
The temperature of the troposphere decreases with altitude. And, saturation vapor pressure decreases strongly as temperature drops. Hence, the amount of water vapor that can exist in the atmosphere decreases strongly with altitude and the proportion of water vapor is normally greatest near the surface of the Earth.
The troposphere is the lowest layer of the Earth's atmosphere; it is located right above the planetary boundary layer, and is the layer in which most weather phenomena take place. The troposphere contains the boundary layer, and ranges in height from an average of at the poles, to at the Equator. In the absence of inversions and not considering moisture, the temperature lapse rate for this layer is 6.5 °C per kilometer, on average, according to the U.S. Standard Atmosphere. A measurement of both the tropospheric and the stratospheric lapse rates helps identifying the location of the tropopause, since temperature increases with height in the stratosphere, and hence the lapse rate becomes negative.
A hurricane functions as a Carnot heat engine powered by the temperature difference between the sea and the uppermost layer of the troposphere. As air is drawn in towards the eye it acquires latent heat from evaporating sea-water, which is then released as sensible heat during the rise inside the eyewall and radiated away at the top of the storm system. The energy input is balanced by energy dissipation in a turbulent boundary layer close to the surface, which leads to an energy balance equilibrium. However, in Emanuel's model, if the temperature difference between the sea and the top of the troposphere is too large, there is no solution to the equilibrium equation.
Expanding this atmospheric source of iron could complement ship-based deployment. One proposal is to boost the atmospheric iron level with Iron salt aerosol. Iron(III) chloride added to the troposphere could increase natural cooling effects including methane removal, cloud brightening and ocean fertilization, helping to prevent or reverse global warming.
Golden Gate Bridge in fog High- pressure systems are frequently associated with light winds at the surface and subsidence through the lower portion of the troposphere. Subsidence will generally dry out an air mass by adiabatic, or compressional, heating.Office of the Federal Coordinator for Meteorology (2006). Appendix G: Glossary. NOAA.
The very high temperatures generated by lightning lead to significant local increases in ozone and oxides of nitrogen. Each lightning flash in temperate and sub-tropical areas produces 7 kg of NOx on average. In the troposphere the effect of lightning can increase NOx by 90% and ozone by 30%.
Erik Anton Björkdal was a Swedish meteorologist who studied at the Bergen School of Meteorology where the theory of fronts was developed. His contribution was mainly in the field of dynamic meteorology. Among his works, mention must be made of the correlation between the tropopause geopotential and the troposphere temperature.
Lelieveld, J. and J. Heintzenberg (1992) Sulfate cooling effect on climate through in-cloud oxidation of SO2. Science 258, 117-120, doi:10.1126/science.258.5079.117.Lelieveld, J. and P.J. Crutzen (1994) Role of deep cloud convection in the ozone budget of the troposphere. Science 264, 1759-1761, doi:10.1126/science.264.5166.1759.
Earth's atmosphere has no definite boundary, slowly becoming thinner and fading into outer space. Three-quarters of the atmosphere's mass is contained within the first of the surface. This lowest layer is called the troposphere. Energy from the Sun heats this layer, and the surface below, causing expansion of the air.
The Measurements of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation (MAESTRO) instrument aboard SCISAT-1 measures the vertical distribution of ozone, nitrogen dioxide, water vapour, and aerosols in the Earth's atmosphere. MAESTRO consists of a UV-VIS-NIR spectrophotometer that measures the 285-1030 nm spectral region.
Prof. Maître's research advanced in the fields ranging from digital camera to computational photography. He has done extensive research in remote sensing applications. His work included studies related to troposphere effects and its multi-temporal correction in differential SAR interferometry, watermarking, feature detection of SAR images and Hough Transform applications.
In fact, the troposphere over the Antarctic plateau is nearly isothermal. Both observations and calculations show a slight "negative greenhouse effect" – more radiation emitted from the TOA than the surface. Although records are limited, the central Antarctic Plateau has seen little or no warming.See the first paragraph of Schmithüsen (2015).
Conventional weather is limited to the troposphere, and crosswinds are much gentler at 40,000 feet. Thus the Pegasus is largely immune to weather-induced delays and their associated costs, once at altitude. (Bad weather is still a factor during takeoff, ascent, and the transit to the staging point). Air launching reduces range costs.
Schematic showing the different layers of the atmosphere (not to scale). The tropopause is located between the troposphere and the stratosphere. The tropopause lies higher in the tropics than at the poles. Going upward from the surface, it is the point where air ceases to cool with height, and becomes almost completely dry.
330x330px The NIWA Lauder Atmospheric Research Laboratory takes atmospheric measurements for the purpose of observing and better understanding interactions between the stratosphere, troposphere and global climate. This is achieved through measurements of ozone, solar radiation, aerosols and greenhouse gases. There are approximately 10 staff (scientists and technicians) working at the Laboratory (December 2015).
2005 Tropical Eastern North Pacific Hurricane Outlook. Retrieved on 2006-05-02. They also carry heat and energy away from the tropics and transport it toward temperate latitudes, which makes them an important part of the global atmospheric circulation mechanism. As a result, tropical cyclones help to maintain equilibrium in the Earth's troposphere.
An iberulite is a co-association with axial geometry, consisting of well-defined mineral grains, together with non-crystalline compounds, structured around a coarse-grained core with a smectite rind, only one vortex and pinkish color, formed in the troposphere by complex aerosol-water-gas interactions. Aspect of several iberulites under optical microscope.
Air currents are concentrated areas of winds. They are mainly due to differences in pressure or temperature. They are divided into horizontal and vertical currents; both are present at mesoscale while horizontal ones dominate at synoptic scale. Air currents are not only found in the troposphere, but extend to the stratosphere and mesosphere.
The surprise severe weather event that occurred in Illinois and Indiana on April 20, 2004 is a good example. Importantly in that case, was that although overall CAPE was weak, there was strong CAPE in the lowest levels of the troposphere which enabled an outbreak of minisupercells producing large, long-track, intense tornadoes.
General circulation models and basic physical considerations predict that in the tropics the temperature of the troposphere should increase more rapidly than the temperature of the surface. A 2006 report to the U.S. Climate Change Science Program noted that models and observations agreed on this amplification for monthly and interannual time scales but not for decadal time scales in most observed data sets. Improved measurement and analysis techniques have reconciled this discrepancy: corrected buoy and satellite surface temperatures are slightly cooler and corrected satellite and radiosonde measurements of the tropical troposphere are slightly warmer. Satellite temperature measurements show that tropospheric temperatures are increasing with "rates similar to those of the surface temperature", leading the IPCC to conclude that this discrepancy is reconciled.
The reflection and refraction in the troposphere determines who hears the strike and who doesn't. Usually, the troposphere will reflect the light, and leave out the sound - in these cases some fraction of the light emanating from distant thunderstorms (whose distant clouds may be so low to the horizon as to be essentially invisible) is scattered by the upper atmosphere and thus visible to remote observers. Under optimum conditions, the most intense thunderstorms can be seen at up to over flat terrain or water when the clouds are illuminated by large lightning discharges. However, an upper limit of is more common due to topography, trees on the horizon, low to mid-level clouds, and the fact that local visibilities are generally no more than .
Further investigations confirmed that the volcano had clearly enhanced the convective environment, causing thunderstorms to form on average earlier in the day and more reliably than in surrounding areas, and that the presence of volcanic ash in cloud tops in the upper troposphere could be inferred from satellite imagery in at least one case.
There are also high-altitude cloud bands that wrap around the planet at constant latitude. These circumferential bands have widths of 50–150 km and lie about 50–110 km above the cloud deck. These altitudes are in the layer where weather occurs, the troposphere. Weather does not occur in the higher stratosphere or thermosphere.
Ingersoll (2004), pp. 5–7 The upper troposphere is colder in zones and warmer in belts. The exact nature of chemicals that make Jovian zones and bands so colorful is not known, but they may include complicated compounds of sulfur, phosphorus and carbon. The Jovian bands are bounded by zonal atmospheric flows (winds), called jets.
A NASA Global Hawk detects a hot tower measuring over 12 kilometers high within the eyewall of Hurricane Karl on September 16, 2010.Hurricane Bonnie. Altitudes of clouds are exaggerated. A hot tower is a tropical cumulonimbus cloud that reaches out of the lowest layer of the atmosphere, the troposphere, and into the stratosphere.
Nitrogen has two stable isotopes, 14N and 15N. The ratio between these is measured relative to nitrogen in ambient air. Nitrogen ratios are frequently linked to agricultural activities. Nitrogen isotope data has also been used to measure the amount of exchange of air between the stratosphere and troposphere using data from the greenhouse gas N2O.
Atmospheric Chemistry and Physics 16, 12477-12493, doi:10.5194/acp-16-12477-2016. To study the interplay between atmospheric composition and climate, Lelieveld introduced the dynamic coupling of atmospheric chemistry in general circulation models.Roelofs, G.-J. and J. Lelieveld (1995) Distribution and budget of O3 in the troposphere calculated with a chemistry-general circulation model.
Golden Gate Bridge in fog High-pressure systems are frequently associated with light winds at the surface and subsidence of air from higher portions of the troposphere. Subsidence will generally warm an air mass by adiabatic (compressional) heating.Office of the Federal Coordinator for Meteorology (2006). Appendix G: Glossary . NOAA. Retrieved on 2009-02-16.
Syed Iqbal Hasnain is an Indian glaciologist, writer, educationist and the Chairman of the Glacier and Climate Change Commission of the Government of Sikkim. He is a former vice chancellor of the University of Calicut and a member of the United Nations Environment Program Committee on Global Assessment of Black Carbon and Troposphere Ozone.
2011 carbon dioxide mole fraction in the troposphere. The atmosphere is one of the Earth's major carbon reservoirs and an important component of the global carbon cycle, holding approximately 720 gigatons of carbon. Atmospheric carbon plays an important role in the greenhouse effect. The most important carbon compound in this respect is the gas carbon dioxide ().
It incorporates all of the troposphere, stratosphere, mesosphere, and the lower part of the thermosphere. Chemically the homosphere is composed of 78% nitrogen, 21% oxygen, and trace amounts of other molecules, such as argon and carbon dioxide. It contains over 99% of the mass of the Earth's atmosphere. The density of air decreases with height in the homosphere.
Nimbostratus (V-60) with virga Abbreviation: Ns (V-60) Clouds of the genus nimbostratus tend to bring constant precipitation and low visibility. This cloud type normally forms above from altostratus cloud but tends to thicken into the lower levels during the occurrence of precipitation. The top of a nimbostratus deck is usually in the middle level of the troposphere.
Scientific investigation for the IAP is defined by the vertical extent of the atmosphere. Types of investigations include theoretical models, numerical simulation, and experiment for the Earth's boundary layer, troposphere, middle atmosphere, ionosphere and magnetosphere. The main research topic areas currently include mesoscale, dynamical, and applied meteorology. Furthermore, the processes of the atmospheric boundary layer are also of interest.
Jupiter's troposphere contains a complicated cloud structure. The upper clouds, located in the pressure range 0.6–0.9 bar, are made of ammonia ice. Below these ammonia ice clouds, denser clouds made of ammonium hydrosulfide ((NH4)SH) or ammonium sulfide ((NH4)2S, between 1–2 bar) and water (3–7 bar) are thought to exist.West et al.
Cumuliform clouds generally appear in isolated heaps or tufts. They are the product of localized but generally free-convective lift where no inversion layers are in the troposphere to limit vertical growth. In general, small cumuliform clouds tend to indicate comparatively weak instability. Larger cumuliform types are a sign of greater atmospheric instability and convective activity.
In 1956, Norman Phillips developed a mathematical model that could realistically depict monthly and seasonal patterns in the troposphere. It became the first successful climate model. Following Phillips's work, several groups began working to create GCMs. The first to combine both oceanic and atmospheric processes was developed in the late 1960s at the NOAA Geophysical Fluid Dynamics Laboratory.
The movement of sound in the atmosphere depends on the properties of the air, such as temperature and density. Because temperature and density change with height, the sound of thunder is refracted through the troposphere. This refraction results in spaces through which the thunder does not propagate. The sound of thunder often reflects off the Earth's surface.
Lenticular cloud over the Antarctic ice near Scott Base. Lenticular clouds (Latin: Lenticularis lentil-shaped, from lenticula lentil) are stationary clouds that form mostly in the troposphere, typically in perpendicular alignment to the wind direction. They are often comparable in appearance to a lens or saucer. Nacreous clouds that form in the lower stratosphere sometimes have lenticular shapes.
The grid used for global models is geodesic or icosahedral, spaced by latitude, longitude, and elevation. The data are then used in the model as the starting point for a forecast. A variety of methods are used to gather observational data for use in numerical models. Sites launch radiosondes, which rise through the troposphere and well into the stratosphere.
By volume, dry air contains 78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases. Air also contains a variable amount of water vapor. Except for the water vapor content, the composition of the troposphere is essentially uniform. The source of water vapor is at the Earth's surface through the process of evaporation.
The primary factor is convective depth. This is the vertical depth in the troposphere that a parcel of air will rise from the ground before it reaches the equilibrium (EQL) level and stops rising. A minimum depth of is necessary, and an average depth of or more is generally accepted as sufficient. Wind shear is also a significant factor.
The stratosphere is a region of intense interactions among radiative, dynamical, and chemical processes, in which the horizontal mixing of gaseous components proceeds much more rapidly than does vertical mixing. The overall circulation of the stratosphere is termed as Brewer-Dobson circulation, which is a single celled circulation, spanning from the tropics up to the poles, consisting of the tropical upwelling of air from the tropical troposphere and the extra-tropical downwelling of air. Stratospheric circulation is a predominantly wave-driven circulation in that the tropical upwelling is induced by the wave force by the westward propagating Rossby waves, in a phenomenon called Rossby-wave pumping. An interesting feature of stratospheric circulation is the quasi-biennial oscillation (QBO) in the tropical latitudes, which is driven by gravity waves that are convectively generated in the troposphere.
The chlorine-containing molecules also react with nitrogen monoxide (NO) to produce ozone. In a 2010 paper, Finlayson-Pitts detailed the role of halogens in reactions of the lower atmosphere. She found that chlorine ions in the air help ozone formation, while bromine ions aide ozone destruction. Both ions are common in the troposphere due to cycles between seawater and gaseous phases.
Deep convection (heat transfer) to the troposphere is enhanced over very warm sea surfaces in the tropics, such as during El Niño events. This tropical forcing generates atmospheric Rossby waves that have a poleward and eastward migration. Poleward-propagating Rossby waves explain many of the observed statistical connections between low- and high-latitude climates. One such phenomenon is sudden stratospheric warming.
Global ocean heat content in the top 700 m of the ocean. The factors that determine tropical cyclone activity are relatively well understood: warmer sea levels are favourable to tropical cyclones, as well as an unstable and moist mid-troposphere, while vertical wind shear suppresses them. All of these factors will change under global warming, but is often not clear which factor dominates.
Consequently, it is assumed that there are no anthropic clouds of these two genera. However, what can occur is enhancing existing Nimbostratus or Altostratus due to the additional water vapor or condensation nuclei emitted by a thermal power plant, for instance. The only anthropic clouds existing in the middle region of the troposphere are Altocumulus homogenitus (Aca) from contrails at this region.
The Uranian atmosphere can be divided into three layers: the troposphere, between altitudes of and pressures from 100 to 0.1 bar (10 MPa to 10 kPa); the stratosphere, spanning altitudes between and pressures of between (10 kPa to 10 µPa); and the thermosphere extending from 4,000 km to as high as 50,000 km from the surface. There is no mesosphere.
Some of the processes driving this uniformity include heating convection and air flow patterns. In the troposphere, rising warm air replaces higher cooler air which mix gases vertically. Wind patterns push air across the surface mixing it horizontally. At higher altitudes, other atmospheric circulation regimes exist, such as the Brewer-Dobson circulation in the terrestrial stratosphere, which mixes the air.
MOPITT 2000 global carbon monoxide. MOPITT (Measurements of Pollution in the Troposphere) is a payload scientific instrument launched into Earth orbit by NASA on board the Terra satellite in 1999. It is designed to monitor changes in pollution patterns and its effect in the lower atmosphere of the Earth. The instrument was funded by the Space Science Division of the Canadian Space Agency.
Satellite image of a high-pressure area south of Australia, evidenced by the clearing in the clouds High-pressure systems are frequently associated with light winds at the surface and subsidence through the lower portion of the troposphere. In general, subsidence will dry out an air mass by adiabatic or compressional heating.Office of the Federal Coordinator for Metmmmeorology (2006). Appendix G: Glossary. NOAA.
In the tropics, the border between the troposphere and stratosphere, the tropopause, typically lies at least above sea level. These formations are called "hot" because of the large amount of latent heat released as water vapor condenses into liquid and freezes into ice. The presence of hot towers within the eyewall of a tropical cyclone can indicate possible future strengthening.
Jöckel, P. et al., (2006) The atmospheric chemistry general circulation model ECHAM5/MESSy: Consistent simulation of ozone from the surface to the mesosphere. Atmospheric Chemistry and Physics 6, 5067-5104, doi:10.5194/acp-6-5067-2006. He showed that the increase of methane not only directly causes climate warming, but also indirectly through chemical reactions in the troposphere and stratosphere.
The cold claimed a further fourteen lives in Thailand, and snowstorms resulted in six deaths across Japan. This event was driven by a fast Arctic warming that occurred within the troposphere, forcing the Arctic Oscillation to change phase rapidly from positive (in late December) to negative (in late January), facilitating the atmospheric blocking and associated Siberian high buildup.Wang, S.-Y. S., Y.-H.
Polar cyclones are low-pressure zones embedded within the polar air masses, and exist year-round. The stratospheric polar vortex develops at latitudes above the subtropical jet stream. Horizontally, most polar vortices have a radius of less than . Since polar vortices exist from the stratosphere downward into the mid-troposphere, a variety of heights/pressure levels are used to mark its position.
Thus, T∞ varies between about 740 and 1350 K. During very quiet magnetospheric conditions, the still continuously flowing magnetospheric energy input contributes by about 250 K to the residual temperature of 500 K in eq.(2). The rest of 250 K in eq.(2) can be attributed to atmospheric waves generated within the troposphere and dissipated within the lower thermosphere.
However, at thermospheric altitudes, it becomes the predominant wave. It drives the electric Sq-current within the ionospheric dynamo region between about 100 and 200 km height. Heating, predominately by tidal waves, occurs mainly at lower and middle latitudes. The variability of this heating depends on the meteorological conditions within the troposphere and middle atmosphere, and may not exceed about 50%.
Nimbostratus has a diffuse cloud base generally found anywhere from near surface in the low levels to about in the middle level of the troposphere. Although usually dark at its base, it often appears illuminated from within to a surface observer. Nimbostratus usually has a thickness of about 2000 to 4000 m. Though found worldwide, nimbostratus occurs more commonly in the middle latitudes.
This view from orbit shows the full moon partially obscured by Earth's atmosphere. Above the troposphere, the atmosphere is usually divided into the stratosphere, mesosphere, and thermosphere. Each layer has a different lapse rate, defining the rate of change in temperature with height. Beyond these, the exosphere thins out into the magnetosphere, where the geomagnetic fields interact with the solar wind.
Retrieved on 2007-02-11.Myanmar government (2007). Haze. Retrieved on 2007-02-11. The air descending from the upper troposphere flows out from its center at surface level toward the upper and lower latitudes of each hemisphere, creating both the trade winds and the westerlies. It helps steer tropical cyclones and the monsoon.C.-P. Chang, Yongsheng Zhang, and Tim Li (1999).
One important example is NOx emissions into the stratosphere. The NOx reacts with both the atomic oxygen and ozone leading to a net decrease in ozone.This is particularly important at night when NO2 cannot photolyze. NO + O3 → NO2 \+ O2 NO2 \+ O(1D) → NO + O2 Net: O3 \+ O(1D) → 2O2 (net loss of ozone) Null cycles can also occur in the troposphere.
The ionosphere is a shell of electrons and electrically charged atoms and molecules that surrounds the Earth, stretching from a height of about to more than . It exists primarily due to ultraviolet radiation from the Sun. The lowest part of the Earth's atmosphere, the troposphere extends from the surface to about . Above that is the stratosphere, followed by the mesosphere.
The comprehensive and complex atmospheric measurements carried out during MOSAiC will provide a physical basis for understanding local and vertical interactions in the atmosphere and the interactions between the atmosphere, the sea ice and the ocean. The characterisation of processes in clouds, in the atmospheric boundary layer, surface layer and surface energy flux will lead to a better understanding of the lower troposphere, which interact with the surface in the Arctic. One of the greatest challenges will be taking carrying out these measurements consistently throughout the sea ice’s entire annual cycle, especially at the beginning of the freezing period, so as to monitor the transition from open water to a very thin ice layer. Readings taken at higher altitudes will provide insights into the characteristics of the middle and upper troposphere and the interaction with the stratosphere.
Chapter V, "The flow of steam through nozzles", pages 90 to 99 The study of supersaturation is also relevant to atmospheric studies. Since the 1940s, the presence of supersaturation in the atmosphere has been known. When water is supersaturated in the troposphere, the formation of ice lattices is frequently observed. In a state of saturation, the water particles will not form ice under tropospheric conditions.
The Tropomi instrument launched in year 2017 by the European Space Agency can measure methane, sulphur dioxide, nitrogen dioxide, carbon monoxide, aerosol, and ozone concentrations in earth's troposphere at resolutions of several kilometers. The CLAIRE satellite launched in year 2016 by the Canadian firm GHGSat can resolve carbon dioxide and methane to as little as 50 meters, thus enabling its customers to pinpoint the source of emissions.
The rate of microbiological activity slows during the last phase of waste decomposition as the supply of nutrients limits the chemical reactions, e.g. as bioavailable phosphorus becomes increasingly scarce. CH4 production almost completely disappears, with O2 and oxidized species gradually reappearing in the gas wells as O2 permeates downwardly from the troposphere. This transforms the oxidation–reduction potential (ORP) in the leachate toward oxidative processes.
During the years that followed, he named the two layers of the atmosphere known as the "troposphere" and the "stratosphere". This naming convention has since been maintained, with (higher-altitude) layers that were subsequently discovered being given names of this sort. After Teisserenc de Bort's death in 1913, the heirs donated the observatory to the state so that the research tasks could be continued.
A similar periodic variation, with maxima at the solstices, has been noted in microwave measurements of the deep troposphere begun in the 1960s. Stratospheric temperature measurements beginning in the 1970s also showed maximum values near the 1986 solstice. The majority of this variability is thought to occur owing to changes in the viewing geometry. There are some indications that physical seasonal changes are happening in Uranus.
Four images taken a few hours apart with the NASA/ESA Hubble Space Telescope Wide Field Camera 3 Neptune's more varied weather when compared to Uranus is due in part to its higher internal heating. The upper regions of Neptune's troposphere reach a low temperature of . At a depth where the atmospheric pressure equals , the temperature is . Deeper inside the layers of gas, the temperature rises steadily.
Recent studies have shown that the Atlantic portion of the WHWP (AWP) is significantly correlated with Atlantic hurricane activity. A large (or small) AWP reduces (or increases) the tropospheric vertical wind shear in the main development region for Atlantic hurricanes and increases (or decreases) the moist static instability of the troposphere, both of which favor (or don't favor) the intensification of tropical storms into major hurricanes.
They have wavelengths of thousands of kilometers and amplitudes in the tens of meters. ;Rossby Waves Rossby waves, or planetary waves are huge, slow waves generated in the troposphere by temperature differences between the ocean and the continents. Their major restoring force is the change in Coriolis force with latitude. Their wave amplitudes are usually in the tens of meters and very large wavelengths.
The TOR Station measures gas constituents in the atmosphere, including carbon dioxide, carbon monoxide, sulfur dioxide, ozone, nitrogen oxides, methane and hydrogen sulfide at two locations. The Siberian lidar station can measure the temperature in the stratosphere and troposphere. Aerosol particle size is measured by using six different wavelengths for the laser. The institute was founded in 1969 by Vladimir Yevseyevich Zuev who became its director.
Stratosphere-troposphere Processes and their Role in Climate (SPARC) is a core project of the World Climate Research Programme. Founded in 1992, SPARC has coordinated high-level research activities related to understanding Earth system processes for over two decades. More specifically, SPARC promotes and facilitates cutting-edge international research activities on how chemical and physical processes in the atmosphere interact with climate and climate change.
Unlike Earth's, Uranus's atmosphere has no mesosphere. The troposphere hosts four cloud layers: methane clouds at about 1.2 bar, hydrogen sulfide and ammonia clouds at 3–10 bar, ammonium hydrosulfide clouds at 20–40 bar, and finally water clouds below 50 bar. Only the upper two cloud layers have been observed directly—the deeper clouds remain speculative. Above the clouds lie several tenuous layers of photochemical haze.
The composition of the Uranian atmosphere is different from that of Uranus as a whole, consisting mainly of molecular hydrogen and helium. The helium molar fraction, i.e. the number of helium atoms per molecule of hydrogen/helium, was determined from the analysis of Voyager 2 far infrared and radio occultation observations. The currently accepted value is in the upper troposphere, which corresponds to a mass fraction .
Pluto has no or almost no troposphere; observations by New Horizons suggest only a thin tropospheric boundary layer. Its thickness in the place of measurement was 4 km, and the temperature was 37±3 K. The layer is not continuous. Above it lays a layer with fast increase of temperature with height, the stratosphere. The temperature gradient is estimated to be 2.2, or 5.5 degrees per km.
In it temperature decreases with height reaching a minimum of about 36 K at the tropopause. There is no stratosphere, defined as a layer where heating from the warmer troposphere and thermosphere is balanced by radiative cooling. Higher regions include the thermosphere (8–850 km) and exosphere (above 850 km). In the thermosphere the temperature rises reaching a constant value of about 95 K above 300 km.
The leading area of a squall line is composed primarily of multiple updrafts, or singular regions of an updraft, rising from ground level to the highest extensions of the troposphere, condensing water and building a dark, ominous cloud to one with a noticeable overshooting top and anvil (thanks to synoptic scale winds). Because of the chaotic nature of updrafts and downdrafts, pressure perturbations are important.
The bases of the two polar vortices are located in the middle and upper troposphere and extend into the stratosphere. Beneath that lies a large mass of cold, dense Arctic air. The interface between the cold dry air mass of the pole and the warm moist air mass farther south defines the location of the polar front. The polar front is centered, roughly at 60° latitude.
The weakening or strengthening of the polar vortex can alter the sea circulation more than a mile beneath the waves. Strengthening storm systems within the troposphere that cool the poles, intensify the polar vortex. La Niña–related climate anomalies significantly strengthen the polar vortex. Intensification of the polar vortex produces changes in relative humidity as downward intrusions of dry, stratospheric air enter the vortex core.
The lower atmosphere also typically contains a boundary between two distinct regions (the troposphere and stratosphere), but that boundary (the tropopause) displays quite different behavior. However, atmospheric thermoclines, or inversions, can occur, e.g. as nighttime cooling of the Earth's surface produces cold, dense, often calm air adjacent to the ground. The coldest air is next to the ground, with air temperature increasing with height.
Cumulus clouds in May Terrestrial clouds can be found throughout most of the homosphere, which includes the troposphere, stratosphere, and mesosphere. Within these layers of the atmosphere, air can become saturated as a result of being cooled to its dew point or by having moisture added from an adjacent source. In the latter case, saturation occurs when the dew point is raised to the ambient air temperature.
In addition to how clouds themselves will respond to increased temperatures, other feedbacks affect clouds properties and formation. The amount and vertical distribution of water vapor is closely linked to the formation of clouds. Ice crystals have been shown to largely influence the amount of water vapor. Water vapor in the subtropical upper troposphere has been linked to the convection of water vapor and ice.
Cloudbase is the fictional skyborne headquarters of the international security organisation Spectrum from Gerry Anderson's science-fiction television series Captain Scarlet and the Mysterons (1967–68). In the 2005 computer-animated remake, Cloudbase is re-imagined as Skybase. In both series, the base's design is that of an airborne aircraft carrier, stationed in either Earth's high troposphere (in the original series) or low stratosphere (in the remake).
Her lab currently works on modeling the stability of this radical and its conformers. Currently, her group focuses on photo-induced chemistry of Criegee intermediates, an intermediate in the alkene ozonolysis pathway. This pathway is a primary oxidation pathway for alkenes in the troposphere and generates atmospheric hydroxyl radicals. Her lab synthesizes Criegee intermediates in order to further study their chemical reactions using spectroscopy.
As an average, the International Civil Aviation Organization (ICAO) defines an international standard atmosphere (ISA) with a temperature lapse rate of 6.49 °C per kilometer (3.56 °F per 1,000 feet). The actual lapse rate can vary by altitude and by location. Finally, note that only the troposphere (up to approximately of altitude) in the Earth's atmosphere undergoes notable convection; in the stratosphere, there is little vertical convection.
The combination of these chemicals in the presence of sunlight form ozone. Its concentration increases as height above sea level increases, with a maximum concentration at the tropopause. About 90% of total ozone in the atmosphere is in the stratosphere, and 10% is in the troposphere. Although tropospheric ozone is less concentrated than stratospheric ozone, it is of concern because of its health effects.
The atmospheric temperature in the troposphere normally decreases by about 6-7 K/km, but small changes in this gradient can have a large effect on the final column height. Theoretically, the maximum achievable column height is thought to be about . In practice, column heights ranging from about are seen. Eruption columns with heights of over break through the tropopause and inject particulates into the stratosphere.
Ahmed Zewail, won the 1999 Nobel Prize in chemistry for his work in femtochemistry, methods that allow the description of change states in femtoseconds or very short seconds. The Democratic Republic of the Congo has a rocketry program called Troposphere. Currently, forty percent of African-born scientists live in OCED countries, predominantly NATO and EU countries. This has been described as an African brain drain.
Aurora australis in the Earth's atmosphere observed by Space Shuttle Discovery, May 1991 Space weather is the environmental condition within the Solar System, including the solar wind. It is studied especially surrounding the Earth, including conditions from the magnetosphere to the ionosphere and thermosphere. Space weather is distinct from terrestrial weather of the troposphere and stratosphere. The term was not used until the 1990s.
Numerous paleoenvironmental reconstructions have looked for relationships between solar variability and climate. Arctic paleoclimate, in particular, has linked total solar irradiance variations and climate variability. A 2001 paper identified a ~1500 year solar cycle that was a significant influence on North Atlantic climate throughout the Holocene. Models and observations show that greenhouse gas results in warming of the troposphere, but cooling of the stratosphere.
In the atmosphere, emitted gases and particles may react further to form new chemical species. Some compounds may not react within the troposphere, but will break down and participate in further transformations in the higher stratosphere. The inorganic chemistry of oxides of nitrogen and sulfur in the gas phase are better understood than the interactions of nitrogen and sulfur oxides with organic compounds. Finlayson-Pitts and her colleagues have done important work on understanding the chemistry of the troposphere, in particular, the conversion of nitric oxide (NO) to nitrogen dioxide (NO2) in air and the subsequent formation of ozone, nitric acid, and organic nitrates. Finlayson-Pitts served as the lead author of a 2009 study published in the Proceedings of the National Academy of Sciences that found that burning fossil fuels releases nitrogen oxides, which interact with gaseous hydrogen chloride to form smog-forming compounds.
The hydroxyl •OH radical is one of the main chemical species controlling the oxidizing capacity of the global Earth atmosphere. This oxidizing reactive species has a major impact on the concentrations and distribution of greenhouse gases and pollutants in the Earth atmosphere. It is the most widespread oxidizer in the troposphere, the lowest part of the atmosphere. Understanding •OH variability is important to evaluating human impacts on the atmosphere and climate.
The intermediate layers of the troposphere are the regions with less influence of human activity. This region is far enough from the surface for not being affected by the surface emissions. Additionally, commercial and military flights only cross this region during ascending or descending maneuvers. Moreover, in this region there exist two types of clouds with a large horizontal extension: Nimbostratus and Altostratus, which cannot originate from human activity.
More formally, the tropopause is the region of the atmosphere where the environmental lapse rate changes from positive, as it behaves in the troposphere, to the stratospheric negative one. Following is the exact definition used by the World Meteorological Organization: The tropopause as defined above renders as a first-order discontinuity surface, that is, temperature as a function of height varies continuously through the atmosphere but the temperature gradient does not.
The composition of Uranus's atmosphere is different from its bulk, consisting mainly of molecular hydrogen and helium. The helium molar fraction, i.e. the number of helium atoms per molecule of gas, is in the upper troposphere, which corresponds to a mass fraction . This value is close to the protosolar helium mass fraction of , indicating that helium has not settled in its centre as it has in the gas giants.
Wind shear must be low; when wind shear is high, the convection and circulation in the cyclone will be disrupted. Usually, an anticyclone in the upper layers of the troposphere above the storm must be present as well—for extremely low surface pressures to develop, air must be rising very rapidly in the eyewall of the storm, and an upper-level anticyclone helps channel this air away from the cyclone efficiently.
For tropical transitioning cyclones (i.e. Hurricane Ophelia (2017)) a water temperature of at least has been suggested. Another factor is rapid cooling with height, which allows the release of the heat of condensation that powers a tropical cyclone. High humidity is needed, especially in the lower-to-mid troposphere; when there is a great deal of moisture in the atmosphere, conditions are more favorable for disturbances to develop.
Discussion of the layers in the Earth's atmosphere is needed to understand where airborne pollutants disperse in the atmosphere. The layer closest to the Earth's surface is known as the troposphere. It extends from sea-level to a height of about 18 km and contains about 80 percent of the mass of the overall atmosphere. The stratosphere is the next layer and extends from 18 km to about 50 km.
These storms normally have such powerful updrafts that the top of the supercell storm cloud (or anvil) can break through the troposphere and reach into the lower levels of the stratosphere. Supercell storms can be wide. Research has shown that at least 90 percent of supercells cause severe weather. These storms can produce destructive tornadoes, extremely large hailstones ( diameter), straight-line winds in excess of , and flash floods.
With no oxygen, methane stayed in the atmosphere longer and at higher concentrations than it does today. The known sources of methane are predominantly located near the Earth's surface. In combination with vertical atmospheric motions and methane's relatively long lifetime, methane is considered to be a well-mixed gas. In other words, the concentration of methane is taken to be constant with respect to height within the troposphere.
The dew point depression (T-Td) is the difference between the temperature and dew point temperature at a certain height in the atmosphere. For a constant temperature, the smaller the difference, the more moisture there is, and the higher the relative humidity. In the lower troposphere, more moisture (small dew point depression) results in lower cloud bases and lifted condensation levels (LCL). LCL height is an important factor modulating severe thunderstorms.
Aircraft flying at high altitude form condensation trails or contrails in the exhaust plume of their engines. While in the Troposphere these have very little climatic impact. However, jet aircraft cruising in the Stratosphere do create an impact from their contrails, although the extent of the damage to the environment is as yet unknown. Contrails can also trigger the formation of high-altitude Cirrus cloud thus creating a greater climatic effect.
The subtropical ridge shows up as a large area of black (dryness) on this water vapor satellite image from September 2000 Highs are frequently associated with light winds at the surface and subsidence through the lower portion of the troposphere. In general, subsidence will dry out an air mass by adiabatic, or compressional, heating.Office of the Federal Coordinator for Meteorology (2006). Appendix G: Glossary. NOAA. Retrieved on 2009-02-16.
At first they thought it was a Soviet weather rocket on its way to the troposphere, but when it had reached the cruising altitude of the aircraft, it turned and came straight at it. Then the rocket exploded. It was clear to the pilots that the rocket had been locked to its target, the Finnair aircraft. The inertial navigation system equipment of the aircraft allowed the crew to determine their position.
The tracking of numerous cloud features allowed determination of zonal winds blowing in the upper troposphere of Uranus. At the equator winds are retrograde, which means that they blow in the reverse direction to the planetary rotation. Their speeds are from −100 to −50 m/s. Wind speeds increase with the distance from the equator, reaching zero values near ±20° latitude, where the troposphere's temperature minimum is located.
The mechanism of physical changes is still not clear. Near the summer and winter solstices, Uranus's hemispheres lie alternately either in full glare of the Sun's rays or facing deep space. The brightening of the sunlit hemisphere is thought to result from the local thickening of the methane clouds and haze layers located in the troposphere. The bright collar at −45° latitude is also connected with methane clouds.
By the top of the troposphere, about 12 km above sea level, most water vapor condenses to liquid water or ice as it releases its heat of vapourization. Once changed state, liquid water and ice fall away to lower altitudes. This will be balanced by incoming water vapour rising via convection currents. Liquid water and ice emit radiation at a higher rate than water vapour (see graph above).
These satellites are able to detect the concentration of water in the troposphere at altitudes between 4 and 12 kilometres. Satellites that can measure water vapor have sensors that are sensitive to infrared radiation. Water vapor specifically absorbs and re- radiates radiation in this spectral band. Satellite water vapor imagery plays an important role in monitoring climate conditions (like the formation of thunderstorms) and in the development of weather forecasts.
Usually, within the lower atmosphere (the troposphere) the air near the surface of the Earth is warmer than the air above it, largely because the atmosphere is heated from below as solar radiation warms the Earth's surface, which in turn then warms the layer of the atmosphere directly above it, e.g., by thermals (convective heat transfer).Nagle, Garrett, and Paul Guinness. Cambridge International A and AS Level Geography.
It is vital to wind speed, because the greater the difference in pressure, the faster the wind flows (from the high to low pressure) to balance out the variation. The pressure gradient, when combined with the Coriolis effect and friction, also influences wind direction. Rossby waves are strong winds in the upper troposphere. These operate on a global scale and move from West to East (hence being known as Westerlies).
When Burns made the song, he wanted to "write a positive, empowering, exclamation point of a song". The song itself contains a "fury of noise". The following track, "What I Do on Saturday", is a "playful" pop song, while "Maintain" is a more mainstream song influenced by American alternative band They Might Be Giants. The song "Troposphere" is "bright and bouncy", sounding like the Flaming Lips song "Fight Test".
In 1956, Norman Phillips developed a mathematical model that realistically depicted monthly and seasonal patterns in the troposphere. This was the first successful climate model. Several groups then began working to create general circulation models. The first general circulation climate model combined oceanic and atmospheric processes and was developed in the late 1960s at the Geophysical Fluid Dynamics Laboratory, a component of the U.S. National Oceanic and Atmospheric Administration.
Flights took place at both high-altitudes and low-altitudes to measure aerosol heights and aerosol/ecosystem spatial features. High-altitude flights collected data on above-cloud aerosols and atmospheric measurements of background aerosols in the troposphere. Once above the ship, the airplane underwent spiral descents to low-altitude to acquire data on the vertical structure of aerosols. These low-altitude flights sampled aerosols within the marine boundary layer.
The downward-moving exterior is caused by colder air being displaced at the top of the thermal. The size and strength of thermals are influenced by the properties of the lower atmosphere (the troposphere). Generally, when the air is cold, bubbles of warm air are formed by the ground heating the air above it and can rise like a hot air balloon. The air is then referred to as unstable.
One example is the null cycle that occurs during the day between NOx and ozone. Tropospheric Null Cycle O3 \+ NO → O2 \+ NO2 NO2 \+ hν → NO + O(3P) O (3P) + O2 \+ M → O3 \+ M Net: hv → H This cycle links ozone to NOx in the troposphere during daytime. In equilibrium, described by the Leighton relationship, solar radiation and the NO2:NO ratio determine ozone abundance, maximizing around noon time.
Wind shear is a difference in relative speed between two adjacent air masses. An excessive wind shear produces vortices, and when the wind shear is of sufficient degree, the air will tend to move chaotically. As is explained elsewhere in this article, temperature decreases and wind velocity increase with height in the troposphere, and the reverse is true within the stratosphere. These differences cause changes in air density, and hence viscosity.
The high étage ranges from altitudes of in the polar regions, in the temperate regions and in the tropical region. The major high-level cloud types comprise cirrus, cirrocumulus, and cirrostratus. The middle étage extends from above surface at any latitude as high as near the poles, at mid latitudes, and in the tropics. Altocumulus and Altostratus are the main cloud types found in the middle levels of the troposphere.
More general airmass instability in the troposphere tends to produce clouds of the more freely convective cumulus genus type, whose species are mainly indicators of degrees of atmospheric instability and resultant vertical development of the clouds. A cumulus cloud initially forms in the low level of the troposphere as a cloudlet of the species humilis that shows only slight vertical development. If the air becomes more unstable, the cloud tends to grow vertically into the species mediocris, then strongly convective congestus, the tallest cumulus species which is the same type that the International Civil Aviation Organization refers to as 'towering cumulus'. With highly unstable atmospheric conditions, large cumulus may continue to grow into even more strongly convective cumulonimbus calvus (essentially a very tall congestus cloud that produces thunder), then ultimately into the species capillatus when supercooled water droplets at the top of the cloud turn into ice crystals giving it a cirriform appearance.
Clouds associated with the meiyu during the 2016 Jiangsu tornado The meiyu front, also known as baiu front, is a persistent nearly stationary weak baroclinic zone in the lower troposphere. It is located over the east coast of China and Taiwan at its western end, and over the Pacific Ocean south of Japan at its eastern end. The term meiyu (mei-yu) is Chinese for "plum rains", pronounced baiu (bai-u) in Japanese ().
This leads to at least some degree of adiabatic warming of the air which can result in the cloud droplets or crystals turning back into invisible water vapor. Stronger forces such as wind shear and downdrafts can impact a cloud, but these are largely confined to the troposphere where nearly all the Earth's weather takes place. A typical cumulus cloud weighs about 500 metric tons, or 1.1 million pounds, the weight of 100 elephants.
Some people thought that the ozone hole should be above the sources of CFCs. However, CFCs are well mixed globally in the troposphere and stratosphere. The reason for occurrence of the ozone hole above Antarctica is not because there are more CFCs concentrated but because the low temperatures help form polar stratospheric clouds. In fact, there are findings of significant and localized "ozone holes" above other parts of the earth, like above Central Asia.
A haze permeates most of Triton's troposphere, thought to be composed largely of hydrocarbons and nitriles created by the action of sunlight on methane. Triton's atmosphere also has clouds of condensed nitrogen that lie between 1 and 3 km from its surface. In 1997, observations from Earth were made of Triton's limb as it passed in front of stars. These observations indicated the presence of a denser atmosphere than was deduced from Voyager 2 data.
Diagram of a Northern hemisphere hurricane Tropical cyclones are areas of relatively low pressure in the troposphere, with the largest pressure perturbations occurring at low altitudes near the surface. On Earth, the pressures recorded at the centers of tropical cyclones are among the lowest ever observed at sea level. The environment near the center of tropical cyclones is warmer than the surroundings at all altitudes, thus they are characterized as "warm core" systems.
The thermosphere gradually transitions to the exosphere. Bands of high-altitude clouds cast shadows on Neptune's lower cloud deck Models suggest that Neptune's troposphere is banded by clouds of varying compositions depending on altitude. The upper-level clouds lie at pressures below one bar, where the temperature is suitable for methane to condense. For pressures between one and five bars (100 and 500 kPa), clouds of ammonia and hydrogen sulfide are thought to form.
The polar low is not driven by convection as are tropical cyclones, nor the cold and warm air mass interactions as are extratropical cyclones, but is an artifact of the global air movement of the Polar cell. The base of the polar low is in the mid to upper troposphere. In the Northern Hemisphere, the polar cyclone has two centers on average. One center lies near Baffin Island and the other over northeast Siberia.
Surface analysis indicated that the cyclone had multiple circulations, with a weaker cyclonic circulation persisting over the eastern shore of Lake Huron and another center north of Lake Ontario. During this 12-hour period, the cyclone decayed rapidly, mainly in the lower troposphere. Twelve-hour cloud height rises also occurred, ranging from 66–197 feet (20–60 m). On September 15, the cyclone weakened into a remnant low and left Lake Huron, dissipating soon afterward.
Altostratus translucidus (V-49) near top of photo merging into altostratus opacus (V-50) near bottom Abbreviation: As Stratiform clouds of the genus altostratus form when a large convectively stable airmass is lifted to condensation in the middle level of the troposphere, usually along a frontal system. Altostratus can bring light rain or snow. If the precipitation becomes continuous, it may thicken into nimbostratus which can bring precipitation of moderate to heavy intensity.
The slow-moving disturbance tracked towards the south and southeast, steered by a broad area of high pressure. On November 23, 01F attained tropical depression status. Supported by the stout outflow of air at the upper-levels of the troposphere, shower activity became more concentrated around the center of circulation. The depression reached tropical cyclone intensity by 06:00 UTC on November 24 near the Santa Cruz Islands, earning the name Rita.
Oxidation of methane is the main source of water vapor in the upper stratosphere (beginning at pressure levels around 10 kPa). The methyl radical formed in the above reaction will, during normal daytime conditions in the troposphere, usually react with another hydroxyl radical to form formaldehyde. Note that this is not strictly oxidative pyrolysis as described previously. Formaldehyde can react again with a hydroxyl radical to form carbon dioxide and more water vapor.
Within the entrainment zone, cleaner free troposphere eddies will mix with more polluted boundary layer eddies resulting in high variances at the height of the entrainment layer. The use of satellite derived boundary layer heights provides another method for verifying climate model output. Some remote sensing instruments have limitations. Since CALIOP relies on the use of backscattered light, daytime retrievals can contain high signal to noise ratios as sunlight can add background noise.
At 1800 UTC that day, the depression intensified to moderate tropical storm intensity, thus receiving the name Bejisa by the Mauritius Meteorological Services. This coincided with the improving satellite appearance of the storm's central dense overcast. Intensification subsequently quickened, and at 0600 UTC the next day Bejisa was considered to be a severe tropical storm. Concurrently a strengthening ridge in the mid-levels of the troposphere began to steer the storm towards the south-southeast.
The convective temperature (CT or Tc) is the approximate temperature that air near the surface must reach for cloud formation without mechanical lift. In such case, cloud base begins at the convective condensation level (CCL), whilst with mechanical lifting (such as from low-pressure areas located in the lower troposphere, frontal systems, surface boundaries, gravity waves, and convergence zones), condensation begins at the lifted condensation level (LCL). Convective temperature is important to forecasting thunderstorm development.
University of California Transportation Center, UC Berkeley. ; Nitrogen oxides (NOₓ) : In the tropopause, emissions of NOₓ favor ozone (O₃) formation in the upper troposphere. Altitudes from 8 to 13 km, NOₓ emissions result in greater concentrations of O₃ than surface NOₓ emissions, and these in turn have a greater global warming effect. The effect of O₃ surface concentrations are regional and local, but it becomes well mixed globally at mid and upper tropospheric levels.
Shortwave troughs embedded within the flow around larger scale troughs are smaller in scale, or mesoscale in nature. Both Rossby waves and shortwaves embedded within the flow around Rossby waves migrate equatorward of the polar cyclones located in both the Northern and Southern hemispheres. All share one important aspect, that of upward vertical motion within the troposphere. Such upward motions decrease the mass of local atmospheric columns of air, which lowers surface pressure.
Here air starts to descend and returns to the equator below the clouds. This interpretation is supported by the distribution of the carbon monoxide, which is also concentrated in the vicinity of ±60° latitudes. Poleward of the Hadley cell a different pattern of circulation is observed. In the latitude range 60°–70° cold polar collars exist. They are characterized by temperatures about 30–40 K lower than in the upper troposphere at nearby latitudes.
The main most important features in this region are strong zonal (East-West) winds, atmospheric tides, internal atmospheric gravity waves (commonly called "gravity waves"), and planetary waves. Most of these tides and waves start in the troposphere and lower stratosphere, and propagate to the mesosphere. In the mesosphere, gravity-wave amplitudes can become so large that the waves become unstable and dissipate. This dissipation deposits momentum into the mesosphere and largely drives global circulation.
Unlike the troposphere, where greenhouse gases result in the atmosphere heating up, increased CO2 in the mesosphere acts to cool the atmosphere due to increased radiative emission. This results in a measurable effect - the mesopause should become cooler with increased CO2. Observations do show a decrease of temperature of the mesopause, though the magnitude of this decrease varies and is subject to further study. Modeling studies of this phenomenon have also been carried out.
Clouds form when the dewpoint temperature of water is reached in the presence of condensation nuclei in the troposphere. The atmosphere is a dynamic system, and the local conditions of turbulence, uplift and other parameters give rise to many types of clouds. Various types of cloud occur frequently enough to have been categorized. Furthermore, some atmospheric processes can make the clouds organize in distinct patterns such as wave clouds or actinoform clouds.
Clumped isotope analyses have recently been used to constrain the paleoaltitude or uplift history of a region. Air temperature decreases systematically with altitude throughout the troposphere (see lapse rate). Due to the close coupling between lake water temperature and air temperature, there is a similar decrease in lake water temperature as altitude increases. Thus, variation in water temperature implied by Δ47 could indicate changes in lake altitude, driven by tectonic uplift or subsidence.
It exhibits a banded pattern similar to Jupiter's, and occasionally exhibits long-lived ovals caused by storms. A storm formation analogous to Jupiter's Great Red Spot, the Great White Spot, is a short-lived phenomenon that forms with a roughly 30-year periodicity. It was last observed in 1990. However, the storms and the band pattern are less visible and active than those of Jupiter, due to the overlying ammonia hazes in Saturn's troposphere.
After sufficient oxidation, the vapor pressure is sufficiently low that the gas-phase compound partitions into the solid-phase, producing secondary organic matter (the particle phase of secondary organic aerosol). SOAs represent a significant proportion of aerosols contained in the troposphere. A common misconception is that the aerosol refers to the solid phase of the compound, where in reality, by definition, it is the combination of the gas- and solid-phases which constitute the aerosol.
Volcanic activity such as at Jom-Bolok can cause the injection of into the atmosphere. When such gas reaches the stratosphere it can cause temperature anomalies named volcanic winters. In the case of the northern field of Jom-Bolok, the total amount of reaching the upper troposphere would be about if one assumes a similar eruption in style to the Laki eruptions, which however took place at latitudes with a lower stratosphere.
The ACE-FTS instrument is the main payload of the SCISAT-1 spacecraft. The primary scientific goal of the Atmospheric Chemistry Experiment (ACE) is to measure and understand the chemical and dynamical processes that control the distribution of ozone in the upper troposphere and stratosphere. The principle of ACE measurement is the solar occultation technique. A high inclination (74 degrees), low Earth orbit will provide ACE coverage of tropical, mid-latitudes and polar regions.
In meteorology, latent heat flux is the flux of energy from the Earth's surface to the atmosphere that is associated with evaporation or transpiration of water at the surface and subsequent condensation of water vapor in the troposphere. It is an important component of Earth's surface energy budget. Latent heat flux has been commonly measured with the Bowen ratio technique, or more recently since the mid-1900s by the eddy covariance method.
An idealised view of three pairs of large circulation cells. Atmospheric circulation is the large-scale movement of air through the troposphere, and the means (with ocean circulation) by which heat is distributed around Earth. The large-scale structure of the atmospheric circulation varies from year to year, but the basic structure remains fairly constant because it is determined by Earth's rotation rate and the difference in solar radiation between the equator and poles.
Use of the 300 and 200 hPa constant pressure charts can indicate the strength of systems in the lower troposphere, as stronger systems near the Earth's surface are reflected as stronger features at these levels of the atmosphere. Isotachs are drawn at these levels, which a lines of equal wind speed. They are helpful in finding maxima and minima in the wind pattern. Minima in the wind pattern aloft are favorable for tropical cyclogenesis.
The National Atmospheric Research Laboratory(NARL) is an autonomous Research Institute funded by the Department of Space of the Government of India. NARL is engaged in fundamental and applied research in the field of Atmospheric Sciences. The research institute was started in 1992 as National Mesosphere- Stratosphere-Troposphere (MST) Radar Facility (NMRF). Over the years many other facilities such as Mie/Rayleigh Lidar, Lower atmospheric wind profiler, optical rain gauge, disdrometer, automated weather stations etc.
Furthermore, the wind shear in the lower troposphere was creating a large helicity value conducive to a tornado potential. With the advancing cold front, two lines of thunderstorms developed. The first one was near Stratford, Ontario ( west of Kitchener), and spread as far north as Georgian Bay near Collingwood, Ontario while the second one was following behind near the shores of Lake Huron. They tracked eastward and reached as far as Oshawa during the afternoon.
Retrieved on 27 June 2008. On Earth, most weather phenomena occur in the lowest level of the planet's atmosphere, the troposphere,Glossary of Meteorology. Hydrosphere. Retrieved on 27 June 2008. just below the stratosphere. Weather refers to day- to-day temperature and precipitation activity, whereas climate is the term for the averaging of atmospheric conditions over longer periods of time. When used without qualification, "weather" is generally understood to mean the weather of Earth.
Troposphere is a Congolese rocket family first developed in 2007 at the private enterprise Développement Tous Azimuts (DTA). The project is managed by Jean-Patrice Keka Ohemba Okese, head of DTA, a graduate of the Institut Supérieur des Techniques Appliquées (ISTA). The program aimed at launching experimental rockets that would not exceed an altitude of 36 km. The launch site is located in an area owned by DTA at Menkao, 120 km East of Kinshasa.
The water and air are returned to the east. Both are now much cooler, and the air is much drier. An El Niño episode is characterised by a breakdown of this water and air cycle, resulting in relatively warm water and moist air in the eastern Pacific. The Walker circulation, also known as the Walker cell, is a conceptual model of the air flow in the tropics in the lower atmosphere (troposphere).
To compare to the trend from the surface temperature record (+0.1610.033 °C/decade from 1979 to 2012 according to NASA GISS) it is most appropriate to derive trends for the part of the atmosphere nearest the surface, i.e., the lower troposphere. Doing this, through December 2019, the UAH linear temperature trend 1979-2019 shows a warming of +0.13 °C/decade, For comparison, a different group, Remote Sensing Systems (RSS), also analyzes the MSU data.
A zonal flow regime. Note the dominant west-to-east flow as shown in the 500 hPa height pattern. Trend of the lower troposphere from 2004 A zonal flow regime is the meteorological term meaning that the general flow pattern is west to east along the Earth's latitude lines, with weak shortwaves embedded in the flow. The use of the word "zone" refers to the flow being along the Earth's latitudinal "zones".
The lifted index (LI), usually expressed in kelvins, is the temperature difference between the temperature of the environment Te(p) and an air parcel lifted adiabatically Tp(p) at a given pressure height in the troposphere, usually 500 hPa (mb). When the value is positive, the atmosphere (at the respective height) is stable and when the value is negative, the atmosphere is unstable. Thunderstorms are expected with values below −2, and severe weather is anticipated with values below −6.
Lauder's clear skies, low horizons, dry atmosphere, and southern latitude location make it an ideal site for atmospheric research. The NIWA atmospheric research laboratory takes atmospheric measurements for the purpose of observing and better understanding interactions between the stratosphere, troposphere and global climate. This is achieved through measurements of ozone, ozone depleting substances (ODS), solar radiation, aerosols and greenhouse gases. The clear night air around Lauder also makes the area popular with both amateur and professional astronomers.
For example, strontium-90 will have less time to condense and coalesce into larger particles, resulting in greater degree of mixing in the volume of air and smaller particles. The particles produced immediately after the burst are small, with 90% of the radioactivity present in particles smaller than 300 nanometers. These coagulate with stratospheric aerosols. Coagulation is more extensive in the troposphere, and, at ground level, most activity is present in particles between 300 nm and 1 µm.
They measure radiances in various wavelength bands. Since 1978 microwave sounding units (MSUs) on National Oceanic and Atmospheric Administration polar orbiting satellites have measured the intensity of upwelling microwave radiation from atmospheric oxygen, which is related to the temperature of broad vertical layers of the atmosphere. Measurements of infrared radiation pertaining to sea surface temperature have been collected since 1967. Satellite datasets show that over the past four decades the troposphere has warmed and the stratosphere has cooled.
Recent observation also discovered that cloud features on Uranus have a lot in common with those on Neptune. For example, the dark spots common on Neptune had never been observed on Uranus before 2006, when the first such feature dubbed Uranus Dark Spot was imaged. The speculation is that Uranus is becoming more Neptune-like during its equinoctial season. The tracking of numerous cloud features allowed determination of zonal winds blowing in the upper troposphere of Uranus.
Thor analyses red sprites, blue and gigantic jets from the Space Station over Earth at night. Sprites appear as luminous reddish-orange flashes and last 20 milliseconds at most. They often occur in clusters within atmosphere above the troposphere at an altitude range of 50–90 km (31–56 mi). They were first photographed on July 6, 1989 by scientists from the University of Minnesota and have subsequently been captured in video recordings many thousands of times.
The daytime increase of the PBL from up-slope winds is called mountain venting. This phenomenon can sometimes cause a vertical exchange of the PBL air into the free troposphere. Similarly to the daytime situation, during summer the top of the mountain is warmer than its surroundings creating a low pressure zone. Winds then blow up from the plains to the mountain top, which is an efficient lifting mechanism to carry PBL pollutants into the free atmosphere.
Computer generated Lifted Index field from April 6th, 2009, at 1 pm EDT. Unstable areas are in yellow (slightly) and red (highly) while the stable zone is in blue. The lifted index (LI) is the temperature difference between the environment Te(p) and an air parcel lifted adiabatically Tp(p) at a given pressure height in the troposphere (lowest layer where most weather occurs) of the atmosphere, usually 500 hPa (mb). The temperature is measured in Celsius.
An upper limit in the low 40s (K) can be set from vapor pressure equilibrium with nitrogen gas in Triton's atmosphere. The most likely temperature was as of 1989. In the 1990s it probably increased by about 1 K, due to the general global warming as Triton approaches the southern-hemisphere summer (see below). Convection near Triton's surface heated by the Sun creates a troposphere (a "weather region") rising to an altitude of about 8 km.
The Stratospheric Aerosol and Gas Experiment (SAGE) is a series of remote sensing satellite instruments used to study the chemical composition of earth's atmosphere. Specifically, SAGE has been used to study the Earth's ozone layer and aerosols at the troposphere through the stratosphere. The SAGE instruments use solar occultation measurement technique to determine chemical concentrations in the atmosphere. Solar occultation measurement technique measures sunlight through the atmosphere and ratios that measurement with a sunlight measurement without atmospheric attenuation.
The observations in the various infrared atmospheric windows indicate that the anticyclonic circulation observed near the poles penetrates as deep as to 50 km altitude, i.e. to the base of the clouds. The polar upper troposphere and mesosphere are extremely dynamic; large bright clouds may appear and disappear over the space of a few hours. One such event was observed by Venus Express between 9 and 13 January 2007, when the south polar region became brighter by 30%.
At the top of this nighttime boundary layer (which may be only a hundred meters) the normal adiabatic temperature profile of the troposphere (i.e. temperature decreasing with altitude) is again observed. The thermocline or inversion layer occurs where the temperature profile changes from positive to negative with increasing height. The stability of the night time inversion is usually destroyed soon after sunrise as the sun's energy warms the ground, which warms the air in the inversion layer.
Divergence is the opposite of convergence. In the Earth's troposphere, it involves the horizontal outflow of air from the upper part of a rising column of air, or from the lower part of a subsiding column often associated with an area or ridge of high pressure. Cloudiness tends to be least prevalent near the poles and in the subtropics close to the 30th parallels, north and south. The latter are sometimes referred to as the horse latitudes.
The organisation of the system's cloud pattern improved in response. At 18:00 UTC on 10 March, the system was redesignated as a tropical cyclone while located 370 km (230 mi) south-southwest of Honiara, Solomon Islands. A trough in the upper-troposphere caused the reformed Erica to accelerate towards the southeast. Erica's winds reached hurricane strength at 18:00 UTC on 11 March, classifying the cyclone as a Category 3 on the Australian and Fijian cyclone scale.
Many tropical cyclones develop when the atmospheric conditions around a weak disturbance in the atmosphere are favorable. Others form when other types of cyclones acquire tropical characteristics. Tropical systems are then moved by steering winds in the troposphere; if the conditions remain favorable, the tropical disturbance intensifies, and can even develop an eye. On the other end of the spectrum, if the conditions around the system deteriorate or the tropical cyclone makes landfall, the system weakens and eventually dissipates.
In the mid-levels (mid-troposphere), the MCC exhibits a cyclonic (counterclockwise in the Northern Hemisphere) rotating low pressure which is warm compared to the surrounding environment (referred to as a warm core). This mid-level circulation is referred to as a Mesoscale Convective Vortex. The upper-levels contain an anti-cyclonic (clockwise in the Northern Hemisphere) rotating high pressure which is a sign of divergence of air. This high pressure is colder relative to its surrounding environment.
This transition normally requires significant instability through the atmosphere, with temperature differences between the underlying ocean and the mid-levels of the troposphere requiring over 20 °C, or 72 °F, of contrast in this roughly layer of the lower atmosphere. The mode of the sea surface temperatures that subtropical cyclones form over is . Transition from subtropical cyclones into tropical cyclones occurs only in very rare cases over the South Atlantic Ocean, such as Hurricane Catarina in 2004.
Plot of Earth's atmospheric opacity to various wavelengths of electromagnetic radiation. This is the surface-to-space opacity, the atmosphere is transparent to longwave radio transmissions within the troposphere, not opaque as shown on the chart. Microwaves are radio waves of short wavelength, from about 10 centimeters to one millimeter, in the SHF and EHF frequency bands. Microwave energy is produced with klystron and magnetron tubes, and with solid state devices such as Gunn and IMPATT diodes.
Another form of atmospheric diffraction or bending of light occurs when light moves through fine layers of particulate dust trapped primarily in the middle layers of the troposphere. This effect differs from water based atmospheric diffraction because the dust material is opaque whereas water allows light to pass through it. This has the effect of tinting the light the color of the dust particles. This tinting can vary from red to yellow depending on geographical location.
The stratospheric temperature profile creates very stable atmospheric conditions, so the stratosphere lacks the weather-producing air turbulence that is so prevalent in the troposphere. Consequently, the stratosphere is almost completely free of clouds and other forms of weather. However, polar stratospheric or nacreous clouds are occasionally seen in the lower part of this layer of the atmosphere where the air is coldest. The stratosphere is the highest layer that can be accessed by jet-powered aircraft.
The retreat and thinning is attributed to a decrease in precipitation and a warming of the upper troposphere over the last several decades. Alerce Glacier, on the Argentinian side, can be visited from Refugio Otto Meiling, a mountain hut that is sandwiched between it and Castaño Overa Glacier. Castaño Overa, also on the Argentinian side, is smaller and relatively accessible by hike from Pampa Linda. Guided trekking tours allow visitors to cross Castaño Overa or walk to Tronador's peak.
The intermediate time scale results from fallout that has been put into the troposphere and ejected by precipitation during the first month. Long-term fallout can sometimes occur from deposition of tiny particles carried in the stratosphere. By the time that stratospheric fallout has begun to reach the earth, the radioactivity is very much decreased. Also, after a year it is estimated that a sizable quantity of fission products move from the northern to the southern stratosphere.
In addressing the topic, A. J. Dessler commented that any increased energy received in Earth's troposphere due to increased solar activity is negligible, and that correlations alone do not establish causation. The challenges facing scientists with complex systems like the planet's weather require finding a coupling mechanism. He suggested to continue seeking physical mechanisms. In 2004, Dessler refuted the proposition put forth by retired NASA scientist Addison Bain concerning the causes and combustion of the Hindenburg disaster.
Bioaerosols are typically introduced into the air via wind turbulence over a surface. Once airborne they typically remain in the planetary boundary layer (PBL), but in some cases reach the upper troposphere and stratosphere. Once in the atmosphere, they can be transported locally or globally: common wind patterns/strengths are responsible for local dispersal, while tropical storms and dust plumes can move bioaerosols between continents. Over ocean surfaces, bioaerosols are generated via sea spray and bubbles.
Norman Phillips in 2004 Norman A. Phillips (July 9, 1923 – March 15, 2019) was an American meteorologist notable for his contributions to geophysical fluid dynamics. In 1956, he developed a mathematical model that could realistically depict monthly and seasonal patterns in the troposphere, which became the first successful general circulation model of climate. Phillips was born in Chicago, Illinois. His parents, Alton Elmer Anton Phillips and Linnea (Larson) Phillips, were the children of Swedish immigrants to the United States.
A cloud étage is a meteorological term used to delimit any one of three main altitude levels in the troposphere where certain cloud types usually form. The term is derived from the French word which means floor or storey, as in the floor of a multi-storey building. With the exception of the low étage, the altitude range of each level varies according to latitude from Earth's equator to the arctic and antarctic regions at the poles.
Microwave Sounding Unit temperature measurements refers to temperature measurement using the Microwave Sounding Unit instrument and is one of several methods of measuring Earth atmospheric temperature from satellites. Microwave measurements have been obtained from the troposphere since 1979, when they were included within NOAA weather satellites, starting with TIROS-N. By comparison, the usable balloon (radiosonde) record begins in 1958 but has less geographic coverage and is less uniform. Microwave brightness measurements do not directly measure temperature.
These observations are irregularly spaced, so they are processed by data assimilation and objective analysis methods, which perform quality control and obtain values at locations usable by the model's mathematical algorithms. The data are then used in the model as the starting point for a forecast. A variety of methods are used to gather observational data for use in numerical models. Sites launch radiosondes in weather balloons which rise through the troposphere and well into the stratosphere.
Hegerl et al., Chapter 9: Understanding and Attributing Climate Change, Frequently Asked Question 9.2: Can the Warming of the 20th century be Explained by Natural Variability? Depletion of the ozone layer by chemical refrigerants stimulated a stratospheric cooling effect. If the Sun was responsible for observed warming, warming of the troposphere at the surface and warming at the top of the stratosphere would be expected as the increased solar activity would replenish ozone and oxides of nitrogen.
Most atmospheric deep convection occurs in the tropics as the rising branch of the Hadley circulation; and represents a strong local coupling between the surface and the upper troposphere which is largely absent in winter midlatitudes. Its counterpart in the ocean (deep convection downward in the water column) only occurs at a few locations. While less dynamically important than in the atmosphere, such oceanic convection is responsible for the worldwide existence of cold water in the lowest layers of the ocean.
There are many types of ice halos. They are produced by the ice crystals in cirrus or cirrostratus clouds high in the upper troposphere, at an altitude of to , or, during very cold weather, by ice crystals called diamond dust drifting in the air at low levels. The particular shape and orientation of the crystals are responsible for the types of halo observed. Light is reflected and refracted by the ice crystals and may split into colors because of dispersion.
Because of energy limitations, oxygen and nitrogen do not react at ambient temperatures. But at high temperatures, they undergo an endothermic reaction producing various oxides of nitrogen. Such temperatures arise inside an internal combustion engine or a power station boiler, during the combustion of a mixture of air and fuel, and naturally in a lightning flash. In atmospheric chemistry, the term denotes the total concentration of NO and since the conversion between these two species is rapid in the stratosphere and troposphere.
The geostrophic wind neglects frictional effects, which is usually a good approximation for the synoptic scale instantaneous flow in the midlatitude mid-troposphere. Although ageostrophic terms are relatively small, they are essential for the time evolution of the flow and in particular are necessary for the growth and decay of storms. Quasigeostrophic and semigeostrophic theory are used to model flows in the atmosphere more widely. These theories allow for divergence to take place and for weather systems to then develop..
Through natural processes in the atmosphere, it is oxidized to carbon dioxide and ozone. Carbon monoxide is short-lived in the atmosphere (with an average lifetime of about one to two months), and spatially variable in concentration. In the atmosphere of Venus carbon monoxide occurs as a result of the photodissociation of carbon dioxide by electromagnetic radiation of wavelengths shorter than 169 nm. Due to its long lifetime in the mid- troposphere, carbon monoxide is also used as tracer for pollutant plumes.
The brightening of the sunlit hemisphere is thought to result from the local thickening of the methane clouds and haze layers located in the troposphere. The bright collar at −45° latitude is also connected with methane clouds. Other changes in the southern polar region can be explained by changes in the lower cloud layers. The variation of the microwave emission from Uranus is probably caused by changes in the deep tropospheric circulation, because thick polar clouds and haze may inhibit convection.
Hansen et al. 2015 found, that the shutdown or substantial slowdown of the AMOC, besides possibly contributing to extreme end-Eemian events, will cause a more general increase of severe weather. Additional surface cooling from ice melt increases surface and lower tropospheric temperature gradients, and causes in model simulations a large increase of mid-latitude eddy energy throughout the midlatitude troposphere. This in turn leads to an increase of baroclinicity produced by stronger temperature gradients, which provides energy for more severe weather events.
Because Neptune's atmospheric methane content is similar to that of Uranus, some unknown atmospheric constituent is thought to contribute to Neptune's colour. Neptune's atmosphere is subdivided into two main regions: the lower troposphere, where temperature decreases with altitude, and the stratosphere, where temperature increases with altitude. The boundary between the two, the tropopause, lies at a pressure of . The stratosphere then gives way to the thermosphere at a pressure lower than 10−5 to 10−4 bars (1 to 10 Pa).
Diamonds are now also being recovered from the ocean floor off the Cape of Good Hope. Diamonds are found naturally, but about 30% of all industrial diamonds used in the U.S. are now manufactured. Carbon-14 is formed in upper layers of the troposphere and the stratosphere at altitudes of 9–15 km by a reaction that is precipitated by cosmic rays. Thermal neutrons are produced that collide with the nuclei of nitrogen-14, forming carbon-14 and a proton.
The African easterly jet is a region of the lower troposphere over West Africa where the seasonal mean wind speed is at a maximum and the wind is easterly. The temperature contrast between the Sahara Desert and the Gulf of Guinea causes the jet to form to the north of the monsoon trough. The jet's maximum wind speeds are at a height of . The jet moves northward from its south-most location in January, reaching its most northerly latitude in August.
Retrograde motion, or retrogression, within the Earth's atmosphere is seen in weather systems whose motion is opposite the general regional direction of airflow, i.e. from east to west against the westerlies or from west to east through the trade wind easterlies. Prograde motion with respect to planetary rotation is seen in the atmospheric super-rotation of the thermosphere of Earth and in the upper troposphere of Venus. Simulations indicate that the atmosphere of Pluto should be dominated by winds retrograde to its rotation.
The timing of the transition also influences changes in sea ice, ozone, air temperature, and cloudiness. Early and late polar breakup episodes have occurred, due to variations in the stratospheric flow structure and upward spreading of planetary waves from the troposphere. As a result of increased waves into the vortex, the vortex experiences more rapid warming than normal, resulting in an earlier breakup and spring. When the breakup comes early, it is characterized by with persistent of remnants of the vortex.
Most cloud cover and precipitation in association with cold lows occurs during the daylight hours as sunlight warms the Earth's surface, destabilizing the atmosphere and causing upward vertical motion. The development of severe weather, particularly tornadoes, can occur near the center of these systems over land during any season of the year. During winter, when cold-core lows with temperatures in the mid-levels of the troposphere reach move over open waters, deep convection forms which allows polar low development to become possible.
Tropospheric clouds exert numerous influences on Earth's troposphere and climate. First and foremost, they are the source of precipitation, thereby greatly influencing the distribution and amount of precipitation. Because of their differential buoyancy relative to surrounding cloud-free air, clouds can be associated with vertical motions of the air that may be convective, frontal, or cyclonic. The motion is upward if the clouds are less dense because condensation of water vapor releases heat, warming the air and thereby decreasing its density.
A sandstorm (Haboob) approaching Al Asad, Iraq, just before nightfall on April 27, 2005. Low-level outflow boundaries from thunderstorms are cooler and more moist than the air mass the thunderstorm originally formed within due to its wet bulbing by rain, forming a wedge of denser air which spreads out from the base of the parent thunderstorm. If wind speeds are high enough, such as during microburst events, dust and sand can be carried into the troposphere, reducing visibility.Western Region Climate Center (2002).
In the 1970s it was recognized by Richard Lindzen and James Holton that the periodic wind reversal was driven by atmospheric waves emanating from the tropical troposphere that travel upwards and are dissipated in the stratosphere by radiative cooling. The precise nature of the waves responsible for this effect was heavily debated; in recent years, however, gravity waves have come to be seen as a major contributor and the QBO is now simulated in a growing number of climate models.
Some small molecules in the atmosphere can also act as photoinitiators by decomposing to give free radicals (in photochemical smog). For instance, nitrogen dioxide is produced in large quantities by gasoline-burning internal combustion engines. NO2 in the troposphere gives smog its brown coloration and catalyzes production of toxic ground-level ozone. Molecular oxygen (O2) also serves as a photoinitiator in the stratosphere, breaking down into atomic oxygen and combining with O2 in order to form the ozone in the ozone layer.
Furthermore, it would take additional turbulence or convection at the upper limits of the PBL to inject bioaerosols into the troposphere where they may transported larger distances as part of tropospheric flow. This limits the concentration of bioaerosols at these altitudes. Cloud droplets, ice crystals, and precipitation use bioaerosols as a nucleus where water or crystals can form or hold onto their surface. These interactions show that air particles can change the hydrological cycle, weather conditions, and weathering around the world.
Clear-air turbulence (CAT) is the turbulent movement of air masses in the absence of any visual clues, such as clouds, and is caused when bodies of air moving at widely different speeds meet.Stull, B. R., 1988 An introduction to Boundary Layer Meteorology, Kluwert Academic Publishers 666 pp. The atmospheric region most susceptible to CAT is the high troposphere at altitudes of around as it meets the tropopause. Here CAT is most frequently encountered in the regions of jet streams.
Another important critique of the early satellite record was its shortness—adding a few years on to the record or picking a particular time frame could change the trends considerably. Through early 2005, even though they began with the same data, each of the major research groups had interpreted it with different results. Most notably, Mears et al. at RSS found 0.193 °C/decade for lower troposphere up to July 2005, compared to +0.123 °C/decade found by UAH for the same period.
The magnetosphere guides cosmic ray and solar energetic particles to polar latitudes, while high energy charged particles enter the mesosphere, stratosphere, and troposphere. These energetic particles at the top of the atmosphere shatter atmospheric atoms and molecules, creating harmful lower energy particles that penetrate deep into the atmosphere and create measurable radiation. All aircraft flying above 8 km (26,200 feet) altitude are exposed to these particles. The dose exposure is greater in polar regions than at mid-latitude and equatorial regions.
Thunderstorms form when air parcels are lifted vertically. Deep, moist convection requires a parcel to be lifted to the LFC where it then rises spontaneously until reaching a layer of non-positive buoyancy. The atmosphere is warm at the surface and lower levels of the troposphere where there is mixing (the planetary boundary layer (PBL)), but becomes substantially cooler with height. The temperature profile of the atmosphere, the change in temperature, the degree that it cools with height, is the lapse rate.
A larger version consisting of 32 elements strung between two towers was completed in January 1953, and underwent testing in February and March. Sea clutter was completely absorbed in the lower frequency receivers, and aircraft were easily detected in the higher frequencies, corresponding to faster movement. Signal strength turned out to be even better than expected because scattering off the troposphere added to the signal. The tests were very encouraging and led to plans for a production version that might be part of the ROTOR network.
The results obtained by Montzka et al. (2011) shows that the interannual variability in •OH estimated from CH3CCl3 measurements is small, indicating that global •OH is generally well buffered against perturbations. This small variability is consistent with measurements of methane and other trace gases primarily oxidized by •OH, as well as global photochemical model calculations. In 2014, researchers reported their discovery of a "hole" or absence of hydroxyl throughout the entire depth of the troposphere across a large region of the tropical West Pacific.
Because it is warmer, it is less dense and is prone to further ascent. In meteorology, instability can be described by various indices such as the Bulk Richardson Number, lifted index, K-index, convective available potential energy (CAPE), the Showalter, and the Vertical totals. These indices, as well as atmospheric instability itself, involve temperature changes through the troposphere with height, or lapse rate. Effects of atmospheric instability in moist atmospheres include thunderstorm development, which over warm oceans can lead to tropical cyclogenesis, and turbulence.
Finlayson-Pitts' research focuses on developing a molecular- level understanding of the fundamental kinetics, mechanisms, and photochemistry of gaseous reactions of particles. She is particularly interested in how reactions occur in different layers of the atmosphere, and at the interfaces of different layers. In addition to her work on the troposphere and stratosphere, she studies interactions at the interface between air and water, where gases meet liquids. Reactions that occur at the surface between layers may differ from the reactions that occur within each layer.
Criegee zwitterion A Criegee intermediate (also called a Criegee zwitterion or Criegee biradical) is a molecule containing the oxide of a carbonyl group. These chemicals may react with sulfur dioxide and nitrogen oxides in the earth's atmosphere, and are implicated in the formation of aerosols, which are an important factor in controlling global climate. Criegee intermediates are also an important source of OH (hydroxyl radicals). OH radicals are the most important oxidant in the troposphere, and are important in controlling air quality and pollution.
Nitrous oxide is a greenhouse gas with a global warming potential 298 times that of carbon dioxide. Global warming potential is a way to compare global warming impacts of different gases relative to carbon dioxide emissions. Since nitrous oxide has such a high global warming potential, it is able to warm the earth more effectively compared to other greenhouse gases. Although generally unreactive in the troposphere, nitrous oxide is destroyed during photolysis or reactions with excited oxygen atoms and catalyzes the destruction of ozone in the stratosphere.
Typical cirrus clouds may be susceptible to modification to reduce their lifetime and optical thickness, and hence their net positive radiative forcing (in contrast to the typical low, warm liquid clouds). Material to seed such modification could be delivered via drones or by aircraft. Scientists believe that cirrus clouds in the high latitude upper troposphere are formed by homogeneous freezing, resulting in large numbers of small ice crystals. If effective ice nuclei were introduced into this environment, the cirrus may instead form by heterogeneous freezing.
Cloud physics is the study of the physical processes that lead to the formation, growth and precipitation of atmospheric clouds. These aerosols are found in the troposphere, stratosphere, and mesosphere, which collectively make up the greatest part of the homosphere. Clouds consist of microscopic droplets of liquid water (warm clouds), tiny crystals of ice (cold clouds), or both (mixed phase clouds). Cloud droplets initially form by the condensation of water vapor onto condensation nuclei when the supersaturation of air exceeds a critical value according to Köhler theory.
It is not enough for molecules of water to form an ice lattice at saturation pressures; they require a surface to condense on to or conglomerations of liquid water molecules of water to freeze. For these reasons, relative humidities over ice in the atmosphere can be found above 100%, meaning supersaturation has occurred. Supersaturation of water is actually very common in the upper troposphere, occurring between 20% and 40% of the time. This can be determined using satellite data from the Atmospheric Infrared Sounder.
Heating of the earth near the equator leads to large amounts of convection along the monsoon trough or Intertropical convergence zone. This air mass rises to the lower stratosphere where it diverges, moving away from the equator in the upper troposphere in both northerly and southerly directions. As it moves towards the mid-latitudes on both sides of the equator, the air cools and sinks. The resulting air mass subsidence creates a subtropical ridge of high pressure near the 30th parallel in both hemispheres.
Diagram showing the five primary layers of the Earth's atmosphere: exosphere, thermosphere, mesosphere, stratosphere, and troposphere. The layers are to scale. From the Earth's surface to the top of the stratosphere (50km) is just under 1% of Earth's radius. The exosphere ( "outside, external, beyond", "sphere") is a thin, atmosphere-like volume surrounding a planet or natural satellite where molecules are gravitationally bound to that body, but where the density is too low for them to behave as a gas by colliding with each other.
Antarctic systems tend to be weaker than their northern counterparts since the air-sea temperature differences around the continent are generally smaller . However, vigorous polar lows can be found over the Southern Ocean. During winter, when cold-core lows with temperatures in the mid-levels of the troposphere reach move over open waters, deep convection forms, which allows polar low development to become possible. The systems usually have a horizontal length scale of less than and exist for no more than a couple of days.
The great majority of photogeochemical research is performed in the laboratory, as it is easier to demonstrate and observe a particular reaction under controlled conditions. This includes confirming the identity of materials, designing reaction vessels, controlling light sources, and adjusting the reaction atmosphere. However, observation of natural phenomena often provides initial inspiration for further study. For example, during the 1970s it was generally agreed that nitrous oxide (N2O) has a short residence time in the troposphere, although the actual explanation for its removal was unknown.
The wavelength of SHF waves creates strong reflections from metal objects the size of automobiles, aircraft, and ships, and other vehicles. This and the narrow beamwidths possible with high gain antennas and the low atmospheric attenuation as compared with higher frequencies make SHF the main frequencies used in radar. Attenuation and scattering by moisture in the atmosphere increase with frequency, limiting the use of high SHF frequencies for long range applications. Small amounts of microwave energy are randomly scattered by water vapor molecules in the troposphere.
Dropsonde transmissions are collected and checked by an on-board Flight Director, who then transmits the data to the National Centers for Environmental Prediction (NCEP) and the National Hurricane Center (NHC) for analysis. The G-IV serves the NCEP Winter Storm Reconnaissance program in order to better predict the location and intensity of winter storms that affect the United States. During winter storm reconnaissance, air chemistry measurements are also taken from the upper troposphere. These flights are typically flown from Honolulu, Anchorage, or Yokota AB, Japan.
The atmosphere's temperature decreases with height in the troposphere. Since emission of infrared radiation varies with temperature, longwave radiation escaping to space from the relatively cold upper atmosphere is less than that emitted toward the ground from the lower atmosphere. Thus, the strength of the greenhouse effect depends on the atmosphere's rate of temperature decrease with height. Both theory and climate models indicate that global warming will reduce the rate of temperature decrease with height, producing a negative lapse rate feedback that weakens the greenhouse effect.
Volcanic eruptions of a large magnitude can impact global climate, reducing the amount of solar radiation reaching the Earth's surface, lowering temperatures in the troposphere, and changing atmospheric circulation patterns. Large-scale volcanic activity may last only a few days, but the massive outpouring of gases and ash can influence climate patterns for years. Sulfuric gases convert to sulfate aerosols, sub-micron droplets containing about 75 percent sulfuric acid. Following eruptions, these aerosol particles can linger as long as three to four years in the stratosphere.
Thunderstorms may line up in a series or become a rainband, known as a squall line. Strong or severe thunderstorms include some of the most dangerous weather phenomena, including large hail, strong winds, and tornadoes. Some of the most persistent severe thunderstorms, known as supercells, rotate as do cyclones. While most thunderstorms move with the mean wind flow through the layer of the troposphere that they occupy, vertical wind shear sometimes causes a deviation in their course at a right angle to the wind shear direction.
Meteor-3M No.1 includes the SAGE III (Stratospheric Aerosol and Gas Experiment) payload and other instruments designed to measure temperature and humidity profiles, clouds, surface properties, and high energy particles in the upper atmosphere. SAGE III is a gyrating spectrometer that measures ultraviolet/visible energy that will be used to enhance our understanding of natural and human-derived atmospheric processes by providing accurate long-term measurements of the vertical structure of aerosols, ozone, water vapor, and other important trace gases in the upper troposphere and stratosphere.
The optical depth of the two upper cloud layers varies with latitude: both become thinner at the poles as compared to the equator, though in 2007 the methane cloud layer's optical depth had a local maximum at 45°S, where the southern polar collar is located (see below). The troposphere is very dynamic, exhibiting strong zonal winds, bright methane clouds, dark spots and noticeable seasonal changes. (see below) Temperature profiles in the stratosphere and thermosphere of Uranus. The shaded area is where hydrocarbons are concentrated.
However, a more well-defined circulation quickly took hold with an associated curved rainband appearing on the system, leading MFR to designate the system as Tropical Disturbance 07 between Mauritius and Rodrigues on 23 January. Due to westerly flow in the mid-troposphere, the newly classified disturbance took an east-southeasterly course. Though the storm's convection was variable, wind shear limited convection to the northern quadrants of the circulation. The disturbance was upgraded to a Tropical Depression based on scatterometer data later that day.
During the early 1980s Lioy recognized that the public health metric for defining exposure of the general population to troposphere ozone (smog) was incorrect and that the one-hour standard for peak ozone levels should be replaced by an eight-hour standard. Independently, Peter Rombout, RIVM, Netherlands, discovered the same issue. In 1986, they collaborated and published an article on the need for an eight-hour ozone standard. Lioy's group also conducted research on the relationship between ozone exposure and visits to emergency rooms during the summertime.
Nonconvective stratiform clouds appear in stable airmass conditions and, in general, have flat, sheet-like structures that can form at any altitude in the troposphere. The stratiform group is divided by altitude range into the genera cirrostratus (high-level), altostratus (mid-level), stratus (low-level), and nimbostratus (multi-level). Fog is commonly considered a surface-based cloud layer. The fog may form at surface level in clear air or it may be the result of a very low stratus cloud subsiding to ground or sea level.
Clouds of this structure have both cumuliform and stratiform characteristics in the form of rolls, ripples, or elements. They generally form as a result of limited convection in an otherwise mostly stable airmass topped by an inversion layer. If the inversion layer is absent or higher in the troposphere, increased airmass instability may cause the cloud layers to develop tops in the form of turrets consisting of embedded cumuliform buildups. The stratocumuliform group is divided into cirrocumulus (high-level), altocumulus (mid-level), and stratocumulus (low-level).
Space Shuttle Endeavour appears to straddle the stratosphere and mesosphere in this photo. "The orange layer is the troposphere, where all of the weather and clouds are generated and contained. This orange layer gives way to the whitish Stratosphere and then into the Mesosphere." (The shuttle is actually orbiting at more than in altitude, far above this transition layer.) This image shows the temperature trend in the lower stratosphere as measured by a series of satellite-based instruments between January 1979 and December 2005.
Fu's research has spanned topics including convection, cloud and precipitation processes and their role in climate; atmospheric transport in the upper troposphere and lower stratosphere; interactions between the atmosphere, the ocean, and the vegetation produced by the land; and satellite remote sensing applications and retrievals. Fu's research in the Amazon and across South America has demonstrated the importance of maintenance of the rainforest in sustaining the rainfall rates of the Amazon. Fu hopes to expands these research efforts to other areas such as the Congo.
Nitrous oxide is one of the most prominent anthropogenic ozone-depleting gases in the atmosphere. It is released into the atmosphere primarily through natural sources such as soil and rock, as well as anthropogenic process like farming. Atmospheric nitrous oxide is also created in the atmosphere as a product of a reaction between nitrogen and electronically excited ozone in the lower thermosphere. The Atmospheric Chemistry Experiment‐Fourier Transform Spectrometer (ACE-FTS) is a tool used for measuring nitrous oxide concentrations in the upper to lower troposphere.
Since 2013, Mims has used several LED twilight photometers to detect layers of smoke and dust in the troposphere and volcanic aerosols in the stratosphere. Sulfur dioxide from the 21-23 June 2019 volcanic eruption of Raikoke reached the stratosphere and covered much of the northern hemisphere with a veil of sulfuric acid aerosols. Mims’ twilight photometry from Central Texas and lidar measurements from Hawaii indicated that the elevation of the densest portion of the veil reached 25 km and was typically 16-20 km.
The planetary boundary layer (PBL) is the part of the troposphere that is directly influenced by the presence of the earth’s surface, and responds to surface forcings with a timescale of about an hour or less . Convective turbulent mixing processes are dominant in the mixed layer (ML) of the PBL and have a major influence on the growth and transport of atmospheric pollutants. Meteorological variables (i.e. temperature, humidity, wind) in the PBL are critically important as inputs for reliable simulations in air quality models.
A significantly delayed, ultimately denied engineering request and several extensions pushed completion of the station well into the 1990s. In January 1997, Troposphere Broadcasting L.P. reached an agreement to sell the permit to build KSEA to Farmworker Educational Radio Network, Inc. The deal gained FCC approval on March 13, 1997, and formal consummation of the transaction took place on June 11, 1997. After more engineering changes, construction and testing were completed in September 1998, and the station was granted its broadcast license on December 4, 1998.
The stratosphere is very dry; unlike the troposphere, it rarely allows clouds to form. In the extreme cold of the polar winter, however, stratospheric clouds of different types may form, which are classified according to their physical state and chemical composition. Due to their high altitude and the curvature of the surface of the Earth, these clouds will receive sunlight from below the horizon and reflect it to the ground, shining brightly well before dawn or after dusk. PSCs form at very low temperatures, below .
It has basically all the weather-associated cloud genus types generated by active wind circulation, although very tall cumulonimbus thunder clouds can penetrate the tropopause from below and rise into the lower part of the stratosphere. Most conventional aviation activity takes place in the troposphere, and it is the only layer that can be accessed by propeller-driven aircraft. orbiting in the thermosphere. Because of the angle of the photo, it appears to straddle the stratosphere and mesosphere that actually lie more than below.
Models use systems of differential equations based on the laws of physics, fluid motion, and chemistry, and use a coordinate system which divides the planet into a 3D grid. Winds, heat transfer, radiation, relative humidity, and surface hydrology are calculated within each grid and evaluate interactions with neighboring points. A global forecast model is a weather forecasting model which initializes and forecasts the weather throughout the Earth's troposphere. It is a computer program that produces meteorological information for future times at given locations and altitudes.
In atmospheric science, a cold-trap is a layer of the atmosphere that is substantially colder than both the deeper and higher layers. For example, for Earth's troposphere, the temperature of the air drops with increasing height reaching a low point (at about 20 kilometers height). This region is called a cold-trap, because it traps ascending gases with high melting points, forcing them to drop back into Earth. For humans, the most important gas to be kept in that way is water vapor.
Sebastian Oberthür, International Environmental Agreements July 2001, Volume 1, Issue 3, pp 357-377, Linkages between the Montreal and Kyoto Protocols – Enhancing Synergies between Protecting the Ozone Layer and the Global Climate While the general public tends to see global warming as a subset of ozone depletion, in fact ozone and chemicals such as chlorofluorocarbons (CFCs) and other halocarbons, which are held responsible for ozone depletion, are important greenhouse gasses. Furthermore, natural levels of ozone in both the stratosphere and troposphere have a warming effect.
Gaseous hydroperoxyl is involved in reaction cycles that destroy stratospheric ozone. It is also present in the troposphere, where it is essentially a byproduct of the oxidation of carbon monoxide and of hydrocarbons by the hydroxyl radical. Because dielectric constant has a strong effect on pKa, and the dielectric constant of air is quite low, superoxide produced (photochemically) in the atmosphere is almost exclusively present as HO2. As HO2 is quite reactive, it acts as a "cleanser" of the atmosphere by degrading certain organic pollutants.
When they feel threatened, they can assemble into huge clouds, able to travel at a high speed and even to climb to the top of the troposphere. These swarms display complex behavior arising from self-organization and can incapacitate any intelligent threat by a powerful surge of electromagnetic interference. Condor's crew suffered a complete memory erasure as a consequence of attacks from these "clouds". Invincible's crew mounts an escalating series of attacks on the perceived enemy, but eventually recognizes the futility of their efforts.
This "dome" feature appears above the strongest updraft location on the anvil of the storm. It is a result of an updraft powerful enough to break through the upper levels of the troposphere into the lower stratosphere. An observer at ground level and close to the storm may be unable to see the overshooting top because the anvil blocks the sight of this feature. The overshooting is visible from satellite images as a "bubbling" amidst the otherwise smooth upper surface of the anvil cloud.
Project HARP, a prototype of a space gun. A space gun is a proposed method of launching an object into outer space using a large gun, or cannon. Science fiction writer Jules Verne proposed such a launch method in From the Earth to the Moon, and in 1902 a movie, A Trip to the Moon, was adapted. However, even with a "gun barrel" through both the Earth's crust and troposphere, the g-forces required to generate escape velocity would still be more than what a human tolerates.
In 1883, the catastrophic eruption of Krakatoa, a volcanic island in Lampung, which registered as a 6 on the Volcanic Explosivity Index (VEI), and the tsunamis that ensued killed about 36,000 people, and approximately two-thirds of the original island was destroyed as well. The 2010 the eruption of Mount Merapi, a stratovolcano, began in late October and continued into November. This eruption had a VEI of 4, and it also released a sulfur dioxide cloud between 12,000 and 15,000 km into the upper troposphere.
Aurora australis observed from , May 1991 Space weather is a branch of space physics and aeronomy, or heliophysics, concerned with the time varying conditions within the Solar System, including the solar wind, emphasizing the space surrounding the Earth, including conditions in the magnetosphere, ionosphere, thermosphere, and exosphere. Space weather is distinct from but conceptually related to the terrestrial weather of the atmosphere of Earth (troposphere and stratosphere). The term space weather was first used in the 1950s and came into common usage in the 1990s.
In 1954, Carl-Gustav Rossby's group at the Swedish Meteorological and Hydrological Institute used the same model to produce the first operational forecast (i.e., a routine prediction for practical use). Operational numerical weather prediction in the United States began in 1955 under the Joint Numerical Weather Prediction Unit (JNWPU), a joint project by the U.S. Air Force, Navy and Weather Bureau. In 1956, Norman Phillips developed a mathematical model which could realistically depict monthly and seasonal patterns in the troposphere; this became the first successful climate model.
An aerosol is a suspension of fine solid particles or liquid droplets in a gas. The sulfate particles or sulfuric acid droplets in the atmosphere are about 0.1 to 1.0 micrometer (a millionth of a meter) in diameter. Sulfur aerosols are common in the troposphere as a result of pollution with sulfur dioxide from burning coal, and from natural processes. Volcanos are a major source of particles in the stratosphere as the force of the volcanic eruption propels sulfur-containing gases into the stratosphere.
Water vapor has a continuum absorption due to collisional broadening of absorption lines which extends through the window. Local very high humidity can completely block the infrared vibrational window. Over the Atlas Mountains, interferometrically recorded spectra of outgoing longwave radiation show emission that has arisen from the land surface at a temperature of about 320 K and passed through the atmospheric window, and non- window emission that has arisen mainly from the troposphere at temperatures about 260 K. Over Côte d'Ivoire, interferometrically recorded spectra of outgoing longwave radiation show emission that has arisen from the cloud tops at a temperature of about 265 K and passed through the atmospheric window, and non-window emission that has arisen mainly from the troposphere at temperatures about 240 K. This means that, at the scarcely absorbed continuum of wavelengths (8 to 14 μm), the radiation emitted, by the earth's surface into a dry atmosphere, and by the cloud tops, mostly passes unabsorbed through the atmosphere, and is emitted directly to space; there is also partial window transmission in far infrared spectral lines between about 16 and 28 μm. Clouds are excellent emitters of infrared radiation.
The carrier aircraft (initially a NASA B-52, now an L-1011 owned by Orbital) serves as a booster to increase payloads at reduced cost. is only about 4% of a low earth orbital altitude, and the subsonic aircraft reaches only about 3% of orbital velocity, yet by delivering the launch vehicle to this speed and altitude, the reusable aircraft replaces a costly first-stage booster. The single biggest cause of traditional launch delays is weather. Carriage to 40,000 feet takes the Pegasus above the troposphere, into the stratosphere.
Using charts of mean 200-hectopascal circulation for July through August (located above sea level) to locate the circumpolar troughs and ridges, trough lines extend over the eastern and central North Pacific and over the North Atlantic. Case studies of upper tropospheric cyclones in the Atlantic and Pacific have been performed by using airplane reports (winds, temperatures and heights), radiosonde data, geostationary satellite cloud imagery, and cloud-tracked winds throughout the troposphere. It was determined they were the origin of an upper tropospheric cold-core lows, or cut-off lows.
The tropical upper tropospheric cyclone has a cold core, meaning it is stronger aloft than at the Earth's surface, or stronger in areas of the troposphere with lower pressures. This is explained by the thermal wind relationship. It also means that a pool of cold air aloft is associated with the feature. If both an upper tropospheric cold-core low and lower tropospheric easterly wave trough are in-phase, with the easterly wave near or to the east of the upper level cyclone, thunderstorm development (also known as moist convection) is enhanced.
Three notable medicanes developed in 1996. The first, in mid-September 1996, was a typical Mediterranean tropical cyclone that developed in the Balearic Islands region. At the time of the cyclone's formation, a powerful Atlantic cold front and a warm front associated with a large-scale low, producing northeasterly winds over the Iberian peninsula, extended eastward into the Mediterranean, while abundant moisture gathered in the lower troposphere over the Balearic channel. On the morning of 12 September, a disturbance developed off of Valencia, Spain, dropping heavy rainfall on the coast even without coming ashore.
Considering his interests in cosmic rays and mountaineering, it was a natural development for Narkiewicz-Jodko to take to the skies as a balloonist. A high point in this area of his career came on March 29, 1936, when with a scientific colleague he succeeded in taking the balloon Warszawa II (Warsaw II) up to a height of 10,000 metres for the purpose of scientific measurements.S. Ziemecki & K. Narkiewicz-Jodko, 'Continuous Variation of Cosmic Ray Intensity in the Higher Layers of the Troposphere', in Acad. Polonaise Sciences et Lettres, bulletin no.
In addition, the strong contrast between the cold air of the high troposphere layers and the warm and moist air ejected by aircraft engines causes rapid sublimation of water vapor forming small ice crystals. This process is also enhanced by the presence of abundant nuclei of condensation produced as a result of combustion. These clouds are commonly known as condensation trails (contrails) and are initially lineal cirrus clouds that could be called Cirrus homogenitus (Cia). Due to the large temperature difference between the air exhausted and the ambiance air generates small-scale convection processes.
These processes favor the evolution of the condensation trails to Cirrocumulus homogenitus (Cca). Depending on the atmospheric conditions at the upper part of the troposphere, where the plane is flying, these high clouds rapidly disappear or persist. When the air is dry and stable, the water rapidly evaporates inside the contrails and can only observed up to several hundreds of meters from the plane. On the other hand, if humidity is high enough it exists an ice oversaturation and the homogenitus get wide and it can exist for hours.
The idealized greenhouse model is a simplification. In reality the atmosphere near the Earth's surface is largely opaque to thermal radiation and most heat loss from the surface is by convection. However radiative energy losses become increasingly important higher in the atmosphere, largely because of the decreasing concentration of water vapor, an important greenhouse gas. Rather than the surface itself, it is more realistic to think of the greenhouse effect as applying to a layer in the mid-troposphere, which is effectively coupled to the surface by a lapse rate.
Atmospheric Chemistry and Physics is an open access peer-reviewed scientific journal published by the European Geosciences Union. It covers research on the Earth's atmosphere and the underlying chemical and physical processes, including the altitude range from the land and ocean surface up to the turbopause, including the troposphere, stratosphere, and mesosphere. The main subject areas comprise atmospheric modelling, field measurements, remote sensing, and laboratory studies of gases, aerosols, clouds and precipitation, isotopes, radiation, dynamics, and biosphere and hydrosphere interactions. Article types published are research and review articles, technical notes, and commentaries.
Equivalent effective stratospheric chlorine (EESC) provides an estimate of the total effective amount of halogens (chlorine and bromine) in the stratosphere. It is calculated from emission of chlorofluorocarbon and related halogenated compounds into the troposphere (lower atmosphere) and their efficiency in contributing to stratospheric ozone depletion (ozone depletion potential, ODP), and by making assumptions on transport times into the upper atmosphere (stratosphere).Newman, P. A., Daniel, J. S., Waugh, D. W., and Nash, E. R.: A new formulation of equivalent effective stratospheric chlorine (EESC), Atmos. Chem. Phys., 7, 4537-4552, , 2007.
The Fennec observational programme included ground sites at Bordj Badji Mokhtar in Algeria, Zouerat in Mauritania as well as 8 automatic weather stations located in the remote desert in both Algeria and Mauritania. The Bordj Badji Mokhtar station is in the remote Sahara on the Mali-Algerian border. In June 2011 an array of instrumentation designed to monitor the troposphere was set up at Bordj Badi Mokhtar. The instrumentation included Lidar, sodar, 4-8 radiosondes daily, a flux tower and aerosol sampling equipment (AERONET cimel sun photometer, nephelometer and filters).
The near-surface wind field of a tropical cyclone is characterized by air rotating rapidly around a center of circulation while also flowing radially inwards. At the outer edge of the storm, air may be nearly calm; however, due to the Earth's rotation, the air has non-zero absolute angular momentum. As air flows radially inward, it begins to rotate cyclonically (counter-clockwise in the Northern Hemisphere, and clockwise in the Southern Hemisphere) to conserve angular momentum. At an inner radius, air begins to ascend to the top of the troposphere.
A characteristic value of the maximum potential intensity, v_p, is . However, this quantity varies significantly across space and time, particularly within the seasonal cycle, spanning a range of . This variability is primarily due to variability in the surface enthalpy disequilibrium ( \Delta k ) as well as in the thermodynamic structure of the troposphere, which are controlled by the large-scale dynamics of the tropical climate. These processes are modulated by factors including the sea surface temperature (and underlying ocean dynamics), background near-surface wind speed, and the vertical structure of atmospheric radiative heating.
The rising air creates a low pressure zone near the equator. As the air moves poleward, it cools, becomes denser, and descends at about the 30th parallel, creating a high-pressure area. The descended air then travels toward the equator along the surface, replacing the air that rose from the equatorial zone, closing the loop of the Hadley cell. The poleward movement of the air in the upper part of the troposphere deviates toward the east, caused by the coriolis acceleration (a manifestation of conservation of angular momentum).
Kerala state received unprecedented rains during the month of July 1924. Kerala received 3,368 mm of rain during the monsoon season (June to September), 64 per cent higher than normal and is the highest recorded rainfall. The flood was probably caused by offshore vortices along the west coast and perturbations higher up in the troposphere and is not attributed to any depression or cyclonic disturbance in the Arabian sea or the bay of Bengal. The rivers in the state were in spate and a sudden opening of the Mullaperiyar sluices caused even greater misery.
The third layer is the mesosphere which extends from 50 km to about 80 km. There are other layers above 80 km, but they are insignificant with respect to atmospheric dispersion modeling. The lowest part of the troposphere is called the atmospheric boundary layer (ABL) or the planetary boundary layer (PBL) . The air temperature of the atmosphere decreases with increasing altitude until it reaches what is called an inversion layer (where the temperature increases with increasing altitude) that caps the Convective Boundary Layer, typically to about 1.5 to 2.0 km in height.
Solar tides will refer to only thermal solar tides from this point. Solar energy is absorbed throughout the atmosphere some of the most significant in this context are water vapor at (≈0-15 km) in the troposphere, ozone at (≈30 to 60 km) in the stratosphere and molecular oxygen and molecular nitrogen at (≈120 to 170 km) in the thermosphere. Variations in the global distribution and density of these species result in changes in the amplitude of the solar tides. The tides are also affected by the environment through which they travel.
The ozone hole is a relatively stable structure caused by a combination of pollution and antarctic wind patterns in the stratosphere. Water vapor concentration (humidity) varies considerably, especially in the troposphere, and is a major component of weather. Water evaporation is driven by heat from incoming solar radiation, and temperature variations can cause water-saturated air to expunge water in the form of rain, snow, or fog. The heat gained and lost by water through these processes increases turbulence in the lower atmosphere, especially at mesoscale and microscale.
On September 11, 1996, a weak low-pressure area was situated close to Lake Superior, as well as a shortwave trough over Ontario. Its surface central pressure over Lake Michigan was . The northwest tilt of the low indicated that the surface center was strengthening due to baroclinic forcing. In addition to this, analyses of the atmosphere concluded that the cyclone extended into the upper troposphere. The cyclone's overall strength increased dramatically while meandering over the Great Lakes, with surface winds building from 11 mph (18 km/h) to 67 mph (108 km/h).
Aluminium-26 can be used to calculate the terrestrial age of meteorites and comets. It is produced in significant quantities in extraterrestrial objects via spallation of silicon alongside beryllium-10, though after falling to Earth, 26Al production ceases and its abundance relative to other cosmogenic nuclides decreases. Absence of aluminium-26 sources on Earth is a consequence of Earth's atmosphere obstructing silicon on the surface and low troposphere from interaction with cosmic rays. Consequently, the amount of 26Al in the sample can be used to calculate the date the meteorite fell to Earth.
They showed that the climate system may be responding faster than the models indicate. Rahmstorf and coauthors showed concern that sea levels are rising at the high range of the IPCC projections, and that this was due to thermal expansion and not from melting of the Greenland or Antarctic ice sheets. Following the launch of spacecraft capable of determining temperatures, Roy Spencer and John Christy published the first version of their satellite temperature measurements in 1990. Contrary to climate models and surface measurements, their results showed a cooling in the troposphere.
Haigh is known for her work on solar variability, and also works on radiative transfer, stratosphere- troposphere coupling and climate modelling. She has been Editor of the Journal of the Atmospheric Sciences and a Lead Author on the Third Assessment Report of the Intergovernmental Panel on Climate Change. She is a Fellow of the Institute of Physics. In 2004 she received the Institute of Physics' Charles Chree Medal and Prize and in 2010 the Royal Meteorological Society Adrian Gill prize for her work on solar variability and its effects on climate.
At level with stratus nebulosus translucidus (V-89) and opacus (V-90) clouds Stratus fractus (V-88) cloud Abbreviation: St Clouds of the genus stratus form in low horizontal layers having a ragged or uniform base. Ragged stratus often forms in precipitation while more uniform stratus forms in maritime or other moist stable air mass conditions. The latter often produces drizzle. Stratus that touches the Earth's surface is given the common name, fog, rather than a Latin name that applies only to clouds that form and remain aloft in the troposphere.
The most effective sink of atmospheric methane is the hydroxyl radical in the troposphere, or the lowest portion of Earth's atmosphere. As methane rises into the air, it reacts with the hydroxyl radical to create water vapor and carbon dioxide. The mean lifespan of methane in the atmosphere was estimated at 9.6 years as of 2001; however, increasing emissions of methane over time reduce the concentration of the hydroxyl radical in the atmosphere. With less OH˚ to react with, the lifespan of methane could also increase, resulting in greater concentrations of atmospheric methane.
Brominated substances have usually higher ODPs in range 5–15, because of more aggressive bromine reaction with ozone. Hydrochlorofluorocarbons have ODPs mostly in range 0.005 - 0.2 due to the presence of the hydrogen which causes them to react readily in the troposphere, therefore reducing their chance to reach the stratosphere where the ozone layer is present. Hydrofluorocarbons (HFC) have no chlorine content, so their ODP is essentially zero. ODP is often used in conjunction with a compound's global warming potential (GWP) as a measure of how environmentally detrimental it can be.
A cloud over the limb of Triton, taken by Voyager 2 Nitrogen ice particles form clouds in the troposphere a few kilometers above the surface of Triton. Above them a haze is present extending up to 30 km from the surface. It is believed to be composed largely of hydrocarbons and nitriles created by the action of the Sun's and stellar ultraviolet light on methane. In 1989 Voyager 2 discovered that near the surface there are winds blowing to the east or north-east with a speed of about 5–15 m/s.
Despite otherwise inhibiting environmental factors, the eye reappeared for a two-hour period before fully succumbing to the dry air and 55 km/h (35 mph) wind shear. Rapid weakening soon proceeded, and by mid-day on 7 December, the storm's coldest cloud tops were displaced east of the center of circulation; Ambali's motion also became erratic as winds in the lower levels of the troposphere began to govern its track. On 8 December, Ambali degenerated to a remnant low and MFR issued their last advisory on the dissipating system.
Certain criteria need to be met for their formation. In most situations, water temperatures of at least are needed down to a depth of at least ; waters of this temperature cause the overlying atmosphere to be unstable enough to sustain convection and thunderstorms. Another factor is rapid cooling with height, which allows the release of the heat of condensation that powers a tropical cyclone. High humidity is needed, especially in the lower-to-mid troposphere; when there is a great deal of moisture in the atmosphere, conditions are more favorable for disturbances to develop.
These maps show the average amount of water vapor in a column of atmosphere in a given month.(click for more detail) MODIS/Terra global mean atmospheric water vapor in atm-cm (centimeters of water in an atmospheric column if it condensed) Because water molecules absorb microwaves and other radio wave frequencies, water in the atmosphere attenuates radar signals. In addition, atmospheric water will reflect and refract signals to an extent that depends on whether it is vapor, liquid or solid. Generally, radar signals lose strength progressively the farther they travel through the troposphere.
Note that the meridional circulation is much lower than the zonal circulation, which transports heat between the day and night sides of the planet All winds on Venus are ultimately driven by convection. Hot air rises in the equatorial zone, where solar heating is concentrated and flows to the poles. Such an almost-planetwide overturning of the troposphere is called Hadley circulation. However, the meridional air motions are much slower than zonal winds. The poleward limit of the planet-wide Hadley cell on Venus is near ±60° latitudes.
Going upwards from the ground, these are the troposphere, stratosphere, mesosphere, thermosphere, and exosphere. The density of air is mainly determined by temperature and water vapor content, the density of sea water by temperature and salinity, and the density of lake water by temperature. Where stratification occurs, there may be thin layers in which temperature or some other property changes more rapidly with height or depth than the surrounding fluid. Depending on the main sources of buoyancy, this layer may be called a pycnocline (density), thermocline (temperature), halocline (salinity), or chemocline (chemistry, including oxygenation).
Research models that match well with observations suggest that clouds on Titan cluster at preferred coordinates and that cloud cover varies by distance from the surface on different parts of the satellite. In the polar regions (above 60 degrees latitude), widespread and permanent ethane clouds appear in and above the troposphere; at lower latitudes, mainly methane clouds are found between 15 and 18 km, and are more sporadic and localized. In the summer hemisphere, frequent, thick but sporadic methane clouds seem to cluster around 40°. Ground-based observations also reveal seasonal variations in cloud cover.
Scientists are connecting a delay in the Arctic vortex breakup with a reduction of planetary wave activities, few stratospheric sudden warming events, and depletion of ozone. Low pressure area over Quebec, Maine, and New Brunswick, part of the northern polar vortex weakening, on the record-setting cold morning of January 21, 1985 Sudden stratospheric warming events are associated with weaker polar vortices. This warming of stratospheric air can reverse the circulation in the Arctic Polar Vortex from counter-clockwise to clockwise. These changes aloft force changes in the troposphere below.
An example of an effect on the troposphere is the change in speed of the Atlantic Ocean circulation pattern. A soft spot just south of Greenland is where the initial step of downwelling occurs, nicknamed the "Achilles Heel of the North Atlantic". Small amounts of heating or cooling traveling from the polar vortex can trigger or delay downwelling, altering the Gulf Stream Current of the Atlantic, and the speed of other ocean currents. Since all other oceans depend on the Atlantic Ocean's movement of heat energy, climates across the planet can be dramatically affected.
All air entering the stratosphere must pass through the tropopause, the temperature minimum that divides the troposphere and stratosphere. The rising air is literally freeze dried; the stratosphere is a very dry place. The top of the stratosphere is called the stratopause, above which the temperature decreases with height. Sydney Chapman gave a correct description of the source of stratospheric ozone and its ability to generate heat within the stratosphere; he also wrote that ozone may be destroyed by reacting with atomic oxygen, making two molecules of molecular oxygen.
The genitus and mutatus categories have been expanded to include certain types that do not originate from pre-existing clouds. The term flammagenitus (Latin for 'fire-made') applies to cumulus congestus or cumulonimbus that are formed by large scale fires or volcanic eruptions. Smaller low-level "pyrocumulus" or "fumulus" clouds formed by contained industrial activity are now classified as cumulus homogenitus (Latin for 'man-made'). Contrails formed from the exhaust of aircraft flying in the upper level of the troposphere can persist and spread into formations resembling cirrus which are designated cirrus homogenitus.
High-level genus-types particularly show this duality with both short-wave albedo cooling and long-wave greenhouse warming effects. On the whole, ice-crystal clouds in the upper troposphere (cirrus) tend to favor net warming. However, the cooling effect is dominant with mid-level and low clouds, especially when they form in extensive sheets. Measurements by NASA indicate that on the whole, the effects of low and mid-level clouds that tend to promote cooling outweigh the warming effects of high layers and the variable outcomes associated with vertically developed clouds.
The Intergovernmental Panel on Climate Change (IPCC) assessment reports contain a summary of the current status of knowledge on the effect of cloud feedback on climate models. The IPCC Fourth Assessment Report (2007) stated:IPCC Fourth Assessment Report: Climate Change 2007: Working Group I: The Physical Science Basis, section 8.6.3.2 Clouds (2007). Accessed 18 June 2016. > By reflecting solar radiation back to space (the albedo effect of clouds) > and by trapping infrared radiation emitted by the surface and the lower > troposphere (the greenhouse effect of clouds), clouds exert two competing > effects on the Earth’s radiation budget.
PST, becoming the first American spacecraft to autonomously dock with the orbiting laboratory. March 8, 2019 – Crew Dragon splashed down in the Atlantic Ocean at 5:45 a.m. PST, completing the spacecraft's first mission to the International Space Station. January 19, 2020 – Crew Dragon test capsule was launched on a suborbital trajectory to conduct an in-flight abort test in the troposphere at transonic velocities, at max Q, where the vehicle experiences maximum aerodynamic pressure. The Crew Dragon splashed down at 15:38 UTC just off the Florida coast in the Atlantic Ocean.
Caribbean Winter Caribbean hurricanes are one of the most frequent natural disasters that impact the Caribbean. A hurricane is a tropical cyclone with sustained one-minute winds of at least 74 miles per hour. They are created when warm water hits the troposphere and high pressure pushes warm, dry air down in the center. This occurrence is particularly strong in the Caribbean due to the high amounts of humidity and warm air produce near perfect conditions to form these hurricanes, which are measured by the Saffir-Simpson scale and the Power Dispersion Index (PDI).
Liftoff of Crew Dragon In-Flight Abort Test. The Crew Dragon in-flight abort test was launched on 19 January 2020 at 15:30 UTC from Launch Complex 39A on a suborbital trajectory to conduct a separation and abort scenario in the troposphere at transonic velocities shortly after passing through max Q, where the vehicle experiences maximum aerodynamic pressure. The Dragon 2 used its SuperDraco abort engines to push itself away from the Falcon 9 after an intentional premature engine cutoff. Ten seconds after Dragon 2 was jettisoned, the Falcon 9 exploded and was destroyed.
Wildfire emissions contain fine particulate matter which can cause cardiovascular and respiratory problems. Increased fire byproducts in the troposphere can increase ozone concentration beyond safe levels. Forest fires in Indonesia in 1997 were estimated to have released between 0.81 and 2.57 gigatonnes (0.89 and 2.83 billion short tons) of CO2 into the atmosphere, which is between 13%–40% of the annual global carbon dioxide emissions from burning fossil fuels. In June and July of 2019, fires in the Arctic emitted more than 140 megatons of carbon dioxide, according to an analysis by CAMS.
A nimbostratus cloud is a multi-level, gray, often dark, amorphous, nearly uniform cloud that usually produces continuous rain, snow, or sleet but no lightning or thunder.Cloud in the Columbia Electronic EncyclopediaNimbostratus in the American Heritage DictionaryNimbostratus in the Oxford Dictionaries Online Although it is usually a low-based cloud, it actually forms most commonly in the middle level of the troposphere and then spreads vertically into the low and high levels. Nimbostratus usually produces precipitation over a wide area. Nimbo- is from the Latin word nimbus, which denotes precipitation.
Although altostratus forms mostly in the middle level of the troposphere, strong frontal lift can push it into the lower part of the high- level. The main high-level stratiform cloud is cirrostratus which is composed of ice crystals that often produce halo effects around the sun. Cirrostratus forms at altitudes of in high latitudes, in temperate latitudes, and in low, tropical latitudes. Of the non-stratiform clouds, cumulonimbus and cumulus congestus are the most closely related to nimbostratus because of their vertical extent and ability to produce moderate to heavy precipitation.
It is associated with ridging, or anticyclonic flow. In the low levels of the troposphere, outflow radiates from thunderstorms in the form of a wedge of rain-cooled air, which is visible as a thin rope-like cloud on weather satellite imagery or a fine line on weather radar imagery. For observers on the ground, a thunderstorm outflow boundary often approaches in otherwise clear skies as a low, thick cloud that brings with it a gust front. Low-level outflow boundaries can disrupt the center of small tropical cyclones.
Determining the nature of this seasonal variation is difficult because good data on Uranus's atmosphere has existed for less than one full Uranian year (84 Earth years). A number of discoveries have however been made. Photometry over the course of half a Uranian year (beginning in the 1950s) has shown regular variation in the brightness in two spectral bands, with maxima occurring at the solstices and minima occurring at the equinoxes. A similar periodic variation, with maxima at the solstices, has been noted in microwave measurements of the deep troposphere begun in the 1960s.
The Haleakalā Observatory, also known as the Haleakalā High Altitude Observatory Site, is Hawaii's first astronomical research observatory. It is located on the island of Maui and is owned by the Institute for Astronomy of the University of Hawai'i, which operates some of the facilities on the site and leases portions to other organizations. Tenants include the Air Force Research Laboratory (AFRL) and the Las Cumbres Observatory Global Telescope Network (LCOGTN). At over in altitude, the summit of Haleakalā is above one third of the Earths's troposphere and has excellent astronomical seeing conditions.
The basic concepts to study the atmosphere using light were developed before World War II. In 1930, E.H. Synge proposed to study the density of the upper atmosphere using a searchlight beam . In the following years, searchlight beams were used to study cloud altitude using both scanning and pulsed light.R. Bureau: La Météorologie 3, 292 (1946) Advanced techniques to study cloud properties using scattered light with different wavelengths were also proposed. With the first experiments, light scattering patterns were observed in the troposphere that were not compatible with a pure molecular atmosphere.
Cloud height is often related to the intensity of precipitation generated by a cloud: deeper clouds tend to produce more intense rainfall. For instance, cumulonimbus clouds can develop vertically through a substantial part of the troposphere and often result in thunderstorms with lightning and heavy showers. By contrast, very thin clouds (such as cirrus clouds) do not generate any precipitation at the surface of the Earth. For a synthetic discussion of the impact of clouds on the climate system, see the IPCC Third Assessment Report, in particular chapter 7.2.
The cooling in some regions is thought to have been as much as 0.5 °C (0.9 °F). An eruption the size of Mount Pinatubo tends to affect the weather for a few years; the material injected into the stratosphere gradually drops into the troposphere, where it is washed away by rain and cloud precipitation. A similar, but extraordinarily more powerful phenomenon occurred in the cataclysmic April 1815 eruption of Mount Tambora on Sumbawa island in Indonesia. The Mount Tambora eruption is recognized as the most powerful eruption in recorded history.
There are two definitions currently used for subtropical cyclones. Across the north Atlantic and southwest Indian Ocean, they require central convection fairly near the center and a warming core in the mid-levels of the troposphere. Across the eastern half of the northern Pacific, they require a mid-tropospheric cyclone to be cut off from the main belt of the westerlies and only a weak surface circulation. Subtropical cyclones have broad wind patterns with maximum sustained winds located farther from the center than typical tropical cyclones, and have no weather fronts linked into their center.
We think it probable that > this contained embedded within it a monoculture of infective 2019-nCoV virus > particles that survived in the interior of the incandescent meteor. We > consider the seemingly outrageous possibility that hundreds of trillions of > infective viral particles were then released embedded in the form of fine > carbonaceous dust. We believe infectious agents are prevalent in space, > carried on comets, and can fall towards Earth through the troposphere. > These, we think, can and have in the past gone on to bring about human > disease epidemics.
In a usual northern-hemisphere winter, several minor warming events occur, with a major event occurring roughly every two years. One reason for major stratospheric warmings to occur in the Northern hemisphere is because orography and land-sea temperature contrasts are responsible for the generation of long (wavenumber 1 or 2) Rossby waves in the troposphere. These waves travel upward to the stratosphere and are dissipated there, decelerating the westerly winds and warming the Arctic. This is the reason that major warmings are only observed in the northern-hemisphere, with two exceptions.
Temperature trends in two thick layers of the atmosphere as measured between January 1979 and December 2005 by Microwave Sounding Units and Advanced Microwave Sounding Units on NOAA weather satellites. The instruments record microwaves emitted from oxygen molecules in the atmosphere. Source: The division of the atmosphere into layers mostly by reference to temperature is discussed above. Temperature decreases with altitude starting at sea level, but variations in this trend begin above 11 km, where the temperature stabilizes through a large vertical distance through the rest of the troposphere.
The stratosphere, extending from the top of the troposphere to the bottom of the mesosphere, contains the ozone layer. The ozone layer ranges in altitude between 15 and 35 km, and is where most of the ultraviolet radiation from the Sun is absorbed. The top of the mesosphere, ranges from 50 to 85 km, and is the layer wherein most meteors burn up. The thermosphere extends from 85 km to the base of the exosphere at 400 km and contains the ionosphere, a region where the atmosphere is ionized by incoming solar radiation.
Atmospheric effects and societal consequences of regional scale nuclear conflicts and acts of individual nuclear terrorism. Atmospheric Chemistry and Physics 7:1973–2002 p. 1994 However, these efficient removal mechanisms in the troposphere are avoided in the Robock 2007 study, where solar heating is modeled to quickly loft the soot into the stratosphere, "detraining" or separating the darker soot particles from the fire clouds' whiter water condensation.Atmospheric effects and societal consequences of regional scale nuclear conflicts and acts of individual nuclear terrorism. Atmospheric Chemistry and Physics 7:1973–2002 pp.
Areas under and immediately adjacent to the downburst are the areas which receive the highest winds and rainfall, if any is present. Also, because the rain-cooled air is descending from the middle troposphere, a significant drop in temperatures is noticed. Due to interaction with the ground, the downburst quickly loses strength as it fans out and forms the distinctive "curl shape" that is commonly seen at the periphery of the microburst (see image). Downbursts usually last only a few minutes and then dissipate, except in the case of squall lines and derecho events.
Using the 850 and 700 hPa pressure surfaces, one can determine when and where warm advection (coincident with upward vertical motion) and cold advection (coincident with downward vertical motion) is occurring within the lower portions of the troposphere. Areas with small dewpoint depressions and are below freezing indicate the presence of icing conditions for aircraft. The 500 hPa pressure surface can be used as a rough guide for the motion of many tropical cyclones. Shallower tropical cyclones, which have experienced vertical wind shear, tend to be steered by winds at the 700 hPa level.
In 1956, Norman A. Phillips developed a mathematical model which could realistically depict monthly and seasonal patterns in the troposphere, which became the first successful climate model. Following Phillips's work, several groups began working to create general circulation models. The first general circulation climate model that combined both oceanic and atmospheric processes was developed in the late 1960s at the NOAA Geophysical Fluid Dynamics Laboratory. By the early 1980s, the United States' National Center for Atmospheric Research had developed the Community Atmosphere Model; this model has been continuously refined into the 2000s.
Seasonal average vertical columns of tropospheric ozone in Dobson units over the period 1979 to 2000. In June to August, photochemical ozone production causes very high concentrations over the East Coast of the US and China. Ozone (O3) is a trace gas of the troposphere, with an average concentration of 20–30 parts per billion by volume (ppbv), with close to 100 ppbv in polluted areas. Ozone is also an important constituent of the stratosphere, where the ozone layer exists which is located between 10 and 50 kilometers above the earths surface.
With the storm's eye becoming better defined, MFR upgraded Belna to a tropical cyclone early on 7 December. Hot towers were detected atop and within the storm's radius of maximum winds, suggesting the onset of a more accelerated rate of intensification. However, the presence of dry air in the mid-levels of the troposphere towards the storm's southeastern quadrant prevented Belna from developing considerably. At 18:00 UTC on 7 December, Belna's winds topped out at 155 km/h (100 mph) before fluctuating at a slightly lower strength over the ensuing day.
The ice crystals responsible for halos are typically suspended in cirrus or cirrostratus clouds in the upper troposphere (), but in cold weather they can also float near the ground, in which case they are referred to as diamond dust. The particular shape and orientation of the crystals are responsible for the type of halo observed. Light is reflected and refracted by the ice crystals and may split into colors because of dispersion. The crystals behave like prisms and mirrors, refracting and reflecting light between their faces, sending shafts of light in particular directions.
The dominance of particular bacteria and their nutrient sources are subject to change according to time and location. Bioaerosols can range in size from 10 nanometer virus particles to 100 micrometers pollen grains. Pollen grains are the largest bioaerosols and are less likely to remain suspended in the air over a long period of time due to their weight. Consequently, pollen particle concentration decreases more rapidly with height than smaller bioaerosols such as bacteria, fungi and possibly viruses, which may be able to survive in the upper troposphere.
Sulfur hexafluoride is inert in the troposphere and stratosphere and is extremely long-lived, with an estimated atmospheric lifetime of 800–3,200 years. Measurements of SF6 show that its global average mixing ratio has reached over 10 parts per trillion (ppt) as of April 2020, and is increasing by about 0.35 ppt (3.5 percent) per year. Average global SF6 concentrations increased by about seven percent per year during the 1980s and 1990s, mostly as the result of its use in magnesium production, and by electrical utilities and electronics manufacturers.
The resulting explosive volcanism probably ejected large amounts of dust and debris into the stratosphere causing major cooling (see volcanic winter). Climatic effects could also have been caused by sulphur ejected into the stratosphere, which rapidly converts to sulphuric acid, an aerosol which cools the troposphere by blocking incoming solar radiation. Another possible cause of the cat gap could have been the Late Cenozoic Ice Age that began 33.9 million years ago. This ice age caused glaciation in Antarctica that eventually spread to Arctic regions of southern Alaska, Greenland, and Iceland.
There is a significant connection between the carbon cycle and climate change. Most greenhouse gases are primarily composed of carbon and they produce an effect where warmer air that is heated by the sun is kept from leaving the atmosphere by forming a barrier in the troposphere. According to the Intergovernmental Panel on Climate Change, greenhouse gasses produced by human activity are the most significant cause of global climate change since the 1950s. Without human interaction, carbon is removed from and reintroduced to soil through a variety of ecosystem processes known as the carbon cycle.
About two thousand years ago, emissions of zinc from mining and smelting totaled 10 thousand tonnes a year. After increasing 10-fold from 1850, zinc emissions peaked at 3.4 million tonnes per year in the 1980s and declined to 2.7 million tonnes in the 1990s, although a 2005 study of the Arctic troposphere found that the concentrations there did not reflect the decline. Man-made and natural emissions occur at a ratio of 20 to 1. Zinc in rivers flowing through industrial and mining areas can be as high as 20 ppm.
There are a number of mechanisms of ice nucleation in the atmosphere through which ice nuclei can catalyse the formation of ice particles. In the upper troposphere, water vapor can deposit directly onto solid particle. In clouds warmer than about −37 °C where liquid water can persist in a supercooled state, ice nuclei can trigger droplets to freeze. Contact nucleation can occur if an ice nucleus collides with a supercooled droplet, but the more important mechanism of freezing is when an ice nucleus becomes immersed in a supercooled water droplet and then triggers freezing.
The concept of a pressure gradient is a local characterisation of the air (more generally of the fluid under investigation). The pressure gradient is defined only at these spatial scales at which pressure (more generally fluid dynamics) itself is defined. Within planetary atmospheres (including the Earth's), the pressure gradient is a vector pointing roughly downwards, because the pressure changes most rapidly vertically, increasing downwards (see vertical pressure variation). The value of the strength (or norm) of the pressure gradient in the troposphere is typically of the order of 9 Pa/m (or 90 hPa/km).
Schwarzschild's equation provides a simple explanation for the existence of the greenhouse effect and demonstrates that it requires a non-zero lapse rate.The requirement for a non-zero lapse rate is discussed on page 202 of Pierrehumbert. Rising air in the atmosphere expands and cools as the pressure on it falls, producing a negative temperature gradient in the Earth's troposphere. When radiation travels upward through falling temperature, the incoming radiation, I, (emitted by the warmer surface or by GHGs at lower altitudes) is more intense than that emitted locally by Bλ(T).
Hornbrook gave a presentation at the Gordon Research Conference where she presented a poster about VOC observations during the FRAPPE project in the Colorado Front Range. Prior to the FRAPPE project, Hornbrook worked on DC3 in Kansas, an airborne campaign which focused on how convective clouds interact with the upper troposphere at mid latitudes. Hornbrook's group observed that the storms observed possessed a logical relationship on a chemical level. In 2009, Hornbrook conducted research in Barrow, Alaska as part of the OASIS-2009 campaign (Ocean-Atmosphere-Sea Ice-Snowpack).
A mesoscale convective vortex (MCV), also known as a mesoscale vorticity center or Neddy eddy, is a mesocyclone within a mesoscale convective system (MCS) that pulls winds into a circling pattern, or vortex, at the mid levels of the troposphere and is normally associated with anticyclonic outflow aloft. With a core only wide and deep, an MCV is often overlooked in standard weather maps. MCVs can persist for up to two days after its parent mesoscale convective system has dissipated. The orphaned MCV can become the seed of the next thunderstorm outbreak.
To compare the MSU retrievals to the trend from the surface temperature record it is most appropriate to derive trends for the part of the atmosphere nearest the surface, i.e., the lower troposphere. As discussed earlier, the lowest of the temperature retrievals, TLT, is not a direct measurement, but a value calculated by subtracting higher altitude brightness temperature from the lower measurements. The trends found from the UAH and the RSS groups, shown in the table below, are calculated by slightly different methods, and result in different values for the trends.
She was the Director of the NSERC CREATE Training Program in Arctic Atmospheric Science, which ran from 2010 to 2016. This program provided students and postdoctoral fellows with training in Arctic atmospheric science. Strong founded the University of Toronto Atmospheric Observatory (TAO) in 2001, which monitors trace gasses in the stratosphere and troposphere from the roof of the McLennan Physical Laboratories Burton Tower at the University of Toronto. She is also the principal investigator of the Canadian Fourier transform infrared (FTIR) spectrometer Observing Network (CAFTON), which uses several monitoring stations across Canada, including TAO, to measure gasses and monitor changes in the atmosphere.
1: Formation of carbon-14 2: Decay of carbon-14 3: The "equal" equation is for living organisms, and the unequal one is for dead organisms, in which the C-14 then decays (See 2). Carbon-14 is produced in the upper layers of the troposphere and the stratosphere by thermal neutrons absorbed by nitrogen atoms. When cosmic rays enter the atmosphere, they undergo various transformations, including the production of neutrons. The resulting neutrons (1n) participate in the following n-p reaction: :n + → + p The highest rate of carbon-14 production takes place at altitudes of and at high geomagnetic latitudes.
Tropospheric propagation refers to the way radio signals travel through the lowest layer of the Earth's atmosphere, the troposphere, at altitudes up to about to 17 km (11 miles). Weather conditions in the lower atmosphere can produce radio propagation over greater ranges than normal. If a temperature inversion occurs, with upper air warmer than lower air, VHF and UHF radio waves can be refracted over the Earth's surface instead of following a straight-line path into space or into the ground. Such "tropospheric ducting" can carry signals for 800 km (500 miles) or more, far beyond usual range.
Large-scale release of sulphur dioxide into the troposphere also poses a potential health risk, especially to people with pre- existing breathing disorders. As of 15 April, the eruption was not large enough to have an effect on global temperatures like that of Mount Pinatubo and other major past volcanic eruptions.Sara Phillips "Icelandic volcano won't affect the world's climate" ABC, 16 April 2010. One previous related sequence of eruptions of this volcano, beginning in 1821 is recorded as having lasted for over two years, but no single set of major eruptions is known to have lasted more than 'several days'.
In areas where it is hilly or mountainous near the coastline, thermally-forced sea breezes combined with wind circulations up the sides of the mountains can encourage the production of chemicals which can lead to the development of smog. Pollution has been tracked into the mid-levels of the troposphere in the form of ozone, which is concentrated over the circulation of the thermal low as well as adjacent oceanic areas.A.C. Carvalho, A. Carvalho, I. Gelpi, M. Barreiro, C. Borrego, A.I. Miranda, V. Perez-Munuzuri (2006). Influence of topography and land use on pollutants dispersion in the Atlantic coast of Iberian Peninsula.
Identification of carbon in nuclear magnetic resonance (NMR) experiments is done with the isotope C. Carbon-14 (C) is a naturally occurring radioisotope, created in the upper atmosphere (lower stratosphere and upper troposphere) by interaction of nitrogen with cosmic rays. It is found in trace amounts on Earth of 1 part per trillion (0.0000000001%) or more, mostly confined to the atmosphere and superficial deposits, particularly of peat and other organic materials. This isotope decays by 0.158 MeV β emission. Because of its relatively short half-life of 5730 years, C is virtually absent in ancient rocks.
OSIRIS (Optical Spectrograph and InfraRed Imager System) is an instrument that measures vertical profiles of spectrally dispersed, limb scattered sunlight from the upper troposphere into the lower mesosphere. OSIRIS is one of two instruments on the Odin satellite, launched February, 2001 (the other instrument being a sub-mm radiometer) into a sun-synchronous, 6 pm/6 am local time orbit at 600 km. This restricts OSIRIS sunlit observations to the Northern hemisphere in May, June, July August and the Southern hemisphere in November, December, January and February. Global coverage from 82°S to 82°N occurs on the months adjoining the equinoxes.
Thunderstorm line viewed in reflectivity (dBZ) on a plan position indicator radar display The two major ways thunderstorms move are via advection of the wind and propagation along outflow boundaries towards sources of greater heat and moisture. Many thunderstorms move with the mean wind speed through the Earth's troposphere, the lowest of the Earth's atmosphere. Weaker thunderstorms are steered by winds closer to the Earth's surface than stronger thunderstorms, as the weaker thunderstorms are not as tall. Organized, long- lived thunderstorm cells and complexes move at a right angle to the direction of the vertical wind shear vector.
Conditions favorable for thunderstorm types and complexes There are four main types of thunderstorms: single-cell, multi-cell, squall line (also called multi-cell line) and supercell. Which type forms depends on the instability and relative wind conditions at different layers of the atmosphere ("wind shear"). Single-cell thunderstorms form in environments of low vertical wind shear and last only 20–30 minutes. Organized thunderstorms and thunderstorm clusters/lines can have longer life cycles as they form in environments of significant vertical wind shear, normally greater than in the lowest of the troposphere,Markowski, Paul and Yvette Richardson.
Any process that consumes methane from the atmosphere can be considered a "sink" of atmospheric methane. The most prominent of these processes occur as a result of methane either being destroyed in the atmosphere or broken down in soil. Humans have yet to act as any significant sink of atmospheric methane. A pie chart demonstrating the relative effects of various sinks of atmospheric methane Reaction with the hydroxyl radical – The major removal mechanism of methane from the atmosphere involves radical chemistry; it reacts with the hydroxyl radical (·OH) in the troposphere or stratosphere to create the ·CH3 radical and water vapor.
Radiative Processes in Meteorology and Climatology, Elsevier, Amsterdam, .), in the non-window wavenumbers, there is zero net exchange between the surface and the atmosphere, while, in the window wavenumbers, there is simply direct radiation from the land-sea surface to space. A like situation occurs between adjacent layers in the turbulently mixed boundary layer of the lower troposphere, expressed in the so-called "cooling to space approximation", first noted by Rodgers and Walshaw (1966).Rodgers, C.D., Walshaw, C.D. (1966). The computation of infrared cooling rate in planetary atmospheres, Quarterly Journal of the Royal Meteorological Society, 92: 67–92.
This also explains why moisture in the mid-levels of the troposphere, roughly at the 500 hPa level, is normally a requirement for development. However, when dry air is found at the same height, temperatures at 500 hPa need to be even colder as dry atmospheres require a greater lapse rate for instability than moist atmospheres. At heights near the tropopause, the 30-year average temperature (as measured in the period encompassing 1961 through 1990) was −77 °C (−132 °F). A recent example of a tropical cyclone that maintained itself over cooler waters was Epsilon of the 2005 Atlantic hurricane season.
Light aircraft or small commuter aircraft fly lower in the troposphere, not in the tropopause. Contrails and Cirrus clouds ; Water vapor (H₂O), and contrails : One of the products of burning hydrocarbons with oxygen is water vapour, a greenhouse gas. Water vapour produced by aircraft engines at high altitude, under certain atmospheric conditions, condenses into droplets to form condensation trails, or "contrails". Contrails are visible line clouds that form in cold, humid atmospheres and are thought to have a global warming effect (though one less significant than either CO₂ emissions or NOₓ induced effects).SPM-2 Contrails are uncommon from lower-altitude aircraft.
The imaging radars operated in three frequencies and four polarizations. This multispectral capability of the radars provided information about the Earth's surface over a wide range of scales not discernible with previous single-frequency experiments. The carbon monoxide sensor (MAPS) used gas filter radiometry to measure the global distribution of CO in the troposphere. Real time crew observations of surface phenomena and climatic conditions augmented with over 14,000 photographs aided investigators in interpretation and calibration of the data. The mission concluded on April 20, 1994, with a landing at Edwards Air Force Base after orbiting the Earth 183 times in 269 hours.
Almost all work to date on stratospheric sulfate injection has been limited to modelling and laboratory work. A Russian team tested aerosol formation in the lower troposphere using helicopters. The Stratospheric Particle Injection for Climate Engineering (SPICE) project planned on a limited field test in order to evaluate a potential delivery system, but this component of the project was canceled. In 2015, a group based at Harvard University has described a potential field experiment to test the possible damage to stratospheric ozone from stratospheric sulfate injection, and a first test is scheduled for 2019, taking place in the Tucson desert.
They decline deep in the troposphere with the rate of 3 m/s per km. The winds near the surface of Venus are much slower than that on Earth. They actually move at only a few kilometres per hour (generally less than 2 m/s and with an average of 0.3 to 1.0 m/s), but due to the high density of the atmosphere at the surface, this is still enough to transport dust and small stones across the surface, much like a slow-moving current of water. Meridional (north-south) component of the atmospheric circulation in the atmosphere of Venus.
Over the course of Saturn's 30-year orbit, Titan's cloud systems appear to manifest for 25 years, and then fade for four to five years before reappearing again. Cassini has also detected high-altitude, white, cirrus-type clouds in Titan's upper atmosphere, likely formed of methane. Although no evidence of lightning activity has yet been observed on Titan, computer models suggest that clouds in the moon's lower troposphere can accumulate enough charge to generate lightning from an altitude of roughly 20 km. The presence of lightning in Titan's atmosphere would favour the production of organic materials.
Commercial airliners typically cruise at altitudes of which is in the lower reaches of the stratosphere in temperate latitudes. This optimizes fuel efficiency, mostly due to the low temperatures encountered near the tropopause and low air density, reducing parasitic drag on the airframe. Stated another way, it allows the airliner to fly faster while maintaining lift equal to the weight of the plane. (The fuel consumption depends on the drag, which is related to the lift by the lift-to-drag ratio.) It also allows the airplane to stay above the turbulent weather of the troposphere.
According to the stories told by the elders on Orbis, the Doctor was said to have come from the bottom of the sea many years ago. As they shelter from the storm, Selta asks him to tell her his story, but before he can begin, the atmospheric scanner from the spaceship starts activating. There's just enough power left in the cells to reveal that the entire composition of the planet's troposphere is changing. The Doctor has lived on Orbis for longer than any of the current inhabitants and he knows this isn’t normal as the storm season should have ended months ago.
The vertical variation of geostrophic wind in a barotropic atmosphere (a) and in a baroclinic atmosphere (b). The blue portion of the surface denotes a cold region while the orange portion denotes a warm region. Cold cyclones are stronger aloft than at the Earth's surface, or stronger in areas of the troposphere with lower pressures, per the thermal wind relationship and the hypsometric equation. The hypsometric equation dictates that colder atmospheres have less room between pressure surfaces, which corresponds to the concept of lower atmospheric thickness, and the thermal wind relation indicates that in this situation, the wind increases with height.
Located east-southeast of Barbados, the twelfth depression of the season moved just north of due west, steered quickly at 20 to 25 mph (40 km/h) by a ridge of high pressure in the lower to middle troposphere. At 5 p.m. AST later on October 6, the NHC noted that the depression was nearing tropical storm strength. Shortly after, a burst of heavy convective thunderstorms developed over the ill-defined low-level center, and as organization improved, the system was upgraded to 40 mph (65 km/h) Tropical Storm Jerry around midnight on October 7.
Diagram showing an air parcel path when raised along B-C-E compared to the surrounding air mass Temperature (T) and humidity (Tw) In atmospheric sciences, the free convective layer (FCL) is the layer of conditional or potential instability in the troposphere. It is a layer in which rising air can experience positive buoyancy (PBE) so that deep, moist convection (DMC) can occur. On an atmospheric sounding, it is the layer between the level of free convection (LFC) and the equilibrium level (EL). The FCL is important to a variety of convective processes and to severe thunderstorm forecasting.
Conditions favorable for thunderstorm types and complexes There are four main types of thunderstorms: single-cell, multi-cell, squall line (also called multi-cell line) and supercell. Which type forms depends on the instability and relative wind conditions at different layers of the atmosphere ("wind shear"). Single-cell thunderstorms form in environments of low vertical wind shear and last only 20–30 minutes. Organized thunderstorms and thunderstorm clusters/lines can have longer life cycles as they form in environments of sufficient moisture, significant vertical wind shear (normally greater than in the lowest of the troposphere)Markowski, Paul and Yvette Richardson.
Baines took on the research topic of volcano dynamics in 2005, with a paper with RSJ Sparks on supervolcanic eruptions, and this was extended in 2008 to the effects of varying latitude on such large eruptions. In 2013 Baines, along with Selwyn Sacks, wrote an article entitled ‘Atmospheric internal waves generated by explosive volcanic eruptions’ for the UK Geological Society Memoirs volume on the Soufriere Hills volcano on Montserrat. This analysis followed barometric observations of this volcano that sporadically produces Vulcanian explosions spanning several minutes. The sudden addition of thermal energy results in the production of internal waves in the troposphere.
The resulting electrophilic bromonium cation (Br+) attacks hydrocarbons (symbolized as R-H in the following equation): :R-H + Br− \+ H2O2 → R-Br + H2O + OH− The bromination acts on a variety of dissolved organic matter and increasingly bromination leads to the formation of bromoform. The vanadium bromoperoxidases produce an estimated 1–2 million tons of bromoform and 56,000 tons of bromomethane annually. Partially in the polar regions, which has high blooms of microalgae in the spring, these compounds have the potential to enter the troposphere and lower stratosphere. Through photolysis, brominated methanes produce a bromine radical (Br−) that can lead to ozone depletion.
The Sahara High represents the eastern continental extension of the Azores High, centered over the North Atlantic Ocean. The subsidence of the Sahara High nearly reaches the ground during the coolest part of the year, while it is confined to the upper troposphere during the hottest periods. The effects of local surface low pressure are extremely limited because upper- level subsidence still continues to block any form of air ascent. Also, to be protected against rain-bearing weather systems by the atmospheric circulation itself, the desert is made even drier by its geographical configuration and location.
In fact, this so-called limb sounding technique allows us to determine the scale height, the constant describing the steepness of this atmospheric density decay. This makes the technique extremely valuable for climatological studies, as the scale height is directly related to the temperature in the upper atmosphere, where the limb sounding signals do their sensing. The technique works best in the lower stratosphere and upper troposphere; it breaks down close to the Earth surface especially in the tropics, due to water vapour extinction. Satellites involved in GPS limb sounding have been: METSAT, OERSTED (Danish), and several others.
A thumb Most of the Earth's weather and air pollution resides in the troposphere, the part of the atmosphere that extends from the surface of the planet to a height of about . The vertical lift of a severe thunderstorm or pyrocumulonimbus can be enhanced in the area of a large wildfire, which can propel smoke, soot, and other particulate matter as high as the lower stratosphere. Previously, prevailing scientific theory held that most particles in the stratosphere came from volcanoes, but smoke and other wildfire emissions have been detected from the lower stratosphere. Pyrocumulus clouds can reach over wildfires.
Satellite image of Earth cloud cover using NASA's Moderate- Resolution Imaging Spectroradiometer NASA photo showing the Earth's atmosphere, with the setting sun, with the Earth's landmass in shadow The atmospheric pressure at Earth's sea level averages , with a scale height of about . A dry atmosphere is composed of 78.084% nitrogen, 20.946% oxygen, 0.934% argon, and trace amounts of carbon dioxide and other gaseous molecules. Water vapor content varies between 0.01% and 4% but averages about 1%. The height of the troposphere varies with latitude, ranging between at the poles to at the equator, with some variation resulting from weather and seasonal factors.
In the troposphere, the picture is less clear but a significant part of the global tropospheric sulfate burden may be volcanogenic. Sulfate aerosol influences the Earth's radiation budget by scattering and absorption of shortwave and long-wave radiation, and by acting as cloud condensation nuclei. When they are brought to the boundary layer and Earth's surface, clouds containing volcanic sulfur in both gaseous and aerosol phases can result in profound environmental and health impacts. Examples of the environmental and health impacts are agricultural loss due to acid rain and particulate shading, damage to ecosystems, and pollution in the hydrosphere.
Terrestrial microwave relay links are limited in distance to the visual horizon, a few tens of miles or kilometers depending on tower height. Tropospheric scatter ("troposcatter" or "scatter") was a technology developed in the 1950s to allow microwave communication links beyond the horizon, to a range of several hundred kilometers. The transmitter radiates a beam of microwaves into the sky, at a shallow angle above the horizon toward the receiver. As the beam passes through the troposphere a small fraction of the microwave energy is scattered back toward the ground by water vapor and dust in the air.
As a result of the warmer climate and the sea level rise associated with the early Eocene, more wetlands, more forests, and more coal deposits would have been available for methane release. If we compare the early Eocene production of methane to current levels of atmospheric methane, the early Eocene would have produced triple the amount of methane. The warm temperatures during the early Eocene could have increased methane production rates, and methane that is released into the atmosphere would in turn warm the troposphere, cool the stratosphere, and produce water vapor and carbon dioxide through oxidation.
Mean July subtropical ridge position in North America The circulation around mid-level (altitude) ridges, and the air subsidence at their center, act to steer tropical cyclones around their periphery. Due to the subsidence within this type of system, a cap can develop which inhibits free convection and hence mixing of the lower with the middle level troposphere. This limits thunderstorm activity near their centers and traps low-level pollutants such as ozone as haze under their base, which is a significant problem in large urban centers during summer months such as Los Angeles, California and Mexico City.
Mesoscale meteorology is the study of atmospheric phenomena that has horizontal scales ranging from 1 km to 1000 km and a vertical scale that starts at the Earth's surface and includes the atmospheric boundary layer, troposphere, tropopause, and the lower section of the stratosphere. Mesoscale timescales last from less than a day to weeks. The events typically of interest are thunderstorms, squall lines, fronts, precipitation bands in tropical and extratropical cyclones, and topographically generated weather systems such as mountain waves and sea and land breezes.Online Glossary of Meteorology, American Meteorological Society , 2nd Ed., 2000, Allen Press.
In early July 1972, conditions across the western Pacific were highly favorable for tropical cyclogenesis. Enhanced by an El Niño event, surface westerlies traversed the region south of an east- west near-equatorial trough that extended from east of the Philippines to well east of the Marshall Islands. On July 3, conditions in the upper troposphere over the basin underwent significant changes with two upper-level troughs developing in the midlatitudes; of note was one which moved southward from Japan. By July 5, four distinct disturbances had organized along the near- equatorial trough; however, limited data made further analysis on these systems difficult.
Tronador () is an extinct stratovolcano in the southern Andes, located along the border between Argentina and Chile, near the Argentine city of Bariloche. The mountain was named Tronador (Spanish for "Thunderer") by locals in reference to the sound of falling seracs. With an altitude of , Tronador stands more than 1,000 m above nearby mountains in the Andean massif, making it a popular mountaineering destination. Located inside two national parks, Nahuel Huapi in Argentina and Vicente Pérez Rosales in Chile, Tronador hosts a total of eight glaciers, which are currently retreating due to warming of the upper troposphere.
The Great Dark Spot generated large white clouds at or just below the tropopause layer similar to high-altitude cirrus clouds found on Earth. Unlike the clouds on Earth, however, which are composed of crystals of ice, Neptune's cirrus clouds are made up of crystals of frozen methane. And while cirrus clouds usually form and then disperse within a period of a few hours, the clouds in the Great Dark Spot were still present after 36 hours, or two rotations of the planet. Neptune's dark spots are thought to occur in the troposphere at lower altitudes than the brighter upper cloud deck features.
The White Alice Communications System (WACS) was built in the mid-1950s to provide improved communications for the United States Air Force Alaskan Aircraft Control and Warning (AC&W;) radar stations. Communications were initially provided by a high frequency radio system which proved unreliable because of atmospheric disturbances in the high latitudes. AAC, after investigating various options, decided to build a system of Air Force-owned tropospheric scatter transmitters that bounced radio signals off the Troposphere, and microwave radio relay sites over short ranges of about 50 miles. The WACS provided these stations with reliable, quality telecommunications.
Emily V. Fischer is an Atmospheric Chemist and an Associate Professor in the Department of Atmospheric Science at Colorado State University. She earned notoriety from her work on the WE-CAN project and on PAN, specifically its role in changing the distribution of oxidants in the troposphere. She has received many honors including the prestigious James B. Macelwane Medal which is "given annually to three to five early career scientists in recognition of their significant contributions to Earth and space science." Fischer is also a role model and activist in galvanizing support for women in STEM fields.
Ash plume rising from Eyjafjallajökull on April 17, 2010 Sulfate aerosols promote complex chemical reactions on their surfaces that alter chlorine and nitrogen chemical species in the stratosphere. This effect, together with increased stratospheric chlorine levels from chlorofluorocarbon pollution, generates chlorine monoxide (ClO), which destroys ozone (O3). As the aerosols grow and coagulate, they settle down into the upper troposphere where they serve as nuclei for cirrus clouds and further modify the Earth's radiation balance. Most of the hydrogen chloride (HCl) and hydrogen fluoride (HF) are dissolved in water droplets in the eruption cloud and quickly fall to the ground as acid rain.
Anticyclonic flow aloft and a moist troposphere allowed the depression to intensity into Tropical Storm Sergio on November 14. Shortly after becoming a tropical storm, Sergio turned to the southeast, believed to be due to the flow associated with a mid- to upper-level trough to its northeast. It steadily intensified, and Sergio attained hurricane status on November 15 while located about 420 miles (675 km) southwest of Acapulco. With a small, distinct eye located in the center of the deep convection, Sergio rapidly intensified to attain peak winds of 110 mph (175 km/h) about 6 hours after becoming a hurricane.
The explosive stages of the 1669 eruption produced of pyroclastics and have been classified as category 2–3 on the Volcanic Explosivity Index, making it one of the most intense eruptions of Etna. Subplinian eruptions on Etna's flanks are not common; other examples are the prehistoric eruptions of Monte Moio 28,600 ± 4,700 years ago, Monte Frumento delle Concazze 3,500 years ago and Monte Salto del Cane 3,000 years ago. Over three million tons of sulfur were released by the eruption. This sulfur may have risen into the upper troposphere, causing changes in the chemistry of the regional atmosphere and environmental hazards.
In July, 1964, the 362n Signal Company had 216 Enlisted Men and 12 Officers. Operation Back Porch was the use of AN/MRC-85 Troposphere Scatter Microwave Communications Systems linking Saigon, Nha Trang, Quinhon and Danang, and linking Nha Trang to Pleiku and Ubon. The 362nd Signal also operated TRC-90 Microwave links joining Soc Trang to Vinh Long and Phulan, linking Phu Lam with Gia Nghia, Ban Me Thuot and Pleiku, linking Danang with Hue and Quang Ngai. The 362nd Signal was just about the first in and the last out of regular US Army company sized units deployed to South Vietnam.
This was the first instrument that was able to provide reliable temperature readings with high altitude balloons, as it was capable of shielding its thermometric elements from solar radiation. The technical implementation and production of this device took place in the factory of Rudolf Fuess (1838–1917). Threefold aspiration-psychrometer (Assmann type, prior to 1900) From 1888 to 1899, he was a member of the Vyerein zur Förderung der Luftschifffahrt, from which he organized scientific balloon ascents in order to study the atmosphere. From these studies, valuable insights in regards to atmospheric stratification of the troposphere were made.
On this day an unstable air mass, coming from the Southwest (Atlantic), associated with a depression, with expression in the high levels of the troposphere and the core centered to the West of Lisbon, brought some unsettled weather to Portugal, in particular to the region of Algarve which was hit by most of the storm cells that were moving inland. Embedded in this instability, Mesoscale Convective Systems developed with associated tornado activity being registered. One major tornado which caused significant damage to people's houses and cars among other structures was registered to have passed through Carvoeiro, Lagoa and Silves.
Meteorologists can extract information about the development stage and subsequent traits of thunderstorms by recognizing specific signatures in both domains. Visible imagery permits the most detailed imagery whereas infrared imagery has the advantage of availability at night. Sensors on satellites can also detect emissions from water vapor (WV: 6-7 µm), but mostly in the middle to upper levels of the troposphere, so thunderstorms are only seen after being well developed. It is, however, useful in convective storm prediction, as it illustrates the placement and movement of air masses and of moisture, as well as shortwaves and areas of vorticity and lifts.
Using the T2 or TMT channel (which include significant contributions from the stratosphere, which has cooled), Mears et al. of Remote Sensing Systems (RSS) find (through January 2017) a trend of +0.140 °C/decade. Spencer and Christy of the University of Alabama in Huntsville (UAH), find a smaller trend of +0.08 °C/decade. In comparing these measurements to surface temperature models, it is important to note that resulting values for the lower troposphere measurements taken by the MSU is a weighted average of temperatures over multiple altitudes (roughly 0 to 12 km), and not a surface temperature (see TLT in figure 3 above).
In comparing these measurements to surface temperature models, it is important to note that values for the lower troposphere measurements taken by the MSU are a weighted average of temperatures over multiple altitudes (roughly 0 to 12 km), and not a surface temperature (as seen in figure above). The results are thus not precisely comparable to surface temperature records or models. Pre-1998 results published by UAH showed no warming of the atmosphere. In a 1998 paper, Wentz and Schabel showed this (along with other discrepancies) was due to the orbital decay of the NOAA satellites.
While still at Harvard, Wennberg developed advanced airborne sensors to measure radicals in the atmosphere, in particular the odd-hydrogen radicals OH and HO2. The laser-induced fluorescence instrument that he developed was placed in the nose of a NASA ER-2 aircraft to measure radicals during flight. It has been used to measure radicals in both the troposphere and the stratosphere. Wennberg's sensor was used in several NASA missions, beginning with the SPADE mission in 1993. SPADE obtained the first simultaneous in situ measurements of OH, HO2, NO, NO2, ClO, and BrO from the lower stratosphere.
The data were used to calculate ozone loss rates and showed that HOx dominated stratospheric ozone loss, a result that had not been previously observable. NASA's ASHOE/MAESA mission (1994) took measurements of HOx from latitudes of -70°S to 70°N, reaching nearly from the south pole to the north pole. The STRAT mission (1995-1996) was the first to record measurements of HOx in the upper troposphere, and demonstrated that the concentration of HOx considerably exceeded expected levels. The POLARIS mission in 1997 obtained measurements all the way to 90° N latitude, the North pole.
The major use for skew-T log-P diagrams is the plotting of radiosonde soundings, which give a vertical profile of the temperature and dew point temperature throughout the troposphere and lower stratosphere. The isopleths on the diagram can then be used to simplify many tedious calculations involved, which were previously performed by hand or not at all. Many skew-T log-P diagrams also include a vertical representation of the wind speed and direction using wind barbs. Important atmospheric characteristics such as saturation, atmospheric instability, and wind shear are critical in severe weather forecasting, by which skew-T log-P diagrams allow quick visual analysis.
Balling has published much research pertaining to various factors that influence the Earth's climate. In 1988, Balling published a study which found that the construction of golf courses around Palm Springs, CA may have cooled the city over the preceding 15 years, in contrast to the warming effect usually associated with urban areas (also known as the urban heat island effect). Seven years later, Balling and Randall S. Cerveny, one of his ASU colleagues, published a study which found that the moon, when it is full, can cause Earth's troposphere to warm by more than 0.03 °F. However, it remained unclear why the moon might be able to do this.
The hypothesis, proposed by Vladimir Petoukhov, Stefan Rahmstorf, Stefan Petri, and Hans Joachim Schellnhuber, is that under some circumstances these waves interact to produce the static pattern. For this to happen, they suggest, the zonal (east-west) wave number of both types of wave should be in the range 6–8, the synoptic waves should be arrested within the troposphere (so that energy does not escape to the stratosphere) and mid-latitude waveguides should trap the quasistationary components of the synoptic waves. In this case the planetary-scale waves may respond unusually strongly to orography and thermal sources and sinks because of "quasiresonance". A 2017 study by Mann, Rahmstorf, et al.
For example, extensions of the Azores high pressure may bring about anticyclonic gloom during the winter, as they are warmed at the base and will trap moisture as they move over the warmer oceans. High pressures that build to the north and extend southwards will often bring clear weather. This is due to being cooled at the base (as opposed to warmed) which helps prevent clouds from forming. On weather maps, these areas show converging winds (isotachs), also known as confluence, or converging height lines near or above the level of non-divergence, which is near the 500 hPa pressure surface about midway up through the troposphere.
Vertical wind shear of less than 10 m/s (20 kt, 22 mph) between the surface and the tropopause is favored for tropical cyclone development. A weaker vertical shear makes the storm grow faster vertically into the air, which helps the storm develop and become stronger. If the vertical shear is too strong, the storm cannot rise to its full potential and its energy becomes spread out over too large of an area for the storm to strengthen. Strong wind shear can "blow" the tropical cyclone apart, as it displaces the mid-level warm core from the surface circulation and dries out the mid-levels of the troposphere, halting development.
The 8th partial lies at approximately 60 Hz. Observations of Schumann resonances have been used to track global lightning activity. Owing to the connection between lightning activity and the Earth's climate it has been suggested that they may also be used to monitor global temperature variations and variations of water vapor in the upper troposphere. It has been speculated that extraterrestrial lightning (on other planets) may also be detected and studied by means of their Schumann resonance signatures. Schumann resonances have been used to study the lower ionosphere on Earth and it has been suggested as one way to explore the lower ionosphere on celestial bodies.
In 1971, BAC's technical director was quoted as saying, "It is certain on present evidence and calculations that in the airport context, production Concordes will be no worse than aircraft now in service and will in fact be better than many of them."Aviation Daily, 18 February 1971, p. 263 Concorde produced nitrogen oxides in its exhaust, which, despite complicated interactions with other ozone-depleting chemicals, are understood to result in degradation to the ozone layer at the stratospheric altitudes it cruised. It has been pointed out that other, lower-flying, airliners produce ozone during their flights in the troposphere, but vertical transit of gases between the layers is restricted.
At the ground level, however, the movement of the air toward the equator in the lower troposphere deviates toward the west, producing a wind from the east. The winds that flow to the west (from the east, easterly wind) at the ground level in the Hadley cell are called the Trade Winds. Though the Hadley cell is described as located at the equator, in the northern hemisphere it shifts to higher latitudes in June and July and toward lower latitudes in December and January, which is the result of the Sun's heating of the surface. The zone where the greatest heating takes place is called the "thermal equator".
The largest-amplitude atmospheric tides are mostly generated in the troposphere and stratosphere when the atmosphere is periodically heated, as water vapor and ozone absorb solar radiation during the day. These tides propagate away from the source regions and ascend into the mesosphere and thermosphere. Atmospheric tides can be measured as regular fluctuations in wind, temperature, density and pressure. Although atmospheric tides share much in common with ocean tides they have two key distinguishing features: # Atmospheric tides are primarily excited by the Sun's heating of the atmosphere whereas ocean tides are excited by the Moon's gravitational pull and to a lesser extent by the Sun's gravity.
The complete sequence runs: "The Defenestration of Prague" → "Bohemia" → "Prokop the Great" → "Democracy" → "Yale Law School" → "Bill Clinton" → "Global Warming" → "Uncertainties" (see Uncertainty) → "Weather Forecasting" → "Troposphere" → "Turbulent" (see Turbulence) → "Golf Ball" → "Wooden" (see Wood) → "Particle Board" → "Stiletto Heels" → "Fetish" → "Castration Anxiety."Jeffrey O. Gustafson, 'Review: The Wikipedia Plays', The Signpost (6 August 2007). The play has been seen as belonging to a movement in contemporary theatre favouring long performances of sequential short plays, being compared with the Neo-Futurists' Too Much Light Makes the Baby Go Blind (1988), the work of the Reduced Shakespeare Company, and 365 Days/365 Plays by Suzan-Lori Parks (2006).
SUPARCO operates a national balloon launching facility in Karachi to conduct studies in atmospheric sciences to determine the vertical profile of ozone up to 30–35 km. This balloon sounding facility has been extensively used for carrying out research in better understanding of the meteorology and how the ozone layer vary seasonally in the stratosphere and troposphere. The Ionospheric Station at Karachi operates an Lonosonde observation facility, and recently the balloon flight mission was carried out by the station on 16 January 2004, up to an altitude of about 36 km to measure the vertical profile of the O3 trends. The maximum O3 observed 12.65 mPa at 27 km.
Antarctic composite image showing atmospheric motion vectors from the lower (yellow), middle (cyan), and upper (magenta) troposphere The AMRC updated its composite satellite imagery in 2014 which are derived from tests of atmospheric motion vectors. Currently, geostationary and polar-orbiting satellite observations can be used to generate wind vectors based on cloud motions or water vapor target movements over a series of three satellite images. However, the paths of the geostationary and polar-orbiting satellites leave a band of high latitudes not covered near the Antarctic and Southern Ocean. The AMRC generated atmospheric motion vectors to fill in these ‘rings’ of missing derived wind vectors.
The mixing ratio is much lower in the upper atmosphere due to the extremely low temperature at the tropopause, which lowers the saturation level and causes excess methane to freeze out. Methane appears to be undersaturated in the upper troposphere above the clouds having a partial pressure of only 30% of the saturated vapor pressure there. The concentration of less volatile compounds such as ammonia, water and hydrogen sulfide in the deep atmosphere is poorly known. However, as with methane, their abundances are probably greater than solar values by a factor of at least 20 to 30, and possibly by a factor of a few hundred.
This is a result of having temperatures and the pressures well above those of the critical points for hydrogen and helium, meaning that there is no sharp boundary between gas and liquid phases. Hydrogen becomes a supercritical fluid at a pressure of around 12 bar.Guillot (1999) Since the lower boundary of the atmosphere is ill-defined, the pressure level of 10 bars, at an altitude of about 90 km below 1 bar with a temperature of around 340 K, is commonly treated as the base of the troposphere. In scientific literature, the 1 bar pressure level is usually chosen as a zero point for altitudes—a "surface" of Jupiter.
Due to the anticipated convergence of favourable environmental parameters for development, MFR's tropical weather discussions began to highlight the possibility of a storm gradually developing in the eastern part of the South-West Indian Ocean basin on 9 February. A broad circulation in the lower troposphere and embedded within a monsoon trough began to take shape in this region on 12 February. The MFR designated the burgeoning system as a Zone of Disturbed Weather at 18:00 UTC on 13 February and began issuing advisories a day later. The presence of a subtropical ridge to Gabekile's east led to the storm taking a predominantly southward track.
The Concorde aircraft cruised at mach 2 at about , and the SR-71 cruised at mach 3 at , all within the stratosphere. Because the temperature in the tropopause and lower stratosphere is largely constant with increasing altitude, very little convection and its resultant turbulence occurs there. Most turbulence at this altitude is caused by variations in the jet stream and other local wind shears, although areas of significant convective activity (thunderstorms) in the troposphere below may produce turbulence as a result of convective overshoot. On October 24, 2014, Alan Eustace became the record holder for reaching the altitude record for a manned balloon at .
A 2005 study by Douglass and fellow University of Rochester physicist Robert S. Knox argued that global climate models underestimated the climate response to the 1991 eruption of Mount Pinatubo. The study also contended that global temperature returned to normal much faster after the eruption than the models had predicted. A 2007 paper by Douglass and coworkers questioned the reliability of 22 of the most commonly used global climate models analyzed by Benjamin D. Santer and used by the IPCC to predict accelerated warming in the troposphere. The study had originally been submitted to Geophysical Research Letters the previous year, but was rejected in September 2006 on Santer's recommendation.
An advantage of using remote sensing instruments over radiosondes for detection of the PBL height is the possibility of nearly continuous monitoring versus typical observations of twice per day from radiosondes. Continuous monitoring of PBL height will allow for a better understanding of the depth of convective turbulent processes in the ML which are a primary driver of air pollutants. The depth of the PBL is defined as the height of the inversion level separating the free troposphere (FT) from the boundary layer. Normally at the top of the PBL, buoyancy flux reaches a minimum and large gradients of potential temperature, water vapor, and aerosols are observed.
Executing a slow turn to the north and then the northwest, Gordon made two more landfalls, on eastern Jamaica and eastern Cuba. As Tropical Storm Gordon made its fourth landfall crossing the Florida Keys, it interacted with a cyclone in the upper troposphere and a series of cyclonic lows which lent the storm some sub- tropical characteristics. After a few days as an unusual hybrid of a tropical and a subtropical system in the Gulf of Mexico, the storm re-claimed its tropical storm status and it made another landfall across the Florida peninsula and continued into the Atlantic Ocean. In the Atlantic, Gordon rapidly strengthened to a Category 1 hurricane.
Due to the warming of the troposphere from the increased greenhouse effect of the polar stratospheric clouds, the stratosphere would cool and would potentially increase the amount of polar stratospheric clouds. While the polar stratospheric clouds could explain the reduction of the equator to pole temperature gradient and the increased temperatures at the poles during the early Eocene, there are a few drawbacks to maintaining polar stratospheric clouds for an extended period of time. Separate model runs were used to determine the sustainability of the polar stratospheric clouds. It was determined that in order to maintain the lower stratospheric water vapor, methane would need to be continually released and sustained.
As the storm continued into open waters of the Caribbean, the upper-level low gradually weakened and was replaced with an anticyclone. This allowed the storm to strengthen further, and on September 8, Edith became a hurricane in the south- central Caribbean Sea. On September 9, the storm rapidly intensified, and within 24 hours, Edith strengthened from a minimal hurricane to a powerful 160 mph (260 km/h) Category 5 hurricane just off the coast of Nicaragua. The cause for the explosive deepening is unknown, though it is speculated that the transformation in the upper troposphere from an upper-level low to an anticyclone led to a release of baroclinic energy.
During the cool season within the Northern Hemisphere, derechos generally develop within a pattern of mid- tropospheric southwesterly winds, in an environment of low to moderate atmospheric instability (caused by relative warmth and moisture near ground level, with cooler air aloft, as measured by convective available potential energy), and high values of vertical wind shear () within the lowest of the atmosphere). Warm season derechos in the Northern Hemisphere most often form in west to northwesterly flow at mid-levels of the troposphere, with moderate to high levels of thermodynamic instability. As previously mentioned, derechos favor environments of low-level warm advection and significant low-level moisture.
He originally aspired to be a naval architect, but was not admitted to the Webb Institute. He then turned to meteorology as a career and educational focus. As a doctoral student, while serving the remainder of his army commitment, he attended a lecture on weather forecasting conducted by Jule Charney, and asked a series of pointed questions during the question-and-answer session following the talk. Charney, a prominent atmospheric scientist, invited Smagorinsky to the Princeton, NJ Institute for Advanced Study to examine the possible predictability of large-scale motions in the middle troposphere (the lower part of the atmosphere) using the new electronic computer being designed by John von Neumann.
The first continued measurements of the stratosphere were taken by Richard Scherhag in 1951 using radiosondes to take reliable temperature readings in the upper stratosphere (~40 km) and he became the first to observe stratospheric warming on 27 January 1952. After his discovery, he assembled a team of meteorologists specifically to study the stratosphere at the Free University of Berlin and this group continued to map the northern-hemisphere stratospheric temperature and geopotential height for many years using radiosondes and rocketsondes. In 1979 when the satellite era began, meteorological measurements became far more frequent. Although satellites were primarily used for the troposphere they also recorded data for the stratosphere.
In the atmosphere, dinitrogen pentoxide is an important reservoir of the NOx species that are responsible for ozone depletion: its formation provides a null cycle with which NO and NO2 are temporarily held in an unreactive state. Mixing ratios of several ppbv have been observed in polluted regions of the night-time troposphere. Dinitrogen pentoxide has also been observed in the stratosphere at similar levels, the reservoir formation having been postulated in considering the puzzling observations of a sudden drop in stratospheric NO2 levels above 50 °N, the so-called 'Noxon cliff'. Variations in N2O5 reactivity in aerosols can result in significant losses in tropospheric ozone, hydroxyl radicals, and NOx concentrations.
At this point, models of the Earth's future environment demonstrate that the stratosphere would contain increasing levels of water. These water molecules will be broken down through photodissociation by solar UV, allowing hydrogen to escape the atmosphere. The net result would be a loss of the world's seawater by about 1.1 billion years from the present. There will be two variations of this future warming feedback: the "moist greenhouse" where water vapor dominates the troposphere while water vapor starts to accumulate in the stratosphere (if the oceans evaporate very quickly), and the "runaway greenhouse" where water vapor becomes a dominant component of the atmosphere (if the oceans evaporate too slowly).
In the northern hemisphere these patterns, known as the Brewer-Dobson circulation, make the ozone layer thickest in the spring and thinnest in the fall. When ozone is produced by solar UV radiation in the tropics, it is done so by circulation lifting ozone-poor air out of the troposphere and into the stratosphere where the sun photolyzes oxygen molecules and turns them into ozone. Then, the ozone-rich air is carried to higher latitudes and drops into lower layers of the atmosphere. Research has found that the ozone levels in the United States are highest in the spring months of April and May and lowest in October.
The flights offered a convenient means to study the stratification of the troposphere. Simultaneous measurements of temperature, pressure, and humidity could be combined with observations on horizontal and vertical wind movements and cloud formations and layering. However, the stratosphere was not discovered during this project, as the manned flights did not penetrate into this region, and because Aßmann thought that the temperature measurements from unmanned balloons above 10,000 m were an error caused by incomplete shielding from solar radiation. Aßmann eventually came to a different conclusion after a flight to 10,800 m by Berson and Süring on 31 July 1901 in the balloon Preussen, and a simultaneous unmanned flight.
After classified as an overland depression early on 8 March and moving further inland, it started to accelerated southwards the next day along the weakening mid-troposphere ridge on Madagascar, with deep convection rather far away from the ill-defined centre. Meanwhile, gale-force winds still maintained over the eastern coast throughout the inland period. Enawo emerged into the Indian Ocean late on 9 March and was considered as a post-tropical depression by Météo-France because of the asymmetric and shallow core. However, the JTWC started to issue a tropical cyclone warning on Enawo again due to a warm anomaly at 10 km altitude.
Ashes and aerosols in the troposphere are quickly removed by precipitation, but material injected into the stratosphere is much more slowly dispersed, in the absence of weather systems. Substantial amounts of stratospheric injection can have global effects: after Mount Pinatubo erupted in 1991, global temperatures dropped by about . The largest eruptions are thought to cause temperature drops down to several degrees, and are potentially the cause of some of the known mass extinctions. Eruption column heights are a useful way of measuring eruption intensity since for a given atmospheric temperature, the column height is proportional to the fourth root of the mass eruption rate.
In their report they outlined the system that would be built almost exactly. It called for eight major Sector Control Centres, numbered from 200 to 900, each of which control up to thirty unmanned radar sites for a total of 90 radar stations. Each of the radar stations consisted of a single tall mast with a number of small dishes in fixed positions on top (typically four, two pointed in either direction), with power and electronics located in a building below the mast. The sector control centres were linked using an advanced microwave communications system developed in part by CARDE, which scattered off the troposphere for long-distance communications.
Parcels of air traveling close to the sea surface take up heat and water vapor, the warmed air rises and expands and cools as it does so causes condensation and precipitation. The rising air, and condensation, produces circulatory winds that are propelled by the Coriolis force, which whip up waves and increase the amount of warm moist air that powers the cyclone. Both a decreasing temperature in the upper troposphere or an increasing temperature of the atmosphere close to the surface will increase the maximum winds observed in hurricanes. When applied to hurricane dynamics it defines a Carnot heat engine cycle and predicts maximum hurricane intensity.
Earth’s atmosphere consists of multiple layers with different temperature and density characteristics; common atmospheric models include the International Standard Atmosphere and the US Standard Atmosphere. A good approximation for many purposes is a polytropic troposphere of 11 km height with a lapse rate of 6.5 K/km and an isothermal stratosphere of infinite height (Garfinkel 1967), which corresponds very closely to the first two layers of the International Standard Atmosphere. More layers can be used if greater accuracy is required.The notes for Reed Meyer’s air mass calculator describe an atmospheric model using eight layers and using polynomials rather than simple linear relations for temperature lapse rates.
After graduating with her Bachelor of Education in Chemistry and Mathematics as well as her Bachelor of Science in Chemistry with honors in atmospheric chemistry, Hornbrook began her Doctor of Philosophy in Chemistry at York University. Throughout her graduate education, she worked alongside Jochen Rudolph conducting research on Volatile organic compounds and their role in the chemistry of the troposphere. Hornbrook published a total of seven papers before graduating with her Ph.D in chemistry from York University in 2005. Hornbrook is the recipient of two Governor General's Academic Medals which are awarded to the student who graduates a Canadian school with the highest grades.
A good example of convective instability can be found in our own atmosphere. If dry mid-level air is drawn over very warm, moist air in the lower troposphere, a hydrolapse (an area of rapidly decreasing dew point temperatures with height) results in the region where the moist boundary layer and mid-level air meet. As daytime heating increases mixing within the moist boundary layer, some of the moist air will begin to interact with the dry mid- level air above it. Owing to thermodynamic processes, as the dry mid-level air is slowly saturated its temperature begins to drop, increasing the adiabatic lapse rate.
In the early 1950s arctic surroundings and weather conditions of northern Canada made construction and manning of HF and VHF radio or microwave relay stations almost impossible. However there was an urgent need of reliable data and communication facilities from the radarstations in the north to their control centers in the south. The initial phase was using tropospheric scatter radio communication (troposcatter). Powerful radio signals in the kiloWatt range were bounced off the troposphere onwards to distant receiving stations using gigantic ‘billboard’ like antennas picking up just a fraction of the transmitted signals which had been reflected back meaning that the antenna and equipment maintenance and alignment had to be executed very carefully.
The •OH species has a lifetime in the Earth atmosphere of less than one second. Understanding the role of •OH in the oxidation process of methane (CH4) present in the atmosphere to first carbon monoxide (CO) and then carbon dioxide (CO2) is important for assessing the residence time of this greenhouse gas, the overall carbon budget of the troposphere, and its influence on the process of global warming. The lifetime of •OH radicals in the Earth atmosphere is very short, therefore •OH concentrations in the air are very low and very sensitive techniques are required for its direct detection. Global average hydroxyl radical concentrations have been measured indirectly by analyzing methyl chloroform (CH3CCl3) present in the air.
Thick haze and smoke, originating from burning biomass in northeastern India and air pollution from large industrial cities in northern India, often concentrate inside the Ganges Basin. Prevailing westerlies carry aerosols along the southern margins of the steep-faced Tibetan Plateau to eastern India and the Bay of Bengal. Dust and black carbon, which are blown towards higher altitudes by winds at the southern faces of the Himalayas, can absorb shortwave radiation and heat the air over the Tibetan Plateau. The net atmospheric heating due to aerosol absorption causes the air to warm and convect upwards, increasing the concentration of moisture in the mid- troposphere and providing positive feedback that stimulates further heating of aerosols.
Wind shear has a significant effect on the control of aircraft during take-off and landing, and was a significant cause of aircraft accidents involving large loss of life within the United States. Sound movement through the atmosphere is affected by wind shear, which can bend the wave front, causing sounds to be heard where they normally would not, or vice versa. Strong vertical wind shear within the troposphere also inhibits tropical cyclone development, but helps to organize individual thunderstorms into living longer life cycles that can then produce severe weather. The thermal wind concept explains how differences in wind speed with height are dependent on horizontal temperature differences, and explains the existence of the jet stream.
Isentropic analysis of the 300 Kelvin isotrope and the weather satellite image of clouds during a blizzard in Colorado Isentropic analysis in meteorology is a technique to find the vertical and horizontal motion of airmasses during an adiabatic process above the planetary boundary layer. The change of state of air parcels following isentropic surfaces does not involve exchange of heat with the environment. Such an analysis can also evaluate the airmass stability in the vertical dimension and whether an air parcel crossing such a surface will result in convective or stratiform clouds. It is based on the study of weather maps or vertical cross-sections of the potential temperature values in the troposphere.
On October 19, a tropical disturbance formed southeast of Yap, and the JMA mentioned the system as a tropical depression on October 21. On October 22, the PAGASA started to monitor the tropical depression and named it Ofel. On October 23, as the system started to increase in size, strong thunderstorms which were fragmented in a band that was wrapping loosely around the center of circulation, reaching high into the troposphere with cloud top temperatures are as cold as −63 Fahrenheit (−52 Celsius). On October 24, the storm made landfall over Leyte, as a tropical storm, with convection stretching over the entire republic, and the strongest convection remained to the east of the storm, over the Philippine Sea.
There are forces throughout the homosphere (which includes the troposphere, stratosphere, and mesosphere) that can impact the structural integrity of a cloud. It has been speculated that as long as the air remains saturated, the natural force of cohesion that hold the molecules of a substance together may act to keep the cloud from breaking up. However, this speculation has a logical flaw in that the water droplets in the cloud are not in contact with each other and therefore not satisfying the condition required for the intermolecular forces of cohesion to act. Dissolution of the cloud can occur when the process of adiabatic cooling ceases and upward lift of the air is replaced by subsidence.
Water vapor in saturated air is normally attracted to condensation nuclei such as salt particles that are small enough to be held aloft by normal circulation of the air. If the condensation process occurs below the freezing level in the troposphere, the nuclei help transform the vapor into very small water droplets. Clouds that form just above the freezing level are composed mostly of supercooled liquid droplets, while those that condense out at higher altitudes where the air is much colder generally take the form of ice crystals. An absence of sufficient condensation particles at and above the condensation level causes the rising air to become supersaturated and the formation of cloud tends to be inhibited.
Despite warm waters, persistent wind shear prevented significant strengthening. Executing a slow turn to the north and then the northwest, Gordon made two more landfalls, on eastern Jamaica and eastern Cuba, while delivering tremendous rains to western Hispaniola. As Gordon made its fourth landfall crossing the Florida Keys, it interacted with a cyclone in the upper-troposphere and a series of cyclonic lows which lent the storm some sub-tropical characteristics. After a few days as an unusual hybrid of a tropical and a subtropical system in the Gulf of Mexico, the storm re-claimed its fully tropical form and made yet another landfall, this time across the Florida peninsula, and continued into the Atlantic Ocean.
Global tropical cyclone tracks between 1985 and 2005, indicating the areas where tropical cyclones usually develop Tropical cyclogenesis is the development and strengthening of a tropical cyclone in the atmosphere. The mechanisms through which tropical cyclogenesis occurs are distinctly different from those through which temperate cyclogenesis occurs. Tropical cyclogenesis involves the development of a warm-core cyclone, due to significant convection in a favorable atmospheric environment. Tropical cyclogenesis requires six main factors: sufficiently warm sea surface temperatures (at least ), atmospheric instability, high humidity in the lower to middle levels of the troposphere, enough Coriolis force to develop a low-pressure center, a pre- existing low-level focus or disturbance, and low vertical wind shear.
By their very nature, indices are simple, and combine many details into a generalized, overall description of the atmosphere or ocean which can be used to characterize the factors which impact the global climate system. El Niño–Southern Oscillation (ENSO) is a coupled ocean-atmosphere phenomenon in the Pacific Ocean responsible for most of the global variability in temperature, and has a cycle between two and seven years. The North Atlantic oscillation is a mode of variability that is mainly contained to the lower atmosphere, the troposphere. The layer of atmosphere above, the stratosphere is also capable of creating its own variability, most importantly in the Madden–Julian oscillation (MJO), which has a cycle of approximately 30-60 days.
For late August standards, August 28 was a very humid, very warm day. Temperatures reached into the low 90s °F (32–34 °C; about 11 °F or 6 °C warmer than the normal of 79 °F – 26 °C), but dew points soared into the upper 70s °F (25–27 °C). The presence of such a high dew point did not necessarily predict a severe thunderstorm outbreak; the prior day, similar conditions existed in northern Illinois with the exception of a warmer mid level troposphere. A warmer atmosphere inhibits the rising of surface air through the atmosphere; a requirement for convective precipitation, that is, precipitation resultant from humid surface air ascending to condense in a cooler atmosphere above, to occur.
Because of the forces that affect tropical cyclone tracks, accurate track predictions depend on determining the position and strength of high- and low-pressure areas, and predicting how those areas will change during the life of a tropical system. The deep layer mean flow, or average wind through the depth of the troposphere, is considered the best tool in determining track direction and speed. If storms are significantly sheared, use of wind speed measurements at a lower altitude, such as at the 70 kPa pressure surface ( above sea level) will produce better predictions. Tropical forecasters also consider smoothing out short-term wobbles of the storm as it allows them to determine a more accurate long-term trajectory.
At VHF and higher frequencies, small variations (turbulence) in the density of the atmosphere at a height of around can scatter some of the normally line-of-sight beam of radio frequency energy back toward the ground. In tropospheric scatter (troposcatter) communication systems a powerful beam of microwaves is aimed above the horizon, and a high gain antenna over the horizon aimed at the section of the troposphere though which the beam passes receives the tiny scattered signal. Troposcatter systems can achieve over-the-horizon communication between stations apart, and the military developed networks such as the White Alice Communications System covering all of Alaska before the 1960s, when communication satellites largely replaced them.
Late on 13 April, a developing tropical low crossed over the 90th meridian east from the Australian cyclone region. The environment was generally favourable for tropical cyclogenesis, with warm sea surface temperatures, low vertical wind shear and good poleward upper-level outflow. Microwave satellite imagery indicated that formative convective banding had begun to wrap into the centre of circulation, and the JTWC assessed the probability of the system strengthening into a tropical cyclone as medium. However, MFR reported that there was a lack of substantial convergence from the north in the lower troposphere, which they noted could slow or prevent the development of a strong low-level circulation before environmental conditions became less favourable for strengthening.
Although Francisco's cloud pattern evolved into a central dense overcast, the 75 km/h (45 mph) 10-minute sustained wind assessed upon its upgrade to a tropical storm was ultimately the peak intensity of Francisco's first iteration. Northwesterly vertical wind shear accompanied by dry air in the mid-levels of the troposphere soon began to afflict the tropical storm, making its wind circulation increasingly ill- defined. The wind shear caused the bulk of Francisco's deep convection to shift southeast away from the center of circulation. Although gale-force winds were still present, Francisco was downgraded to a Zone of Disturbed Weather on 6 February as the circulation center became increasingly difficult to identify.
The upper layer of troposphere exhibits a phenomenon of super-rotation, in which the atmosphere circles the planet in just four Earth days, much faster than the planet's sidereal day of 243 days. The winds supporting super-rotation blow at a speed of 100 m/s (≈360 km/h or 220 mph) or more. Winds move at up to 60 times the speed of the planet's rotation, while Earth's fastest winds are only 10% to 20% rotation speed. On the other hand, the wind speed becomes increasingly slower as the elevation from the surface decreases, with the breeze barely reaching the speed of 10 km/h (2.8 m/s) on the surface.
The NHC remarked that Rosa's structure was well developed at the middle levels of the troposphere, with distinct rainbands wrapped around the southern semicircle of the cyclone. The hurricane leveled in intensity for eighteen hours before proceeding into another phase of rapid intensification; it reached major hurricane status at 18:00 UTC on September 27, peaking in intensity with maximum sustained winds of 150 mph (240 km/h) and a minimum central pressure of 936 mbar (27.64 inHg). This made Rosa the seventh Category4 hurricane of the year's season. After Rosa reached its peak, the hurricane's eyewall – an inner ring of clouds around the eye – began to warm considerably, signaling the start of an eyewall replacement cycle.
Image of an upper tropospheric cyclonic vortex in the western North Pacific, a cold-core low A cold-core low, also known as an upper level low or cold-core cyclone, is a cyclone aloft which has an associated cold pool of air residing at high altitude within the Earth's troposphere, without a frontal structure. It is a low pressure system that strengthens with height in accordance with the thermal wind relationship. If a weak surface circulation forms in response to such a feature at subtropical latitudes of the eastern north Pacific or north Indian oceans, it is called a subtropical cyclone. Cloud cover and rainfall mainly occurs with these systems during the day.
This can lead to downward motion because lifting of the air results in cooling that increases its density. All of these effects are subtly dependent on the vertical temperature and moisture structure of the atmosphere and result in major redistribution of heat that affect the Earth's climate. The complexity and diversity of clouds in the troposphere is a major reason for difficulty in quantifying the effects of clouds on climate and climate change. On the one hand, white cloud tops promote cooling of Earth's surface by reflecting shortwave radiation (visible and near infrared) from the sun, diminishing the amount of solar radiation that is absorbed at the surface, enhancing the Earth's albedo.
Uncertainties in methane emissions, including a history of so-called "super- emitters" and other unexplained atmospheric fluctuations, highlight the need for improved monitoring at both regional and global scale. Satellites have recently begun to come online with capability to measure methane and other more powerful greenhouse gases with improving resolution. The Tropomi instrument launched in year 2017 by the European Space Agency can measure methane, sulphur dioxide, nitrogen dioxide, carbon monoxide, aerosol, and ozone concentrations in earth's troposphere at resolutions of several kilometers. The CLAIRE satellite launched in year 2016 by the Canadian firm GHGSat can resolve carbon dioxide and methane to as little as 50 meters, thus enabling its customers to pinpoint the source of emissions.
Paluweh eruption as seen from space As per the above examples, while the Unzen eruptions have caused deaths and considerable local damage in the historic past, the impact of the June 1991 eruption of Mount Pinatubo was global. Slightly cooler-than-usual temperatures were recorded worldwide, with brilliant sunsets and intense sunrises attributed to the particulates; this eruption lofted particles high into the stratosphere. The aerosols that formed from the sulfur dioxide (SO2), carbon dioxide (CO2), and other gases dispersed around the world. The SO2 mass in this cloud—about 22 million tons—combined with water (both of volcanic and atmospheric origin) formed droplets of sulfuric acid, blocking a portion of the sunlight from reaching the troposphere and ground.
The role of solar activity in climate change has also been calculated over longer time periods using "proxy" datasets, such as tree rings. Models indicate that solar and volcanic forcings can explain periods of relative warmth and cold between AD 1000 and 1900, but human- induced forcings are needed to reproduce the late-20th century warming. Another line of evidence against the sun having caused recent climate change comes from looking at how temperatures at different levels in the Earth's atmosphere have changed. Models and observations (see figure above, middle) show that greenhouse gas results in warming of the lower atmosphere at the surface (called the troposphere) but cooling of the upper atmosphere (called the stratosphere).
Four similar trellised aerodynamic surfaces serve for stabilization. During the second and third stage of flight gas is injected into the diverging part of the nozzle for flight control. Launch-Assisting Support vehicle of Topol at the Saint- Petersburg Artillery Museum Troposphere Relay Station vehicle of Topol at the Saint-Petersburg Artillery Museum The missile is deployed in a Transporter Erector Launcher (TEL) canister mounted on cross-country 7-axle chassis on a mobile launch vehicle. The chassis incorporates jacks, gas and hydraulic drives and cylinders, with a power of several hundred tons, for jacking and leveling of the launcher, speeding up (combat) and slowing down (maintaining) elevation of the container with the missile in the vertical position.
Photolysis occurs in the atmosphere as part of a series of reactions by which primary pollutants such as hydrocarbons and nitrogen oxides react to form secondary pollutants such as peroxyacyl nitrates. See photochemical smog. The two most important photodissociation reactions in the troposphere are firstly: :O3 \+ hν -> O2 \+ O(1D) λ < 320 nm which generates an excited oxygen atom which can react with water to give the hydroxyl radical: :O(1D) + H2O -> 2 •OH The hydroxyl radical is central to atmospheric chemistry as it initiates the oxidation of hydrocarbons in the atmosphere and so acts as a detergent. Secondly the reaction: :NO2 \+ hν -> NO + O is a key reaction in the formation of tropospheric ozone.
El Salvador has earned the epithets endearment La Tierra de Soberbios Volcanes, (The Land of Magnificent Volcanoes). Cleveland Volcano in the Aleutian Islands of Alaska photographed from the International Space Station, May 2006 Large eruptions can affect ambient temperature as ash and droplets of sulfuric acid obscure the sun and cool the Earth's troposphere; historically, large volcanic eruptions have been followed by volcanic winters which have caused catastrophic famines. An eruption of Mount Pinatubo on June 12, 1991 three days before its climactic eruption Fountain of lava erupting from a volcanic cone in Hawaii, 1983 Barren Island, Andaman Islands, India, during an eruption in 1995. It is the only active volcano in South Asia.
Since the afternoon, Enawo started to significantly slow down with the weakening of the tropical ridge that drove the track southwards. Due to easterly vertical wind shear, the centre was located in the eastern part of deep convection. Enawo developed into a severe tropical storm at around 18:00 UTC on 4 March, displaying an impressive embedded centre pattern associated with extremely cold cloud tops. The JTWC indicated a system equivalent to Category 1 on the Saffir–Simpson scale at the same time. Météo-France upgraded Enawo to a tropical cyclone at 06:00 UTC on 5 March, after it resumed a west to west-southwest track steered by the mid- troposphere ridge south of Madagascar.
Other halogens (chlorine and iodine) are also activated through mechanisms coupled to bromine chemistry. The main consequence of halogen activation is chemical destruction of ozone, which removes the primary precursor of atmospheric oxidation, and generation of reactive halogen atoms/oxides that become the primary oxidizing species. The different reactivity of halogens as compared to OH and ozone has broad impacts on atmospheric chemistry, including near complete removal and deposition of mercury, alteration of oxidation fates for organic gases, and export of bromine into the free troposphere. Recent changes in the climate of the Arctic and state of the Arctic sea ice cover are likely to have strong effects on halogen activation and ODEs.
This research involves the use of seismography, analytical and numerical modeling efforts, and space geodetic techniques, such as laser ranging, artificial satellites, and interferometric observations of radio waves emanating from deep space. An important component of CIRES research in geodesy/geodynamics is participation in the multi- university consortium developed to assemble, test, and administer the deployment of instrument packages that use radio signals from Global Positioning System (GPS) satellites to determine distances between points on Earth's surface. The scientific objective is to monitor crustal deformation in tectonically active areas. Weather and Climate Dynamics Division (WCD) This division focuses on understanding how global processes are intertwined to create the weather and climate observed from the troposphere to the mesosphere.
Working at NOAA's Geophysical Fluid Dynamics Laboratory, first in Washington, DC and later in Princeton, New Jersey, Manabe worked with director Joseph Smagorinsky to develop three-dimensional models of the atmosphere. As the first step, Manabe and Wetherald (1967) developed one- dimensional, single-column model of the atmosphere in radiative-convective equilibrium with positive feedback effect of water vapor. Using the model, they found that, in response to the change in atmospheric concentration of carbon dioxide, temperature increases at the Earth's surface and in the troposphere, whereas it decreases in the stratosphere. The development of the radiative-convective model was a critically important step towards the development of comprehensive general circulation model of the atmosphere (Manabe et al. 1965).
Mather grew up in Bristol and was educated at the University of Cambridge where she was awarded a Master of Science (MSci) degree in 1999, a Master of Philosophy (MPhil) degree in 2000 and a Doctor of Philosophy degree in 2004. As an undergraduate she studied the Natural Sciences Tripos before switching to the History and Philosophy of Science for her MPhil (in the same MPhil class as Helen Macdonald (writer) and Katherine Angel). She spent a year working abroad before returning to science for her PhD which was completed in the Department of Earth Sciences and investigated the chemistry of volcanic plumes in the troposphere. Her PhD involved working in Chile, Nicaragua and Italy.
Once that happens, radiation can travel far enough that the local emission, Bλ(T), can differ from the absorption of incoming Iλ. Depending on what altitude the transition to semi-transparency occurs and the temperature gradient, dI for a layer of atmosphere can be negative (ordinary greenhouse effect) or positive (negative greenhouse effect). Since the vast majority of absorption and emission occurs in the troposphere, where a negative temperature gradient exists, the Earth's greenhouse effect makes the planet warmer than it would be otherwise. However, temperature rises with altitude in the lower stratosphere, and increasing CO2 there increases radiative cooling to space and is predicted to cause cooling above 14–20 km.
The leading area of a squall line is composed primarily of multiple updrafts, or singular regions of an updraft, rising from ground level to the highest extensions of the troposphere, condensing water and building a dark, ominous cloud to one with a noticeable overshooting top and anvil (thanks to synoptic scale winds). Because of the chaotic nature of updrafts and downdrafts, pressure perturbations are important. As thunderstorms fill into a distinct line, strong leading-edge updrafts – occasionally visible to a ground observer in the form of a shelf cloud – may appear as an ominous sign of potential severe weather. Beyond the strong winds because of updraft/downdraft behavior, heavy rain (and hail) is another sign of a squall line.
The amount of energy entering the troposphere and stratosphere from space weather phenomena is trivial compared to the solar insolation in the visible and infra-red portions of the solar electromagnetic spectrum. Although some linkage between the 11-year sunspot cycle and the Earth's climate has been claimed.,Variability of the solar cycle length during the past five centuries and the apparent association with terrestrial climate, K. Lassen and E. Friis-Christensen, 57, 8, pp. 835–845, 1995 this has never been verified. For example, the Maunder minimum, a 70-year period almost devoid of sunspots, has often been suggested to be correlated to a cooler climate, but these correlations have disappeared after deeper studies.
One of the major uncertainties in modeling the effects of the Arctic haze on the solar radiation balance was limited knowledge of the vertical distributions of black carbon. During 1983 and 1984 as part of the NOAA AGASP program, the first measurements of such distributions in the Arctic atmosphere were obtained with an aethalometer which had the capability of measuring black carbon on a real-time basis. These measurements showed substantial concentrations of black carbon found throughout the western Arctic troposphere including the North Pole. The vertical profiles showed either a strongly layered structure or an almost uniform distribution up to eight kilometers with concentrations within layers as large as those found at ground level in typical mid-latitude urban areas in the United States.
The visible scars from the impacts could be seen on Jupiter for many months. They were extremely prominent, and observers described them as even more easily visible than the Great Red Spot. A search of historical observations revealed that the spots were probably the most prominent transient features ever seen on the planet, and that although the Great Red Spot is notable for its striking color, no spots of the size and darkness of those caused by the SL9 impacts had ever been recorded before, or since. Spectroscopic observers found that ammonia and carbon disulfide persisted in the atmosphere for at least fourteen months after the collisions, with a considerable amount of ammonia being present in the stratosphere as opposed to its normal location in the troposphere.
The United States has the most tornadoes of any country. Many of these form in an area of the central (with some definitions including Southern) United States known as Tornado Alley. This area extends into Canada, particularly the Prairie Provinces and Ontario; however, activity in Canada is less frequent and intense than that of the US. The high frequency of tornadoes in North America is largely due to geography, as moisture from the Gulf of Mexico is easily advected into the midcontinent with few topographic barriers in the way. The Rocky Mountains block Pacific-sourced moisture and buckle the atmospheric flow, forcing drier air at mid-levels of the troposphere due to downsloping winds and causing cyclogenesis downstream to the east of the mountains.
This radiation interacts with atoms in the atmosphere to create an air shower of secondary radiation, including X-rays, muons, protons, alpha particles, pions, electrons, and neutrons. The immediate dose from cosmic radiation is largely from muons, neutrons, and electrons, and this dose varies in different parts of the world based largely on the geomagnetic field and altitude. For example, the city of Denver in the United States (at 1650 meters elevation) receives a cosmic ray dose roughly twice that of a location at sea level. This radiation is much more intense in the upper troposphere, around 10 km altitude, and is thus of particular concern for airline crews and frequent passengers, who spend many hours per year in this environment.
The Northern Hemisphere and the Southern Hemisphere each have a polar jet and a subtropical jet. The northern hemisphere polar jet flows over the middle to northern latitudes of North America, Europe, and Asia and their intervening oceans, while the southern hemisphere polar jet mostly circles Antarctica all year round. The southern hemisphere mid-latitude jet is a relatively narrow band of strong winds stretching from the Earth's surface to the top of the troposphere at about 12 km increasing steadily in strength with height. Jet streams are the product of two factors: the atmospheric heating by solar radiation that produces the large-scale Polar, Ferrel, and Hadley circulation cells, and the action of the Coriolis force acting on those moving masses.
The intensity of annular systems is typically greater than 83.5% of the maximum potential intensity, suggesting that the conditions in which storms gain annular characteristics are generally conducive for tropical cyclone persistence and intensification. Annular tropical cyclones also require low wind shear, and of the storms in the East Pacific and North Atlantic studied by Knaff and Kossin, all exhibited easterly winds and cold air in the upper troposphere. In addition to strong outflow, suggesting that the conditions that give rise to annular tropical cyclones are most optimal towards the equatorward side of a subtropical ridge and within the tropics. However, warmer sea surface temperatures (SSTs) are not required for annular tropical cyclones, with annular characteristics developing only within a narrow range of modest SSTs, ranging from .
The rotation period of the spot has decreased with time, perhaps as a direct result of its steady reduction in size. In 2010, astronomers imaged the GRS in the far infrared (from 8.5 to 24 μm) with a spatial resolution higher than ever before and found that its central, reddest region is warmer than its surroundings by between 3–4 K. The warm airmass is located in the upper troposphere in the pressure range of 200–500 mbar. This warm central spot slowly counter-rotates and may be caused by a weak subsidence of air in the center of GRS.Fletcher (2010), p. 306 The Great Red Spot's latitude has been stable for the duration of good observational records, typically varying by about a degree.
It was initially thought that tropical cyclones did not develop within the South Atlantic. Very strong vertical wind shear in the troposphere is considered a deterrent. The Intertropical Convergence Zone drops one to two degrees south of the equator, not far enough from the equator for the Coriolis force to significantly aid development. Water temperatures in the tropics of the southern Atlantic are cooler than those in the tropical north Atlantic. During April 1991, these assertions were proven false, when the United States' National Hurricane Center (NHC) reported that a tropical cyclone had developed over the Eastern South Atlantic. In subsequent years, a few systems were suspected to have the characteristics needed to be classified as a tropical cyclone, including in March 1994 and January 2004.
A wetbulb temperature at 500 hPa in a tropical atmosphere of is required to initiate convection if the water temperature is , and this temperature requirement increases or decreases proportionally by 1 °C in the sea surface temperature for each 1 °C change at 500 hpa. Under a cold cyclone, 500 hPa temperatures can fall as low as , which can initiate convection even in the driest atmospheres. This also explains why moisture in the mid-levels of the troposphere, roughly at the 500 hPa level, is normally a requirement for development. However, when dry air is found at the same height, temperatures at 500 hPa need to be even colder as dry atmospheres require a greater lapse rate for instability than moist atmospheres.
A tropospheric scatter NLOS link typically operates at a few gigahertz using potentially very high transmit powers (typically 3 kW to 30 kW, depending on conditions), very sensitive receivers and very high gain, usually fixed, large reflector antennas. The transmit beam is directed into the troposphere just above the horizon with sufficient power flux density that gas and water vapour molecules cause scattering in a region in the beam path known as the scatter volume. Some components of the scattered energy travel in the direction of the receiver antennas and form the receive signal. Since there are very many particles to cause scattering in this region, the Rayleigh fading statistical model may usefully predict behaviour and performance in this kind of system.
Note that in this simplification, the temperature is treated as constant, even though temperature also varies with height. However, the temperature variation within the lower layers of the atmosphere (troposphere, stratosphere) is only in the dozens of degrees, as opposed to their thermodynamic temperature, which is in the hundreds, so the temperature variation is reasonably small and is thus ignored. For smaller height differences, including those from top to bottom of even the tallest of buildings, (like the CN tower) or for mountains of comparable size, the temperature variation will easily be within the single-digits. (See also lapse rate.) An alternative derivation, shown by the Portland State Aerospace Society, is used to give height as a function of pressure instead.
CAPS, along with several other University of Oklahoma institutions, is a partner in a new Engineering Research Center led by the University of Massachusetts Amherst. The Engineering Research Center for Collaborative Adaptive Sensing of the Atmosphere (CASA) seeks to revolutionize the remote sensing of the lower troposphere, initially via inexpensive, low-power, phased array Doppler weather radars placed on cell towers and buildings. unique component of this project is that the sensors collaborate with one another and dynamically adjust their characteristics to sense multiple atmospheric phenomena while meeting multiple end user needs in an optimal manner. CAPS also is leading an NSF Large Information Technology Research (ITR) grant that seeks to develop an infrastructure for mesoscale meteorology research and education.
The Amundsen-Nobile Climate Change Tower (CCT) is a 34-meter research tower installed in Ny-Ålesund, Svalbard, Norway, for the study of various physical parameters in the boundary layer of the lower troposphere. In particular it continuously measured meteorological parameters (temperature, relative humidity, intensity and direction of the wind) at four different levels of height, and the four components of solar radiation and infrared at the top of the tower itself. They also measure the height of the layer of snow and its temperature at two depths. The tower was funded by the Department of Earth and Environment (DTA) of the National Research Council of Italy (CNR) and installed by Kings Bay in science village of Ny-Ålesund on Svalbard island.
When the Ozonolysis of Cholesterol reaction occurs, the atheronals as a product will quicken the normal conversion of monocytes to macrophages, are rapidly taken up by macrophages, hasten the inflammatory response on and increase the stickiness of the interior arterial walls, and contribute to the formation of arterial plaques. This cause Atherosclerosis, the hardening of the arteries. Atheronals possess biological effects that if translated to an in vivo setting could lead to the recruitment, entrapment, dysfunction, and ultimate destruction of macrophages, with the major leukocyte player in inflammatory artery disease. Furthermore, Atheronals have additionally been detected in lung tissue, potentially from exposure of lung surfactant to the troposphere. Furthermore, such cholesterol oxidation items have been found in the brains of autopsy specimens from Alzheimer’s patients.
On March 10, the FMS reported that Tropical Depression 11F had developed out of an area of low pressure that had spun down from the upper levels of the troposphere, about to the northeast of Rarotonga in the Southern Cook Islands. During the next day, shear decreased sufficiently to allow significant overall development. On the evening of the 11th, with the system moving into minimal shear, and outflow aloft becoming well-established, its probability of becoming a tropical cyclone in the next 12 hours was raised to high. At 111200 UTC, it was named Joni with 35 knots close to the centre and whilst located about 40 nautical miles west-northwest of Mangaia and about 70 miles east- southeast of Rarotonga.
Altocumulus is also commonly found between the warm and cold fronts in a depression, although this is often hidden by lower clouds. Towering altocumulus, known as altocumulus castellanus, frequently signals the development of thunderstorms later in the day, as it shows instability and convection in the middle levels of the troposphere (the lowest layer of the atmosphere), the area where towering cumulus clouds can turn into cumulonimbus. It is therefore one of three warning clouds often recorded by the aviation industry, the other two being towering cumulus and cumulonimbus. Altocumulus generally forms about above ground level, a similar level to altostratus formations, and satellite photography has revealed that the two types of cloud can create formations that can stretch for thousands of square miles.
Models simulating the effects of a supernova on the Earth, most notably gamma-ray bursts and X-ray flashes, indicate that the Earth would experience depletion of the ozone layer, increased UV exposure, global cooling, and nitrogen changes on the Earth's surface and in the troposphere. In addition to evidence of global cooling during the Younger Dryas, the presence of carbon-rich “black mats” around 30 cm in thickness across faunal and paleoindian hunting sites suggests that an abrupt change to more aquatic conditions occurred in a small time window. Brakenridge also discusses pollen-core research that suggests global cooling conditions did not only occur in northern latitudes, but also latitudes reaching 41°S. Tree-ring evidence shows an increase in cosmogenic 14C in ice cores.
Air composition, temperature, and atmospheric pressure vary with altitude, and air suitable for use in photosynthesis by terrestrial plants and breathing of terrestrial animals is found only in Earth's troposphere and in artificial atmospheres. Earth's atmosphere has changed much since its formation as primarily a hydrogen atmosphere, and has changed dramatically on several occasions—for example, the Great Oxidation Event 2.4 billion years ago, greatly increased oxygen in the atmosphere from practically no oxygen to levels closer to present day. Humans have also contributed to significant changes in atmospheric composition through air pollution, especially since industrialisation, leading to rapid environmental change such as ozone depletion and global warming. The atmosphere has a mass of about 5.15 kg,Lide, David R. Handbook of Chemistry and Physics.
On August 13, while located near the northwestern Bahamas, a substantial increase in convection resulted in the upper-level low building downwards to the middle levels of the troposphere, coinciding with the development of an upper level anticyclone. A closed low- level circulation nearly developed on August 14 to the east of Key Largo, Florida, but it weakened due to the deep convection remaining to the north over the mid-level center. The mid-level storm continued westward and moved across Florida. After crossing Florida, Hurricane Hunters indicated a poorly defined circulation, but with winds exceeding tropical storm strength, and the system was designated as Tropical Storm Erika late on August 14 while located 85 miles (135 km) west of Fort Myers.
Large, explosive volcanic eruptions inject water vapor (H2O), carbon dioxide (CO2), sulfur dioxide (SO2), hydrogen chloride (HCl), hydrogen fluoride (HF) and ash (pulverized rock and pumice) into the stratosphere to heights of 16–32 kilometres (10–20 mi) above the Earth's surface. The most significant impacts from these injections come from the conversion of sulfur dioxide to sulfuric acid (H2SO4), which condenses rapidly in the stratosphere to form fine sulfate aerosols. The SO2 emissions alone of two different eruptions are sufficient to compare their potential climatic impact. The aerosols increase the Earth's albedo—its reflection of radiation from the Sun back into space—and thus cool the Earth's lower atmosphere or troposphere; however, they also absorb heat radiated up from the Earth, thereby warming the stratosphere.
On August 8, the storm had developed an eye in a tightly wound spiral overcast and became a hurricane while moving westward. Cool inflow began to get trapped in the circulation, causing the hurricane to weaken to a storm on August 9, but due to the hurricane moving over warmer water, it was not enough to begin dissipation alone. The feeder bands, which helped the hurricane to reach its peak intensity, continued to persist over warm water until August 11, when the cirrus cap over Fernanda became uncoupled to the east, thus exposing the west side of the storm. Plane reports showed the hurricane had moved under westerly winds in the troposphere, which resulted in the storm weakening to a depression on August 13.
The freezing of organic matter in these aerosols promotes the formation of clouds in warmer and drier environments than where they would otherwise form, especially at high latitudes such as the North Atlantic Ocean. Organic matter in these aerosols help nucleation of water droplets at these regions, yet plenty of unknowns remain, such as what fraction contain ice-freezing organic materials, and from what biological sources. Nevertheless, the role of phytoplankton blooms as a source of enhanced ice nucleating particles has been confirmed in laboratory experiments, implying the important role of these aerosols in cloud radiative forcing. Primary marine aerosols created through bubble-bursting emission have been measured in the North Atlantic during spring 2008 by the International Chemistry Experiment in the Arctic Lower Troposphere (ICEALOT).
As for water vapor, the tritium concentration was approximately one order of magnitude greater than surface seawater concentrations (ranging from 0.46 to 1.15 Bq/liter). Therefore, the water vapor tritium is not affected by the surface seawater concentration; thus, the high tritium concentrations in the vapor were concluded to be a direct consequence of the downward movement of natural tritium from the stratosphere to the troposphere (therefore, the ocean air showed a dependence on latitudinal change). In the North Pacific Ocean, the tritium (introduced as bomb tritium in the Northern Hemisphere) spread in three dimensions. There were subsurface maxima in the middle and low latitude regions, which is indicative of lateral mixing (advection) and diffusion processes along lines of constant potential density (isopycnals) in the upper ocean.
Areas worldwide where tornadoes are most likely, indicated by orange shading The United States has the most tornadoes of any country, nearly four times more than estimated in all of Europe, excluding waterspouts. This is mostly due to the unique geography of the continent. North America is a large continent that extends from the tropics north into arctic areas, and has no major east-west mountain range to block air flow between these two areas. In the middle latitudes, where most tornadoes of the world occur, the Rocky Mountains block moisture and buckle the atmospheric flow, forcing drier air at mid-levels of the troposphere due to downsloped winds, and causing the formation of a low pressure area downwind to the east of the mountains.
Microbaroms that propagate up to the lower thermosphere may be carried in an atmospheric waveguide, refracted back toward the surface from below 120 km and above 150 km altitudes, or dissipated at altitudes between 110 and 140 km. They may also be trapped near the surface in the lower troposphere by planetary boundary layer effects and surface winds, or they may be ducted in the stratosphere by upper-level winds and returned to the surface through refraction, diffraction or scattering. These tropospheric and stratospheric ducts are only generated along the dominant wind directions, may vary by time of day and season, and will not return the sound rays to the ground when the upper winds are light. The angle of incidence of the microbarom ray determines which of these propagation modes it experiences.
In experimental work with Jonathan Toner to examine low temperature solutions of perchlorate salts, as found on Mars, Toner and Catling discovered that such solutions supercool and never crystallize. The perchlorates form glasses (amorphous solids) around -120 °C. Glasses are known to be far better for preserving microbes and biological molecules than crystalline salts, which could be relevant to the search for life on Mars, Jupiter's moon Europa, and Saturn's moon Enceladus. In the field of planetary atmospheres, David Catling and Tyler Robinson have proposed a general explanation for a curious observation: the minimum air temperature between the troposphere (the lowest atmospheric layer where temperature declines with altitude) and stratosphere (where temperature increases with altitude in an 'inversion') occurs a pressure of about 0.1 bar on Earth, Titan, Jupiter, Saturn, Uranus and Neptune.
Dmitry Medvedev during his visit to a regiment of the Strategic Rocket Forces equipped with Topol-M Combat Support Vehicle (MOBD) 15V231 of Topol/Topol-M at the Saint-Petersburg Artillery Museum Troposphere Relay Station R-406VCh of Topol/Topol-M at the Saint-Petersburg Artillery Museum The first stage has rocket motors developed by the Soyuz Federal Center for Dual-Use Technologies. These give the missile a much higher acceleration than other ICBM types. They enable the missile to accelerate to the speed of 7,320 m/s and to travel a flatter trajectory to distances of up to 10,000 km. As a solid propellant design, the missile can be maintained on alert for prolonged periods of time and can launch within minutes of being given the order.
However, in 1998, Wentz and Schabel determined that orbital decay had an effect on the derived temperatures. Hansen compared the corrected troposphere temperatures with the results of the published GISS model, and concluded that the model is in good agreement with the observations, noting that the satellite temperature data had been the last holdout of global warming denialists, and that the correction of the data would result in a change from discussing whether global warming is occurring to what is the rate of global warming, and what should be done about it. Hansen has continued the development and diagnostics of climate models. For instance, he has helped in the investigations of the decadal trends in tropopause height, which could be a useful tool for determining the human "fingerprint" on climate.
Jack's and Rapson's teams, along with NASA meteorologist Janet Tokada, build a forecast model based on Jack's research. A massive storm system develops in the northern hemisphere, splitting into three gigantic hurricane-like superstorms above Canada, Scotland, and Siberia. The storms pull frozen air from the upper troposphere into their center, flash-freezing anything caught in their eyes with temperatures below −150 degrees Fahrenheit (−101 degrees Celsius). Meanwhile, the weather worsens across the world: Tokyo is struck by a giant hail storm, Nova Scotia has a 25-foot (7 meters) storm surge in seconds, a three helicopter special task force tasked with rescuing the British Royal family from Balmoral Castle crashes in Scotland after all their fuel lines freeze, and Los Angeles is devastated by a tornado outbreak.
In 2010, Shaw wrote a paper entitled Downward wave coupling between stratosphere and troposphere: The important of meridional wave guiding and comparison with zonal-mean coupling. In 2017, Shaw worked on the paper Moist static energy framework for zonal-mean storm-track intensity. This paper showed that seasonal strength cannot be explained solely by seasonal changes in solar radiation, and that surface heat fluxes account for the muted seasonality in the Southern Hemisphere and large seasonality in the Northern Hemisphere, and in response to climate change surface heat fluxes over ocean versus land exert opposing influences on the strength of storm tracks. Shaw wrote Circulation response to warming shaped by radiative changes of clouds and water vapor (2015), which outlines how the atmosphere will manifest global climate change thru clouds and water vapor.
Presentation on imported dust in North American skies Large dust storm over Libya Atmospheric or wind-borne fugitive dust, also known as aeolian dust, comes from arid and dry regions where high velocity winds are able to remove mostly silt-sized material, deflating susceptible surfaces. This includes areas where grazing, ploughing, vehicle use, and other human activities have further destabilized the land, though not all source areas have been largely affected by anthropogenic impacts. One- third of the global land area is covered by dust-producing surfaces, made up of hyper-arid regions like the Sahara which covers 0.9 billion hectares, and drylands which occupy 5.2 billion hectares. Dust in the atmosphere is produced by saltation and sandblasting of sand-sized grains, and it is transported through the troposphere.
While the RSMC names each system, the main name list itself is coordinated among 18 countries that have territories threatened by typhoons each year. Within the northwestern Pacific, there are no official typhoon seasons as tropical cyclones form throughout the year. Like any tropical cyclone, there are few main requirements for typhoon formation and development: (1) sufficiently warm sea surface temperatures, (2) atmospheric instability, (3) high humidity in the lower to middle levels of the troposphere, (4) enough Coriolis effect to develop a low pressure center, (5) a pre-existing low level focus or disturbance, and (6) a low vertical wind shear. While the majority of storms form between June and November, a few storms do occur between December and May (although tropical cyclone formation is at a minimum during that time).
In nature, carbon exists as two stable, nonradioactive isotopes: carbon-12 (), and carbon-13 (), and a radioactive isotope, carbon-14 (), also known as "radiocarbon". The half-life of (the time it takes for half of a given amount of to decay) is about 5,730 years, so its concentration in the atmosphere might be expected to decrease over thousands of years, but is constantly being produced in the lower stratosphere and upper troposphere, primarily by galactic cosmic rays, and to a lesser degree by solar cosmic rays. These cosmic rays generate neutrons as they travel through the atmosphere which can strike nitrogen-14 () atoms and turn them into . The following nuclear reaction is the main pathway by which is created: : n + → + p where n represents a neutron and p represents a proton.
Electric blue is a color whose definition varies but is often considered close to cyan, and which is a representation of the color of lightning, an electric spark, and the color of ionized argon gas; it was originally named after the ionized air glow produced during electrical discharges, though its meaning has broadened to include shades of blue that are metaphorically "electric" by virtue of being "intense" or particularly "vibrant". Electric arcs can cause a variety of color emissions depending on the gases involved, but blue and purple are typical colors produced in the troposphere where oxygen and nitrogen dominate. The first recorded use of electric blue as a color name in English was in 1845.Maerz and Paul A Dictionary of Color New York:1930 McGraw- Hill, p.
In 2018, Hornbrook began to work as a part of the NASA ATom project which was part of the larger goal to prepare for the potential effects of global climate change. Her authored poster, as a result of the project, details the observations made of how the upper troposphere reacts with VOCs emitted by humans. WINTER was a 2015 project based out of northern Virginia that had an emphasis on looking at emissions in the northeastern United States and their effect on pollution over the region as well as the Atlantic Ocean. In 2013, Hornbrook contributed to the NOMADSS project which focused on looking at the effects of anthropogenic emissions in Chicago, Illinois and Gary, Indiana concluding that these emissions led to an increase of mercury in the area.
While the satellite data now show global warming, there is still some difference between what climate models predict and what the satellite data show for warming of the lower troposphere, with the climate models predicting slightly more warming than what the satellites measure. Both the UAH dataset and the RSS dataset have shown an overall warming trend since 1998, although the UAH retrieval shows slightly less warming than the RSS. In June 2017, RSS released v4 which significantly increased the trend seen in their data, increasing the difference between RSS and UAH trends.Major correction to satellite data shows 140% faster warming since 1998 Carbon Brief 30 June 2017 Atmospheric measurements taken by a different satellite measurement technique, the Atmospheric Infrared Sounder on the Aqua satellite, show close agreement with surface data.
At 1800 UTC that day, the depression intensified to moderate tropical storm intensity, thus receiving the name Bejisa by the Mauritius Meteorological Services. This coincided with the improving satellite appearance of the storm's central dense overcast. Intensification subsequently quickened, and at 0600 UTC the next day Bejisa was considered to be a severe tropical storm. Concurrently a strengthening ridge in the mid-levels of the troposphere began to steer the storm towards the south-southeast. Following the development of a small pinhole eye, Bejisa was upgraded to tropical cyclone status at 1200 UTC on December 30, followed by intense tropical cyclone status six hours thereafter, with peak winds of 165 km/h (105 mph). In addition, the JTWC estimated 1-minute winds of 195 km/h (120 mph), utilizing the Dvorak technique to estimate the intensity.
Elevated sea surface temperatures, contrasting with cold atmospheric air, encourage atmospheric instability, especially within the troposphere. In general, most Medicanes maintain a radius of , last between 12 hours and 5 days, travel between , develop an eye for less than 72 hours, and feature wind speeds of up to ; in addition, a majority are characterized on satellite imagery as asymmetric systems with a distinct round eye encircled by atmospheric convection. Weak rotation, similar to that in most tropical cyclones, is usually noted in a Medicane's early stages, increasing with intensity; Medicanes, however, often have less time to intensify, remaining weaker than most North Atlantic hurricanes and only persisting for the duration of a few days. The theoretical maximum potential intensity of Medicanes is equivalent to the lowest classification on the Saffir–Simpson hurricane wind scale, a Category 1 hurricane.
The convective planetary boundary layer (CPBL), also known as the daytime planetary boundary layer (or simply convective boundary layer, CBL, when in context), is the part of the lower troposphere most directly affected by solar heating of the earth's surface. This layer extends from the earth surface to a capping inversion that typically locates at a height of 1–2 km by midafternoon over land. Below the capping inversion (10-60% of CBL depth, also called entrainment zone in the daytime), CBL is divided into two sub-layers: mixed layer (35-80% of CBL depth) and surface layer (5-10% of CBL depth). The mixed layer, the major part of CBL, has a nearly constant distribution of quantities such as potential temperature, wind speed, moisture and pollutant concentration because of strong buoyancy generated convective turbulent mixing.
A diagram showing the relative positions of the Horse latitudes Horse latitudes, subtropical ridges or subtropical highs are the subtropical latitudes between 30 and 35 degrees both north and south where Earth's atmosphere is dominated by the subtropical high, an area of high pressure, which suppresses precipitation and cloud formation, and has variable winds mixed with calm winds. It is the product of the global air circulation cell known as the Hadley Cell. The subtropical ridge is characterized by mostly calm winds, which act to reduce air quality under its axis by causing fog overnight, and haze during daylight hours as a result of the stable atmosphere found near its location. The air descending from the upper troposphere flows out from its center at surface level toward the upper and lower latitudes of each hemisphere, creating both the trade winds and the westerlies.
The major objective of this flight was to validate the design and operating characteristics of Lidar in Space Technology Experiment (LITE) by gathering data about the Earth's troposphere and stratosphere. Additional objectives included the deploy and retrieval of SPARTAN-201, a free-flying satellite that investigated the physics of the solar corona, and the testing of a new EVA maneuvering device. The Shuttle Plume Impingement Flight Experiment (SPIFEX) was used to collect extensive data on the effects of jet thruster impingement, in preparation for proximity tasks such as space station docking. Mission duration was 10 days, 22 hours, 51 minutes. STS-78 Columbia, June 20 to July 7, 1996, Helms was the payload commander and flight engineer aboard Columbia, on the longest Space Shuttle mission to date (later that year the STS-80 mission broke its record by nineteen hours).
The combination of these two force balances is called thermal wind balance, a term generalizable also to more complicated horizontal flow balances such as gradient wind balance. Since the geostrophic wind at a given pressure level flows along geopotential height contours on a map, and the geopotential thickness of a pressure layer is proportional to virtual temperature, it follows that the thermal wind flows along thickness or temperature contours. For instance, the thermal wind associated with pole-to-equator temperature gradients is the primary physical explanation for the jet stream in the upper half of the troposphere, which is the atmospheric layer extending from the surface of the planet up to altitudes of about 12-15 km. Mathematically, the thermal wind relation defines a vertical wind shear – a variation in wind speed or direction with height.
Two kinds of large-scale atmospheric waves within the lower atmosphere exist internal waves with finite vertical wavelengths which can transport wave energy upward; and external waves with infinitely large wavelengths that cannot transport wave energy.Volland, H., "Atmospheric Tidal and Planetary Waves", Kluwer, Dordrecht, 1988 Atmospheric gravity waves and most of the atmospheric tides generated within the troposphere belong to the internal waves. Their density amplitudes increase exponentially with height so that at the mesopause these waves become turbulent and their energy is dissipated (similar to breaking of ocean waves at the coast), thus contributing to the heating of the thermosphere by about 250 K in eq.(2). On the other hand, the fundamental diurnal tide labeled (1, −2) which is most efficiently excited by solar irradiance is an external wave and plays only a marginal role within the lower and middle atmosphere.
Crutzen was also a leader in promoting the theory of nuclear winter. Together with John Birks he wrote the first publication introducing the subject: The atmosphere after a nuclear war: Twilight at noon (1982).Paul J. Crutzen and John W. Birks: The atmosphere after a nuclear war: Twilight at noon AMBIO, 1982 (abstract) They theorized the potential climatic effects of the large amounts of sooty smoke from fires in the forests and in urban and industrial centers and oil storage facilities, which would reach the middle and higher troposphere. They concluded that absorption of sunlight by the black smoke could lead to darkness and strong cooling at the earth's surface, and a heating of the atmosphere at higher elevations, thus creating atypical meteorological and climatic conditions which would jeopardize agricultural production for a large part of the human population.
At the 500 hPa level, the air temperature averages −7 °C (18 °F) within the tropics, but air in the tropics is normally dry at this level, giving the air room to wet-bulb, or cool as it moistens, to a more favorable temperature that can then support convection. A wetbulb temperature at 500 hPa in a tropical atmosphere of −13.2 °C is required to initiate convection if the water temperature is 26.5 °C, and this temperature requirement increases or decreases proportionally by 1 °C in the sea surface temperature for each 1 °C change at 500 hpa. Under a cold cyclone, 500 hPa temperatures can fall as low as −30 °C, which can initiate convection even in the driest atmospheres. This also explains why moisture in the mid-levels of the troposphere, roughly at the 500 hPa level, is normally a requirement for development.
Recognizing that a balance has to be struck between standards and completeness of ground-based measurement, the GCOS programme recognized a hierarchy of observational networks and systems, comprising comprehensive, baseline and reference networks based on assumptions of spatial sampling needs. An example of a particularly successful step forward in implementing a global observing system for climate is the initiation of a reference network for upper-air observations - the GCOS Reference Upper-Air Network (GRUAN). The network is the prototype of a hybrid observing system, combining operational upper-air measurement sites with research sites and providing high-quality reference data for atmospheric profiles. GRUAN sites are undertaking high-quality atmospheric profile measurements that will help understand trends in upper-air ECVs, assist in investigating processes in the upper-troposphere and lower stratosphere, and provide data for calibrating satellite measurements and validating independent climate analyses and models.
Water is also more chemically reactive, and can break down large organic molecules through hydrolysis. A life form whose solvent was a hydrocarbon would not face the risk of its biomolecules being destroyed in this way. In 2005, astrobiologist Chris McKay argued that if methanogenic life did exist on the surface of Titan, it would likely have a measurable effect on the mixing ratio in the Titan troposphere: levels of hydrogen and acetylene would be measurably lower than otherwise expected. In 2010, Darrell Strobel, from Johns Hopkins University, identified a greater abundance of molecular hydrogen in the upper atmospheric layers of Titan compared to the lower layers, arguing for a downward flow at a rate of roughly 1028 molecules per second and disappearance of hydrogen near Titan's surface; as Strobel noted, his findings were in line with the effects McKay had predicted if methanogenic life-forms were present.
The largest-amplitude atmospheric tides are mostly generated in the troposphere and stratosphere when the atmosphere is periodically heated as water vapour and ozone absorb solar radiation during the day. The tides generated are then able to propagate away from these source regions and ascend into the mesosphere and thermosphere. Atmospheric tides can be measured as regular fluctuations in wind, temperature, density and pressure. Although atmospheric tides share much in common with ocean tides they have two key distinguishing features: i) Atmospheric tides are primarily excited by the Sun's heating of the atmosphere whereas ocean tides are primarily excited by the Moon's gravitational field. This means that most atmospheric tides have periods of oscillation related to the 24-hour length of the solar day whereas ocean tides have longer periods of oscillation related to the lunar day (time between successive lunar transits) of about 24 hours 51 minutes.
CFC-113 is a very unreactive chlorofluorocarbon. It remains in the atmosphere about 90 years, sufficiently long that it will cycle out of the troposphere and into the stratosphere. In the stratosphere, CFC-113 can be broken up by ultraviolet radiation (where sunlight in the 190-225 nm (UV) range), generating chlorine radicals (Cl•), which initiate degradation of ozone requiring only a few minutes: :CFCl → CFCl + Cl• :Cl• + O → ClO• + O This reaction is followed by: :ClO• + O → Cl• + O The process regenerates Cl• to destroy more O. The Cl• will destroy an average of 100,000 O molecules during its atmospheric lifetime of 1–2 years. In some parts of the world, these reactions have significantly thinned the Earth's natural stratospheric ozone layer that shields the biosphere against solar UV radiation; increased UV levels at the surface can cause skin cancer or even blindness.
After release to the atmosphere, methane is removed by gradual oxidation to carbon dioxide and water by hydroxyl radicals () formed in the troposphere or stratosphere, giving the overall chemical reaction + 2 → + 2. While the lifetime of atmospheric methane is relatively short when compared to carbon dioxide, with a half-life of about 7 years, it is more efficient at trapping heat in the atmosphere, so that a given quantity of methane has 84 times the global- warming potential of carbon dioxide over a 20-year period and 28 times over a 100-year period. Natural gas is thus a potent greenhouse gas due to the strong radiative forcing of methane in the short term, and the continuing effects of carbon dioxide in the longer term. Targeted efforts to reduce warming quickly by reducing anthropogenic methane emissions is a climate change mitigation strategy supported by the Global Methane Initiative.
Hodograph plot of wind vectors at various heights in the troposphere, which is used to diagnose vertical wind shear Wind shear, sometimes referred to as wind gradient, is a difference in wind speed and direction over a relatively short distance in the Earth's atmosphere. Wind shear can be broken down into vertical and horizontal components, with horizontal wind shear seen across weather fronts and near the coast, and vertical shear typically near the surface, though also at higher levels in the atmosphere near upper level jets and frontal zones aloft. Wind shear itself is a microscale meteorological phenomenon occurring over a very small distance, but it can be associated with mesoscale or synoptic scale weather features such as squall lines and cold fronts. It is commonly observed near microbursts and downbursts caused by thunderstorms, weather fronts, areas of locally higher low level winds referred to as low level jets, near mountains, radiation inversions that occur because of clear skies and calm winds, buildings, wind turbines, and sailboats.
A weak and disorganized Mediterranean tropical-like cyclone on 28 January 2009 The development of Medicanes often results from the vertical shift of air in the troposphere as well, resulting in a decrease in its temperature coinciding with an increase in relative humidity, creating an environment more conducive for tropical cyclone formation. This, in turn, leads to in an increase in potential energy, producing heat-induced air-sea instability. Moist air prevents the occurrence of convective downdrafts—the vertically downward movement of air—which often hinder the inception of tropical cyclones, and in such a scenario, wind shear remains minimal; overall, cold-core cut-off lows serve well for the later formation of compact surface flux-influenced warm- core lows such as Medicanes. The regular genesis of cold-core upper-level lows and the infrequency of Mediterranean tropical cyclones, however, indicate that additional unusual circumstances are involved the emergence of the latter.
Because the model used to derive the Simpson-Nakajima limit (a grey stratosphere in radiative equilibrium and a convecting troposphere) can determine the water concentration as a function of altitude, the model can also be used to determine the surface temperature (or conversely, amount of stellar flux) that results in a high water mixing ratio in the stratosphere. While this critical value of outgoing longwave radiation is less than the Simpson-Nakajima limit, it still has dramatic effects on a planet's climate. A high water mixing ratio in the stratosphere would overcome the effects of a cold trap and result in a "moist" stratosphere, which would result in the photolysis of water in the stratosphere that in turn would destroy the ozone layer and eventually lead to a dramatic loss of water through hydrodynamic escape. This climate state has been dubbed the moist greenhouse effect, as the end-state is a planet without water, though liquid water may exist on the planet's surface during this process.
Ward and Brownlee predict that there will be two variations of the future warming feedback: the "moist greenhouse" in which water vapor dominates the troposphere and starts to accumulate in the stratosphere and the "runaway greenhouse" in which water vapor becomes a dominant component of the atmosphere such that the Earth starts to undergo rapid warming, which could send its surface temperature to over , causing its entire surface to melt and killing all life, perhaps about three billion years from now. In both cases, the moist and runaway greenhouse states the loss of oceans will turn the Earth into a primarily-desert world. The only water left on the planet would be in a few evaporating ponds scattered near the poles as well as huge salt flats around what was once the ocean floor, much like the Atacama Desert in Chile or Badwater Basin in Death Valley. The small reservoirs of water may allow life to remain for a few billion more years.
Rong Fu is a Chinese-American climatologist, meteorologist, researcher, professor, and published author with more than 100 articles, books, and projects detailing changes that occur in Earth's atmosphere and how they affect climate, seasons, rainfall, and the like. Fu has been invited to present over 115 presentations and seminars, and has administered more than 32 projects that received over 11 million dollars in funding. The focus areas of Fu's research are convection; cloud and precipitation processes and their role in climate; atmospheric transport in the upper troposphere and lower stratosphere; the interaction between the atmosphere and ocean and terrestrial vegetation; satellite remote sensing applications and retrievals; the interaction between rainfall rates and the rainforest in regions of the Amazon rainforest; and drought prediction in states across the United States, including California and Texas. She is currently a professor in the Atmospheric and Oceanic Sciences Department at UCLA and the associate director of UCLA's Joint Institute for Regional Earth System Science and Engineering.
Colors range from blue (no clouds) to white (totally cloudy). Like a digital camera, MODIS collects information in gridded boxes, or pixels. Cloud fraction is the portion of each pixel that is covered by clouds. Colors range from blue (no clouds) to white (totally cloudy). (click for more detail) Although the local distribution of clouds can be significantly influenced by topography, the global prevalence of cloud cover in the troposphere tends to vary more by latitude. It is most prevalent in and along low pressure zones of surface tropospheric convergence which encircle the Earth close to the equator and near the 50th parallels of latitude in the northern and southern hemispheres. The adiabatic cooling processes that lead to the creation of clouds by way of lifting agents are all associated with convergence; a process that involves the horizontal inflow and accumulation of air at a given location, as well as the rate at which this happens.
Alt URL The JTWC indicated that the system had reached tropical storm strength on the Saffir-Simpson hurricane wind scale at 06:00 UTC, and gave it the designation Tropical Cyclone 16P. Six hours later, the system was officially upgraded to a Category 1 tropical cyclone and was assigned the name Nora by the BOM. alt= As Nora passed slowly to the north of the Wessel Islands in a weak steering environment, the already supportive environmental conditions became extremely favourable for strengthening. A co- located anticyclone in the upper troposphere provided excellent poleward and equatorward outflow channels for the system in an environment of low vertical wind shear, and sea surface temperatures and ocean heat content had both become favourably high. Alt URL Nora began to rapidly intensify, reaching Category 2 strength on the Australian scale at 00:00 UTC on 23 March as a primitive eye began to emerge on visible-light satellite imagery.
A study by Utah State University analyzed the natural and anthropogenic influences on the climate anomalies using simulations, and found that (a) northern India has experienced increasingly large rainfall in June since the late 1980s, (b) the increase in rainfall appears to be associated with a tendency in the upper troposphere towards amplified short waves, and (c) the phasing of such amplified short waves is tied to increased loading of green-house gases and aerosols. In addition, a regional modeling diagnosis attributed 60–90 % of rainfall amounts in the June 2013 event to post-1980 climate trends. Unprecedented destruction the rainfall witnessed in Uttarakhand state was also attributed, by environmentalists, to unscientific developmental activities undertaken in recent decades contributing to high level of loss of property and lives. Roads constructed in haphazard style, new resorts and hotels built on fragile river and more than 70 hydroelectric projects in the watersheds of the state led to a "disaster waiting to happen" as termed by certain environmentalists.
The 2013-2022 Planetary Science Decadal Survey identified a Saturn probe mission as a high priority mission target for the NASA New Frontiers program due to the need for in-situ measurements to depths of 10 bars or more. The SPRITE team explains that "to develop an improved understanding of the formation, evolution, and structure of the Solar System, it is essential that the role played by the giant planets be well understood, and this cannot be accomplished without in-situ measurements of the composition, structure, dynamics, and processes of Saturn's atmosphere." In order to accomplish this, the mission scientists have set two main goals: # Collect and analyze evidence of Saturn’s formation and early evolution. ## Obtain a chemical inventory of Saturn's troposphere to distinguish between competing planet formation models and extent of migration in the early Solar System ## Constrain Saturn’s helium depletion to reconcile observed temperatures with thermal evolution models # Reveal the truth beneath Saturn’s clouds.
Convective outlook from the Storm Prediction Center highlighting a moderate risk of severe weather over North Texas on March 28 Early on March 28, an upper-level low tracked eastward into the Southern United States along with its associated shortwave trough, sending the subtropical jet through Texas and bringing along with it strong west- northwesterly winds in the upper-levels of the troposphere. Concurrently, a cold front extended zonally tracked south across the Great Plains before eventually stalling near the Red River valley, providing an additional focus area for storm development. Favorable conditions for severe weather were expected ahead of the upper-level low over areas of North Texas; accordingly, the Storm Prediction Center (SPC) issued a moderate risk for severe weather for the region, citing an unstable atmosphere caused by steep lapse rates of 7.5-8.0 °C/km and high convective available potential energy values. The environment was expected to be conducive for the development of supercells as the warped subtropical jet produced strong wind shear over Texas.
The 1995 "medicane" at 1015 UTC on 16 January, shortly after tropical cyclogenesis Among numerous documented Medicanes, the cyclone of January 1995, which was dubbed Celeno, is generally considered to be the best-documented instance in the 20th century. Emerging off of the Libyan coast into the central Mediterranean Sea toward the Ionian shoreline of Greece on 13 January as a compact low-pressure area, the precursor low maintained winds reaching up to as it traversed the Ionian Sea, while the German research ship Meteor recorded winds of . Upon the low's approach near Greece, it began to envelop an area of atmospheric convection; meanwhile, in the middle troposphere, a trough extended from Russia to the Mediterranean, bringing with it extremely cold temperatures. Two low-pressure areas were present along the path of the trough, with one situated above Ukraine and the other above the central Mediterranean, likely associated with a low-level cyclone over western Greece. Upon weakening and dissipation on 14 January, a second low, the system which would evolve into the Mediterranean tropical cyclone, developed in its place on 15 January.
Cloud seeding, a form of weather modification, is the attempt to change the amount or type of precipitation that falls from clouds, by dispersing substances into the air that serve as cloud condensation or ice nuclei, which alter the microphysical processes within the cloud. The usual intent is to increase precipitation (rain or snow), but hail and fog suppression are also widely practiced in airports. Numerous experiments have been done with those two methods in the troposphere. At higher altitudes, NASA studied inducing noctilucent clouds in 1960 and 2009.Artificial cloud created at the edge of space 23 September 2009 Magazine issue 2727 New ScientistNight Time Artificial Cloud Study Using NASA Sounding Rocket September 9, 2009 (press release) In 1984 satellites from three nations took part in an artificial cloud experiment as part of a study of solar winds and comets.Success is reported for space triple play Spokane Chronicle - Aug 16, 1984 A European satellite released and ignited barium and copper oxide 43,000 miles in space to create a 2,000 mile mauve and green plume visible for 22 minutes.
In 2020, a study showed that the process of relaxation (adjustment) of localized large-scale pressure anomalies in the lower equatorial troposphere, generates structures strongly resembling the Madden Julian Oscillation (MJO) events, as seen in vorticity, pressure, and moisture fields. Indeed it is demonstrated that baroclinicity and moist convection substantially change the scenario of the quasi-barotropic “dry” adjustment, which was established in the framework of one-layer shallow water model and consists, in the long-wave sector, in the emission of equatorial Rossby waves, with dipolar meridional structure, to the West, and of equatorial Kelvin waves, to the East. If moist convection is strong enough, a dipolar cyclonic structure, which appears in the process of adjustment as a Rossby-wave response to the perturbation, transforms into a coherent modon- like structure in the lower layer, which couples with a baroclinic Kelvin wave through a zone of enhanced convection and produces, at initial stages of the process, a self-sustained slowly eastward-propagating zonally- dissymmetrical quadrupolar vorticity pattern.
Satellite image of a tropical-like cyclone on 15 December 2005 Due to the confined character of the Mediterranean and the limited capability of heat fluxes—in the case of Medicanes, air—sea heat transfer—tropical cyclones with a diameter larger than cannot exist within the Mediterranean. Despite being a relatively baroclinic area with high temperature gradients, the primary energy source utilized by Mediterranean tropical cyclones is derived from underlying heat sources generated by the presence of convection—thunderstorm activity—in a humid environment, similar to tropical cyclones elsewhere outside the Mediterranean Sea. In comparison with other tropical cyclone basins, the Mediterranean Sea generally presents a difficult environment for development; although the potential energy necessary for development is not abnormally large, its atmosphere is characterized by its lack of moisture, impeding potential formation. The full development of a Medicane often necessitates the formation of a large-scale baroclinic disturbance, transitioning late in its life cycle into a tropical cyclone-like system, nearly always under the influence of a deep, cut-off, cold-core low within the middle-to-upper troposphere, frequently resulting from abnormalities in a wide-spreading Rossby wave—massive meanders of upper-atmospheric winds.
The key conclusions of Working Group I (The Scientific Basis, Summary for Policymakers, in ) were: #An increasing body of observations gives a collective picture of a warming world and other changes in the climate system (The global average surface temperature has increased over the 20th century by about 0.6 °C; Temperatures have risen during the past four decades in the lowest 8 kilometres of the atmosphere; Snow cover and ice extent have decreased) #Emissions of greenhouse gases and aerosols due to human activities continue to alter the atmosphere in ways that are expected to affect the climate (Anthropogenic aerosols (i.e., human emitted aerosols) are short-lived and mostly produce negative radiative forcing; Natural factors have made small contributions to radiative forcing over the past century) #Confidence in the ability of models to project future climate has increased (Complex physically based climate models are required to provide detailed estimates of feedbacks and of regional features. Such models cannot yet simulate all aspects of climate (e.g., they still cannot account fully for the observed trend in the surface-troposphere temperature difference since 1979) and there are particular uncertainties associated with clouds and their interaction with radiation and aerosols.
186 An NRC study panel on the topic met in December 1981 and April 1982 in preparation for the release of the NRC's The Effects on the Atmosphere of a Major Nuclear Exchange, published in 1985. As part of a study on the creation of oxidizing species such as NOx and ozone in the troposphere after a nuclear war,On the 8th Day – Nuclear Winter Documentary (1984) 21:40 launched in 1980 by AMBIO, a journal of the Royal Swedish Academy of Sciences, Paul J. Crutzen and John Birks began preparing for the 1982 publication of a calculation on the effects of nuclear war on stratospheric ozone, using the latest models of the time. However they found that in part as a result of the trend towards more numerous but less energetic, sub-megaton range nuclear warheads (made possible by the ceaseless march to increase ICBM warhead accuracy/Circular Error Probable), the ozone layer danger was "not very significant". It was after being confronted with these results that they "chanced" upon the notion, as "an afterthought" of nuclear detonations igniting massive fires everywhere and, crucially, the smoke from these conventional fires then going on to absorb sunlight, causing surface temperatures to plummet.

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