atmosphere

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atmosphere

(Academy Artworks)

1. The gaseous mass or envelope surrounding a celestial body, especially the one surrounding the earth, and retained by the celestial body's gravitational field.
2. The air or climate in a specific place.
3. (Abbr. atm) Physics. A unit of pressure equal to the air pressure at sea level. It equals the amount of pressure that will support a column of mercury 760 millimeters high at 0 degrees Celsius under standard gravity, or 14.7 pounds per square inch (1.01325 × 10⁵ pascals).
4. A dominant intellectual or emotional environment or attitude: an atmosphere of distrust among the electorate.
5. The dominant tone or mood of a work of art.
6. An aesthetic quality or effect, especially a distinctive and pleasing one, associated with a particular place: a restaurant with an Old World atmosphere.

[New Latin atmosphaera : Greek atmos, vapor + Latin sphaera, sphere; see sphere.]

A gaseous layer that envelops the Earth and most other planets in the solar system. Earth, Venus, Mars, Jupiter, Saturn, Uranus, Neptune, and Titan (Saturn's largest satellite) are all known to possess substantial atmospheres that are held by the force of gravity. The structure and properties of the various atmospheres are determined by the interplay of physical and chemical processes. Structural features of Earth's atmosphere detailed below can often be identified in the atmospheres of other planetary bodies. See also Planetary physics.

The composition of the Earth's atmosphere is primarily nitrogen (N₂), oxygen (O₂), and argon (Ar) [see table]. The concentration of water vapor (H₂O) is highly variable, especially near the surface, where volume fractions can vary from nearly 0% to as high as 4% in the tropics. There are many minor constituents or trace gases, such as neon (Ne), helium (He), krypton (Kr), and xenon (Xe), that are inert, and active species such as carbon dioxide (CO₂), methane (CH₄), hydrogen (H₂), nitrous oxide (NO), carbon monoxide (CO), ozone (O₃), and sulfur dioxide (SO₂), that play an important role in radiative and biological processes.

*Other gases, for example, CO, N₂O, NO₂, and many by-products of atmospheric pollution also exist in small amounts.

In addition to the gaseous component, the atmosphere suspends many solid and liquid particles. Aerosols are particulates usually less than 1 micrometer in diameter that are created by gas-to-particle reactions or are lifted from the surface by the wind. A portion of these aerosols can become centers of condensation or deposition in the growth of water and ice clouds. Cloud droplets and ice crystals are made primarily of water with some trace amounts of particles and dissolved gases. Their diameters range from a few micrometers to about 100 μm. Water or ice particles larger than about 100 μm begin to fall because of gravity and may result in precipitation at the surface. See also Aerosol; Cloud physics; Precipitation (meteorology).

One of the remarkable properties of the Earth's atmosphere is the large amount of free molecular oxygen in the presence of gases such as nitrogen, methane, water vapor, hydrogen, and others that are capable of being oxidized. The atmosphere is in a highly oxidizing state that is far from chemical equilibrium. This is in sharp contrast to the atmospheres of Venus and Mars, the planets closest to the Earth, which are composed almost entirely of the more oxidized state, carbon dioxide. The chemical disequilibrium on the Earth is maintained by a continuous source of reactive gases derived from biological processes. Life plays a vital role in maintaining the present atmospheric composition. See also Atmospheric chemistry; Mars; Venus.

The total mass of the Earth's atmosphere is about 5.8 × 10¹⁵ tons (5.3 × 10¹⁵ metric tons). The vertical distribution of gaseous mass is maintained by a balance between the downward force of gravity and the upward pressure gradient force. The balance is known as the hydrostatic balance or the barometric law. Hence, the declining atmospheric pressure that is measured while ascending in the atmosphere is a result of gravity. The globally averaged pressure at mean sea level is 1013.25 millibars (101,325 pascals).

Below about 60 mi (100 km) in altitude, the atmosphere's composition of major constituents is very uniform. This region is known as the homosphere to distinguish it from the heterosphere above 60 mi (100 km), where the relative amounts of the major constituents change with height. In the homosphere there are sufficient atmospheric motions and a short enough molecular free path to maintain uniformity in composition. Above the boundary between the homosphere and the heterosphere, known as the homopause or turbopause, the mean free path of the individual molecules becomes long enough that gravity is able to partially separate the lighter molecules from the heavier ones. The mean free path is the average distance that a particle will travel before encountering a collision. Hence the average molecular weight of the heterosphere decreases with height as the lighter atoms dominate the composition.

The vertical structure of the atmosphere is in large part determined by the transfer properties of the solar and terrestrial radiation streams. The energy of the smallest unit of radiation, the photon, is directly proportional to its frequency. The type of interaction that occurs between photons and the atmosphere depends on the energy of the photons. See also Photon.

The most energetic of the photons are x-rays and extreme ultraviolet radiation of the eletromagnetic spectrum, which are capable of dissociating and ionizing the gaseous molecules. The less energetic near-ultraviolet photons are able to excite molecules and atoms into higher electronic levels. As a result, most of the ultraviolet and x-ray radiation is attenuated by the upper atmosphere. A cloudless atmosphere, however, is relatively transparent to visible light, where most of the solar energy resides. At the opposite end of the spectrum toward the lower frequencies of radiation is the infrared part, which is capable of inducing various vibrational and rotational motions in triatomic and polyatomic molecules.

In order to maintain an energy balance, the Earth must emit about the same amount of radiation as it absorbs from the Sun. The terrestrial radiation occurs in the infrared part of the spectrum and hence is strongly affected by water vapor, clouds, carbon dioxide, and ozone and other trace gases. The ability of these gases to absorb and emit in the infrared allows them to effectively trap some of the outgoing radiation that is emitted by the surface, creating the so-called greenhouse effect. See also Insolation.

The atmospheric layer that extends from the surface to about 7 mi (11 km) is called the troposphere. The tropopause, which is the top of the troposphere, has an average altitude that varies from about 11 mi (18 km) near the Equator to about 5 mi (8 km) near the Poles. The actual tropopause height varies considerably on time scales from a few days to an entire year. The troposphere contains about 80% of the atmospheric mass and exhibits most of the day-to-day weather fluctuations that are observed from the ground. Temperatures generally decrease with increasing altitude at an average lapse rate of about 17°F/mi (6°C/km), although this rate varies considerably, depending on time and location. See also Tropopause; Troposphere.

The stratosphere is the atmospheric layer that extends from the tropopause up to the stratopause at about 30 mi (50 km) above the surface. It is characterized by a nearly isothermal layer in the first 6 mi (10 km) overlaid by a layer in which the temperature increases with height to a maximum of about 32°F (0°C) at the stratopause. The reversal in the temperature lapse rate is a result of direct absorption of solar radiation, mainly by ozone and oxygen at the ultraviolet frequencies. See also Stratosphere.

The reversal of the temperature lapse rate makes the stratosphere vertically stable. This stability limits the amount of vertical mixing and results in molecular residence times of many months to years. Another consequence of a stable stratosphere is that it acts as a lid on the troposphere, confining the strong vertical overturning and hence most of the surface-based weather phenomena. See also Weather.

The mesosphere is the atmospheric layer extending from the stratopause up to the mesopause at an altitude of about 53 mi (85 km). The mesosphere is characterized by temperatures decreasing with height at a rate of about 12°F/mi (4°C/km). Although the mesosphere has less vertical stability than the stratosphere, it is still more stable than the troposphere and does not experience rapid overturning. The coldest temperatures of the entire atmosphere are encountered at the mesopause, with values as low as −150°F (−100°C). The temperature lapse rate found in the mesosphere is a result of the gradual weakening with height of the direct absorption of solar radiation by ozone. The radiative infrared cooling to space by the carbon dioxide molecules is responsible for the low temperatures near the mesopause. See also Mesosphere.

The thermosphere is found above the mesopause. The thermosphere is characterized by rising temperatures with height up to an altitude of about 190 mi (300 km) and then is nearly isothermal above that. Although there is no clear upper limit to the thermosphere, it is convenient to consider it extending several thousand kilometers. Embedded within the thermosphere is the ionosphere, comprising those atmospheric layers in which the ionized molecules and atoms are dominating the processes.

Molecular species dominate the lower thermosphere, while atomic species are dominant above 190 mi (300 km). The distribution of the constituents is controlled by diffusive equilibrium in which the concentration of each constituent decreases exponentially with height according to its molecular weight. Hence the concentration of the heavier constituents such as nitrogen, oxygen, and carbon dioxide will decrease with height faster than the lighter constituents such as helium and hydrogen. At an altitude of 560 mi (900 km) helium becomes the dominant constituent while hydrogen dominates above 1900 mi (3000 km).

The ionosphere can be defined operationally as that part of the atmosphere that is sufficiently ionized to affect the propagation of radio waves. In the ionosphere, the dominant negative ion is the electron, and the main positive ions include O⁺, NO⁺, and O₂⁺. The ionosphere is classified into four subregions. The D region extends from 40 to 60 mi (60 to 90 km) and contains complex ionic chemistry; most of the ionization is caused by ultraviolet ionization of NO and by galactic cosmic rays. This region is responsible for the daytime absorption of radio waves, which prevents distant propagation of certain frequencies. The E region extends from 60 to 90 mi (90 to 150 km) and is caused primarily by the x-rays from the Sun. The F1 region from 90 to 125 mi (150 to 200 km) is caused by the extreme ultraviolet radiation from the Sun and disappears at night. Finally, the F2 region includes all the ionized particles above 125 mi (200 km), with the peak ion concentrations occurring near 190 mi (300 km). See also Cosmic rays; Ionosphere.

The exosphere is the atmosphere above 300 mi (500 km) where the probability of interatomic collisions is so low that some of the atoms traveling upward with sufficient velocity can escape the Earth's gravitational field. The dominant escaping atom is hydrogen since it is the lightest constituent. Calculations of the thermal escape of hydrogen (also known as the Jeans escape) yield a value of about 3 × 10⁸ atoms · cm⁻² · s⁻¹. This is a very small amount since at this rate less than 0.5% of the oceans would disappear over the current age of the Earth.

The magnetosphere is the region surrounding the Earth where the movement of ionized gases is dominated by the geomagnetic field. The lower boundary of the magnetosphere, which occurs at an altitude of nearly 75 mi (120 km), can be roughly defined as the height where there are enough neutral atoms that the ion-neutral particle collisions dominate the ion motion. The dynamics of the magnetosphere is dictated in part by its interaction with the plasma of ionized gases that blows away from the Sun, the solar wind. The solar wind interacts with the Earth's magnetic field and severely deforms it, producing a magnetosphere around the Earth. It extends about 40,000 mi (60,000 km) toward the Sun but extends beyond the orbit of the Moon away from the Sun. See also Magnetosphere; Solar wind; Van Allen radiation.

noun

1. The gaseous mixture enveloping the earth: air. See high/low, place.
2. A general impression produced by a predominant quality or characteristic: air, ambiance, aura, feel, feeling, mood, smell, tone. See be.
3. The totality of surrounding conditions and circumstances affecting growth or development: ambiance, climate, environment, medium, milieu, mise en scène, surroundings, world. See be, limited/unlimited, place.
4. A distinctive yet intangible quality deemed typical of a given thing: aroma, flavor, savor, smack. See taste/bad taste.

The natural body of air, composed of approximately 20% oxygen, 78% nitrogen, and 2% carbon dioxide and other gases, that covers the surface of the earth.

The earth's atmosphere is simple in some respects, and complex in others. It is relatively uniform in composition with respect to its major mass components (oxygen and nitrogen), yet extremely variable in some minor components, such as water vapor and ozone (O₃), which play major roles in its heat and radiation fluctuations. The atmosphere has a complex structure based on temperature gradients. This structure governs its mixing characteristics and the buildup of contaminants, yet is usually invisible, except when light-scattering particles suspended in the air make it visible. The structure of the atmosphere is of major importance to the dilution and dispersion of contaminants. It is governed by the lapse rate, which is the rate of change of air temperature with height above the ground.

The lowest of the atmospheric layers is the troposphere, which contains about 75 percent of the mass of the atmosphere, and almost all of its moisture. It extends to a height that varies from about 9 kilometers at the poles to about 15 kilometers at the equator, and it has an average lapse rate of about −6.5°C/km. The boundary between the troposphere and the next layer, the stratosphere, is known as the tropopause. The stratosphere contains essentially all of the remainder of the mass of the atmosphere; it is nearly isothermal (the temperature does not change with altitude) in the lower regions and shows a temperature increase with height in the upper regions. There is very little air exchange between the well-mixed and turbulent troposphere and the nearly stagnant stratosphere.

The major constituents of dry air at ground level are nitrogen (N₂) at 78.1 percent by volume, oxygen (O₂) at 21.0 percent, and argon (Ar) at 0.9 percent. Carbon dioxide (CO₂) is present at about 330 ppm by volume and methane (CH₄) at about1.5 ppm by volume. About 3 percent of the total mass of the lower atmosphere is water vapor (H₂O), but the concentration is extremely variable in both space and time. In general, the warmer portions of the atmosphere contain more water vapor. The water vapor content becomes lower with increasing altitude and with increasing latitude. Water vapor plays a critical role in governing the earth's heat exchange and the motion of the atmosphere, due to its high heat capacity, absorption of infrared radiation, and heat of vaporization. Further effects attributable to atmospheric water result when air motion creates clouds (aerosols of water droplets), in which the energy received as sunshine in one place is liberated as the latent heat of vaporization in another.

Of the incoming radiant energy, about 30 to 50 percent is scattered back toward space, reflected primarily by clouds and, to some extent, by solid particles or by the earth's surface. About 20 percent of the incident radiant energy is absorbed as it passes through the atmosphere. Stratospheric O₃ absorbs about 1 to 3 percent, primarily in the short-wave ultraviolet (UV) portion of the spectrum; this effectively limits further penetration to those wavelengths greater than 0.3 microns. In the troposphere, 17 to 19 percent of the incoming radiation is absorbed, due primarily to water vapor and secondarily to CO₂.

The average radiation into space essentially equals that absorbed from the sun, and a substantial amount of energy must flow from the tropics toward the poles within the oceans and the troposphere. This flow of energy is accomplished primarily by systems of warm air and ocean currents that flow toward the poles and cool currents that flow toward the tropics.

The dispersion of contaminants within the atmosphere is generally referred to as diffusion. For practical purposes, the dispersion of contaminants by molecular diffusion is negligible because the extent of movements are generally infinitesimal compared to the movements of the air volumes containing them by the turbulent motions of the air (turbulent diffusion).

Atmospheric turbulence is a complicated phenomenon that has defied mathematical description. When considering contaminant dispersion, contaminant sources can be divided into three different categories: (1) point sources, such as tall industrial smokestacks; (2) line sources, such as highways; and (3) area sources, such as whole urban regions. The simplest is an elevated point source. The light-scattering properties of the aerosol in the plume from such a stack, consisting of fly ash and condensed water, enable us to observe plume dispersion with the unaided eye.

The vertical mixing of air is dependent upon the temperature profile of the atmosphere (the lapse rate). The immediate ground level concentrations of air contaminants may be reduced by vertical mixing, since dispersal into higher regions dilutes the contaminants. Poor vertical mixing may allow concentrations released at low altitudes to remain there in relatively concentrated form. An extreme case of atmospheric stability occurs when the atmospheric lapse rate is negative (when the temperature increases with altitude). This condition is known as a temperature inversion. There is virtually no vertical air movement within inversion layers and contaminants accumulate within them.

(SEE ALSO: Airborne Particles; Ambient Air Quality [Air Pollution]; Climate Change and Human Health)

— MORTON LIPPMANN

n.the air enveloping the earth.

See the Introduction, Abbreviations and Pronunciation for further details.

1. The layer of air surrounding the Earth, with an average composition, by volume, of 79% nitrogen, 20% oxygen, 0.03% carbon dioxide, and traces of rare gases. This surprisingly uniform composition is achieved by convection in the turbosphere and by diffusion above it, especially above 100 km, where diffusion is rapid in the thin atmosphere, and stirring is weak. Also present are atmospheric moisture, ammonia, ozone, and salts and solid particles. The atmosphere is commonly divided into the troposphere, the stratosphere, and the ionosphere.

Since the troposphere contains the majority of the atmospheric mass, and virtually all of the atmospheric water vapour, most weather events occur within it.

2. A unit of air pressure; one atmosphere is equal to the pressure exerted by the weight of a column of 760 mm of mercury at 0 °C, under standard gravity, at sea level.

(click to enlarge)
In Earth's atmosphere, the limits of the atmospheric layers are approximate and variable, … (credit: © Merriam-Webster Inc.)

Gaseous envelope that surrounds the Earth. Near the surface it has a well-defined chemical composition (see air). In addition to gases, the atmosphere contains solid and liquid particles in suspension. Scientists divide the atmosphere into five main layers: in ascending order, the troposphere (surface to 6 – 8 mi, or 10 – 13 km); the stratosphere (4 – 11 mi, or 6 – 17 km, to about 30 mi, or 50 km); the mesosphere (31 – 50 mi, or 50 – 80 km); the thermosphere (50 – 300 mi, or 80 – 480 km); and the exosphere (from 300 mi and gradually dissipating). Most of the atmosphere consists of neutral atoms and molecules, but in the ionosphere a significant fraction is electrically charged. The ionosphere begins near the top of the stratosphere but is most distinct in the thermosphere. See also ozone layer.

For more information on atmosphere, visit Britannica.com.

1. Gases enveloping the Earth at sea level consisting of approximately 78% nitrogen. 20.95% oxygen, and 0.37% carbon dioxide, and variable amounts of water vapour.

2. Unit of pressure; one normal atmosphere equals 101 325 N m⁻².

Atm is the abbreviation for atmosphere, which in the wine world is the measurement for pressure used to produce sparkling wines. Technically, it's the normal air pressure at sea level, approximately 14.7 pounds per square inch. In the production of a standard sparkling wine such as champagne or spumante the pressure should be 6 atm. A crémant-style sparkling wine has about half that pressure, and some frizzante-style Italian wines may have only 2 atm of pressure.

The blanket of gas on the surface of a planet or satellite.

To convert from atmospheres to:

ton/sq. inch, multiply by 0.007348.
cms of mercury, multiply by 76.
ft. of water (at 4 degrees C), multiply by 33.9.
in. of mercury (at 0 degrees C), multiply by 29.92.
kgs/sq. cm, multiply by 1.0333.
kgs/sq. meter, multiply by 10332.
pounds/sq. in, multiply by 14.7.
tons/sq. ft, multiply by 1.058.

Mixture of gases that surround and are gravitationally attached to a planet.

For other uses, see Atmosphere (disambiguation).

"Atmospherics" redirects here. For the Bass Communion album, see Atmospherics (album).

View of Jupiter's active atmosphere, including the Great Red Spot.

An atmosphere (from Greek ἀτμός - atmos "vapor" and σφαῖρα - sphaira "sphere") is a layer of gases that may surround a material body of sufficient mass,^[1] by the gravity of the body, and are retained for a longer duration if gravity is high and the atmosphere's temperature is low. Some planets consist mainly of various gases, but only their outer layer is their atmosphere (see gas giants).

The term stellar atmosphere describes the outer region of a star, and typically includes the portion starting from the opaque photosphere outwards. Relatively low-temperature stars may form compound molecules in their outer atmosphere. Earth's atmosphere, which contains oxygen used by most organisms for respiration and carbon dioxide used by plants, algae and cyanobacteria for photosynthesis, also protects living organisms from genetic damage by solar ultraviolet radiation. Its current composition is the product of billions of years of biochemical modification of the paleoatmosphere by living organisms.

Contents 1 Pressure 2 Escape 3 Composition 4 Structure 4.1 Earth 4.2 Others 4.2.1 In our solar system 4.2.2 Outside our solar system 5 Circulation 6 Importance 7 See also 8 References 9 External links

Pressure

Main article: atmospheric pressure

Atmospheric pressure is the force per unit area that is applied perpendicularly to a surface by the surrounding gas. It is determined by a planet's gravitational force in combination with the total mass of a column of air above a location. Units of air pressure are based on the internationally-recognized standard atmosphere (atm), which is defined as 101,325 Pa (or 1,013,250 dynes per cm²).

The pressure of an atmospheric gas decreases with altitude due to the diminishing mass of gas above each location. The height at which the pressure from an atmosphere declines by a factor of e (an irrational number with a value of 2.71828..) is called the scale height and is denoted by H. For an atmosphere with a uniform temperature, the scale height is proportional to the temperature and inversely proportional to the mean molecular mass of dry air times the planet's gravitational acceleration. For such a model atmosphere, the pressure declines exponentially with increasing altitude. However, atmospheres are not uniform in temperature, so the exact determination of the atmospheric pressure at any particular altitude is more complex.

Escape

Main article: Atmospheric escape

Surface gravity, the force that holds down an atmosphere, differs significantly among the planets. For example, the large gravitational force of the giant planet Jupiter is able to retain light gases such as hydrogen and helium that escape from lower gravity objects. Second, the distance from the sun determines the energy available to heat atmospheric gas to the point where its molecules' thermal motion exceed the planet's escape velocity, the speed at which gas molecules overcome a planet's gravitational grasp. Thus, the distant and cold Titan, Triton, and Pluto are able to retain their atmospheres despite relatively low gravities. Interstellar planets, theoretically, may also retain thick atmospheres.

Since a gas at any particular temperature will have molecules moving at a wide range of velocities, there will almost always be some slow leakage of gas into space. Lighter molecules move faster than heavier ones with the same thermal kinetic energy, and so gases of low molecular weight are lost more rapidly than those of high molecular weight. It is thought that Venus and Mars may have both lost much of their water when, after being photodissociated into hydrogen and oxygen by solar ultraviolet, the hydrogen escaped. Earth's magnetic field helps to prevent this, as, normally, the solar wind would greatly enhance the escape of hydrogen. However, over the past 3 billion years the Earth may have lost gases through the magnetic polar regions due to auroral activity, including a net 2% of its atmospheric oxygen.^[2]

Other mechanisms that can cause atmosphere depletion are solar wind-induced sputtering, impact erosion, weathering, and sequestration — sometimes referred to as "freezing out" — into the regolith and polar caps.

Composition

Atmospheric gases scatter blue light more than other wavelengths, giving the Earth a blue halo when seen from space.

Initial atmospheric makeup is generally related to the chemistry and temperature of the local solar nebula during planetary formation and the subsequent escape of interior gases. These original atmospheres underwent much evolution over time, with the varying properties of each planet resulting in very different outcomes.

The atmospheres of the planets Venus and Mars are primarily composed of carbon dioxide, with small quantities of nitrogen, argon, oxygen and traces of other gases.

The atmospheric composition on Earth is largely governed by the by-products of the very life that it sustains. Earth's atmosphere contains roughly (by molar content/volume) 78.08% nitrogen, 20.95% oxygen, a variable amount (average around 0.247%, National Center for Atmospheric Research) water vapor, 0.93% argon, 0.038% carbon dioxide, and traces of hydrogen, helium, and other "noble" gases (and of volatile pollutants).

The low temperatures and higher gravity of the gas giants — Jupiter, Saturn, Uranus and Neptune — allows them to more readily retain gases with low molecular masses. These planets have hydrogen-helium atmospheres, with trace amounts of more complex compounds.

Two satellites of the outer planets possess non-negligible atmospheres: Titan, a moon of Saturn, and Triton, a moon of Neptune, which are mainly nitrogen. Pluto, in the nearer part of its orbit, has an atmosphere of nitrogen and methane similar to Triton's, but these gases are frozen when farther from the Sun.

Other bodies within the Solar System have extremely thin atmospheres not in equilibrium. These include the Moon (sodium gas), Mercury (sodium gas), Europa (oxygen), Io (sulfur), and Enceladus (water vapor).

The atmospheric composition of an extra-solar planet was first determined using the Hubble Space Telescope. Planet HD 209458b is a gas giant with a close orbit around a star in the constellation Pegasus. The atmosphere is heated to temperatures over 1,000 K, and is steadily escaping into space. Hydrogen, oxygen, carbon and sulfur have been detected in the planet's inflated atmosphere.^[3]

Structure

Earth

Main article: Earth's atmosphere

The Earth's atmosphere consists, from the ground up, of the troposphere (which includes the planetary boundary layer or peplosphere as lowest layer), stratosphere, mesosphere, thermosphere (which contains the ionosphere and exosphere) and also the magnetosphere. Each of the layers has a different lapse rate, defining the rate of change in temperature with height.

Three quarters of the atmosphere lies within the troposphere, and the depth of this layer varies between 17 km at the equator and 7 km at the poles. The ozone layer, which absorbs ultraviolet energy from the Sun, is located primarily in the stratosphere, at altitudes of 15 to 35 km. The Kármán line, located within the thermosphere at an altitude of 100 km, is commonly used to define the boundary between the Earth's atmosphere and outer space. However, the exosphere can extend from 500 up to 10,000 km above the surface, where it interacts with the planet's magnetosphere.

Others

Other astronomical bodies such as these listed have known atmospheres.

In our solar system

• Atmosphere of Mercury
• Atmosphere of Venus
• Atmosphere of Earth
  • Atmosphere of the Moon
• Atmosphere of Mars
• Atmosphere of Jupiter
  • Atmosphere of Io
  • Atmosphere of Callisto
  • Atmosphere of Europa
  • Atmosphere of Ganymede
• Atmosphere of Saturn
  • Atmosphere of Titan
  • Atmosphere of Enceladus
• Atmosphere of Uranus
  • Atmosphere of Titania
• Atmosphere of Neptune
  • Atmosphere of Triton
• Atmosphere of Pluto

Outside our solar system

• Atmosphere of HD 209458 b

Circulation

Main article: Atmospheric circulation

The circulation of the atmosphere occurs due to thermal differences when convection becomes a more efficient transporter of heat than thermal radiation. On planets where the primary heat source is solar radiation, excess heat in the tropics is transported to higher latitudes. When a planet generates a significant amount of heat internally, such as is the case for Jupiter, convection in the atmosphere can transport thermal energy from the higher temperature interior up to the surface.

Importance

From the perspective of the planetary geologist, the atmosphere is an evolutionary agent essential to the morphology of a planet. The wind transports dust and other particles which erodes the relief and leaves deposits (eolian processes). Frost and precipitations, which depend on the composition, also influence the relief. Climate changes can influence a planet's geological history. Conversely, studying surface of earth leads to an understanding of the atmosphere and climate of a planet - both its present state and its past.

For a meteorologist, the composition of the atmosphere determines the climate and its variations.

For a biologist, the composition is closely dependent on the appearance of the life and its evolution.

See also

Atmospheric sciences portal

• Atmometer (evaporimeter)
• Edge of space
• Ionosphere
• Sky
• Stellar atmosphere
• Table of Global Climate System Components

References

1. ^ Ontario Science Centre website
2. ^ Seki, K.; Elphic, R. C.; Hirahara, M.; Terasawa, T.; Mukai, T. (2001). "On Atmospheric Loss of Oxygen Ions from Earth Through Magnetospheric Processes". Science 291 (5510): 1939–1941. doi:10.1126/science.1058913. PMID 11239148. http://www.sciencemag.org/cgi/content/full/291/5510/1939. Retrieved 2007-03-07. 
3. ^ Weaver, D.; Villard, R. (2007-01-31). "Hubble Probes Layer-cake Structure of Alien World's Atmosphere". Hubble News Center. http://hubblesite.org/newscenter/newsdesk/archive/releases/1991/12/text/. Retrieved 2007-03-11. 

External links

• Properties of atmospheric strata - The flight environment of the atmosphere

v • d • e Atmospheres Major Sun · Venus · Earth · Mars · Jupiter · Saturn · Titan · Uranus · Neptune · Triton · Pluto · HD 209458 b Tenuous Mercury · The Moon · Io · Europa · Ganymede · Enceladus See also Stellar atmosphere  · Coma (cometary)  · Extraterrestrial atmospheres

This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)

Dansk (Danish)
n. - atmosfære, luftlag

idioms:

• one could cut the atmosphere with a knife    luften var så tyk, at man kunne skære i den
• with atmosphere    stemningsfuld

Nederlands (Dutch)
atmosfeer, sfeer, dampkring, (eenheid van) luchtdruk luchtlaag

Français (French)
n. - (lit, Phys) atmosphère, (fig) atmosphère, ambiance

idioms:

• one could cut the atmosphere with a knife    l'atmosphère était très tendue

Deutsch (German)
n. - Atmosphäre, Klima, Luft

idioms:

• one could cut the atmosphere with a knife    die Luft war zum Schneiden, die Atmosphäre war zum Zerreißen gespannt

Ελληνική (Greek)
n. - (μετεωρ.) ατμόσφαιρα, (μτφ.) κλίμα, (γενική) ατμόσφαιρα

idioms:

• one could cut the atmosphere with a knife    η ατμόσφαιρα ήταν άκρως τεταμένη
• with atmosphere    (για χώρο) με κατάλληλη ατμόσφαιρα

Italiano (Italian)
atmosfera

idioms:

• festive atmosphere    aria di festa
• layer of the atmosphere    strato dell'atmosfera
• with atmosphere    con ambiente
• work atmosphere    ambiente di lavoro
• working atmosphere    ambiente lavorativo

Português (Portuguese)
n. - atmosfera (f), ambiente (m)

idioms:

• festive atmosphere    atmosfera festiva
• layer of the atmosphere    camada (f) da atmosfera
• with atmosphere    com ambiente
• work atmosphere    ambiente de trabalho
• working atmosphere    ambiente de trabalho

Русский (Russian)
обстановка, атмосфера, воздух, озоновый слой

idioms:

• festive atmosphere    праздничная атмосфера
• layer of the atmosphere    атмосферный слой
• with atmosphere    с атмосферой (обыкн. позитивной)
• work atmosphere    рабочая обстановка
• working atmosphere    рабочая обстановка

Español (Spanish)
n. - ambiente, clima, atmósfera

idioms:

• one could cut the atmosphere with a knife    el ambiente se podía cortar con un cuchillo

Svenska (Swedish)
n. - atmosfär, stämning

中文（简体）(Chinese (Simplified))
大气, 气氛

idioms:

• one could cut the atmosphere with a knife    气氛很热闹
• with atmosphere    具有艺术气氛

中文（繁體）(Chinese (Traditional))
n. - 大氣, 氣氛

idioms:

• one could cut the atmosphere with a knife    氣氛很熱鬧
• with atmosphere    具有藝術氣氛

한국어 (Korean)
n. - 대기, 기압, 분위기, 맛

idioms:

• with atmosphere    ~의 분위기를 가진

日本語 (Japanese)
n. - 大気, 空気, 四囲の情況, 気圧, 全体的な感じ, 雰囲気, 一風変わった感じ

idioms:

• with atmosphere    ムードのある

العربيه (Arabic)
‏(الاسم) الجو, الغلاف الجوي‏

עברית (Hebrew)
n. - ‮אווירה, אטמוספירה, חלל האוויר, השפעה, יחידת לחץ השווה לממוצע הלחץ האטמוספרי בגובה פני-הים, אווירה נפשית, מצב-רוח, אווירה מתוחה, רגשות הנובעים מהתבוננות בתמונה או האזנה למוסיקה‬

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