Layers of the atmosphere - Revision history

Jmdonev: 1 revision imported

2018-06-25T14:30:24Z

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Jmdonev at 21:36, 4 June 2018

2018-06-04T21:36:30Z

← Older revision		Revision as of 21:36, 4 June 2018
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	~~[[Category:Done 2015-01-15 ]]~~
	[[category:371 topics]]		[[category:371 topics]]
	[[category:Lecture 1A a changing planet]]		[[category:Lecture 1A a changing planet]]
			[[Category:Done 2018-06-15]]
	<onlyinclude>Earth's [[atmosphere]] is a mixture of [[gas]]es that cover the planet's surface and are held there by [[gravity]].</onlyinclude> The atmosphere has different compositions, [[temperature]]s, and other properties at different heights. Notably, the gases in the lowest layers are under more [[pressure]] from the weight of the gases in the layers above them; for this reason, the atmosphere has a higher [[density]] at the planet's surface and becomes less and less dense, or "thinner," at higher altitudes.		<onlyinclude>Earth's [[atmosphere]] is a mixture of [[gas]]es that cover the planet's surface and are held there by [[gravity]].</onlyinclude> The atmosphere has different compositions, [[temperature]]s, and other properties at different heights. Notably, the gases in the lowest layers are under more [[pressure]] from the weight of the gases in the layers above them; for this reason, the atmosphere has a higher [[density]] at the planet's surface and becomes less and less dense, or "thinner," at higher altitudes.

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	\| [[File:Layers of the atmosphere exosphere.png\|200px]] \|\| Temperatures are only relevant for individual molecules, which vary widely from near [[absolute zero]] (-273[[Celsius\|°C]]) at night or in the shade to thousands of degrees in direct sunlight.\|\|Atmospheric temperature is essentially constant with altitude from this point upwards. Particles are still bound by Earth's gravity but no longer behave as a gas. Only the lightest gases are present: mainly [[Hydrogen]], but also [[Helium]], [[Carbon dioxide]], and atomic [[Oxygen]]. There is no clear upper boundary to the exosphere, which is a transition area between the atmosphere and space. Many satellites orbit at these heights.<ref name=NASA>NASA Jet Propulsion Laboratory. (2013). ''Atmosphere layers'' [Online]. Available: http://airs.jpl.nasa.gov/maps/satellite_feed/atmosphere_layers/ [Accessed 14 October 2013].</ref>		\| [[File:Layers of the atmosphere exosphere.png\|200px]] \|\| Temperatures are only relevant for individual molecules, which vary widely from near [[absolute zero]] (-273[[Celsius\|°C]]) at night or in the shade to thousands of degrees in direct sunlight.\|\|Atmospheric temperature is essentially constant with altitude from this point upwards. Particles are still bound by Earth's gravity but no longer behave as a gas. Only the lightest gases are present: mainly [[Hydrogen]], but also [[Helium]], [[Carbon dioxide]], and atomic [[Oxygen]]. There is no clear upper boundary to the exosphere, which is a transition area between the atmosphere and space. Many satellites orbit at these heights.<ref name=NASA>NASA Jet Propulsion Laboratory. (2013). ''Atmosphere layers'' [Online]. Available: http://airs.jpl.nasa.gov/maps/satellite_feed/atmosphere_layers/ [Accessed 14 October 2013].</ref>
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	\| [[File:Layers of the atmosphere thermosphere.png\|200px]] \|\| Temperatures increase with higher altitude, beginning around -120°C and reaching up to 2000°C at the upper limits.<ref name=nws>National Oceanic and Atmosphere Administration. (2013, July 22). ''Layers of the Atmosphere'' [Online]. Available: http://www.srh.noaa.gov/jetstream/atmos/layers.htm [Accessed 14 October 2013].</ref>\|\|The mixture of gas molecules is no longer consistent and molecules with higher mass sink to lower layers. Intense solar UV radiation causes ionization of the gas molecules and warms them to extreme temperatures. However, the air here is incredibly thin (near vacuum) and would not feel hot to the touch since it is nearly empty. Some satellites and the international space station are located at these altitudes, and solar winds cause ~~aurorae~~ near the north and south poles.<ref name=NASA/> The upper boundary is called the thermopause or exobase.		\| [[File:Layers of the atmosphere thermosphere.png\|200px]] \|\| Temperatures increase with higher altitude, beginning around -120°C and reaching up to 2000°C at the upper limits.<ref name=nws>National Oceanic and Atmosphere Administration. (2013, July 22). ''Layers of the Atmosphere'' [Online]. Available: http://www.srh.noaa.gov/jetstream/atmos/layers.htm [Accessed 14 October 2013].</ref>\|\|The mixture of gas molecules is no longer consistent and molecules with higher mass sink to lower layers. Intense solar UV radiation causes ionization of the gas molecules and warms them to extreme temperatures. However, the air here is incredibly thin (near vacuum) and would not feel hot to the touch since it is nearly empty. Some satellites and the international space station are located at these altitudes, and solar winds cause ''Aurora'' near the north and south poles.<ref name=NASA/> The upper boundary is called the thermopause or exobase.
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	\| [[File:Layers of the atmosphere mesosphere.png\|200px]] \|\| Temperatures range from -15°C to -120°C, decreasing with higher altitude<ref name=nws/>\|\|The mesosphere is too high for aircraft and too low for spacecraft to maintain orbit. Most meteors burn up as they fall through this layer of the atmosphere.<ref name=NASA/><ref name=nws/> It's upper boundary, the mesopause, is the coldest place on Earth.<ref name=NASA/>		\| [[File:Layers of the atmosphere mesosphere.png\|200px]] \|\| Temperatures range from -15°C to -120°C, decreasing with higher altitude<ref name=nws/>\|\|The mesosphere is too high for aircraft and too low for spacecraft to maintain orbit. Most meteors burn up as they fall through this layer of the atmosphere.<ref name=NASA/><ref name=nws/> It's upper boundary, the mesopause, is the coldest place on Earth.<ref name=NASA/>
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			==For Further Reading==
			*[[Atmospheric oxygen]]
			*[[Atmospheric pressure]]
			*[[Greenhouse effect]]
			*[[Pollution]]
			*[[Climate change]]
			*Or explore a [[Special:Random\| random page]]

	==References==		==References==
	{{reflist}}		{{reflist}}
	[[Category:Uploaded]]		[[Category:Uploaded]]

J.williams: 1 revision imported

2015-08-26T21:31:15Z

1 revision imported

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J.williams at 16:54, 12 August 2015

2015-08-12T16:54:56Z

New page

[[Category:Done 2015-01-15 ]]
[[category:371 topics]]
[[category:Lecture 1A a changing planet]]
<onlyinclude>Earth's [[atmosphere]] is a mixture of [[gas]]es that cover the planet's surface and are held there by [[gravity]].</onlyinclude> The atmosphere has different compositions, [[temperature]]s, and other properties at different heights. Notably, the gases in the lowest layers are under more [[pressure]] from the weight of the gases in the layers above them; for this reason, the atmosphere has a higher [[density]] at the planet's surface and becomes less and less dense, or "thinner," at higher altitudes.

The chemical composition, temperatures, movement and densities of the atmosphere at different heights differ widely enough that we recognize five distinct layers.<ref name=nws/> Their names, altitudes and qualities are as follows:

{| class="wikitable"
|-
! '''Name and Image'''<ref>Kelvin Case [CC BY-SA 2.5 (http://creativecommons.org/licenses/by-sa/2.5)], via Wikimedia Commons, ''Atmosphere layers'' [Online]. Available: https://commons.wikimedia.org/wiki/File:Atmosphere_layers-en_af.png. Accessed 18 August 2013.</ref> !! '''Temperature''' !! '''Description'''
|-
| [[File:Layers of the atmosphere exosphere.png|200px]] || Temperatures are only relevant for individual molecules, which vary widely from near [[absolute zero]] (-273[[Celsius|°C]]) at night or in the shade to thousands of degrees in direct sunlight.||Atmospheric temperature is essentially constant with altitude from this point upwards. Particles are still bound by Earth's gravity but no longer behave as a gas. Only the lightest gases are present: mainly [[Hydrogen]], but also [[Helium]], [[Carbon dioxide]], and atomic [[Oxygen]]. There is no clear upper boundary to the exosphere, which is a transition area between the atmosphere and space. Many satellites orbit at these heights.<ref name=NASA>NASA Jet Propulsion Laboratory. (2013). ''Atmosphere layers'' [Online]. Available: http://airs.jpl.nasa.gov/maps/satellite_feed/atmosphere_layers/ [Accessed 14 October 2013].</ref>
|-
| [[File:Layers of the atmosphere thermosphere.png|200px]] || Temperatures increase with higher altitude, beginning around -120°C and reaching up to 2000°C at the upper limits.<ref name=nws>National Oceanic and Atmosphere Administration. (2013, July 22). ''Layers of the Atmosphere'' [Online]. Available: http://www.srh.noaa.gov/jetstream/atmos/layers.htm [Accessed 14 October 2013].</ref>||The mixture of gas molecules is no longer consistent and molecules with higher mass sink to lower layers. Intense solar UV radiation causes ionization of the gas molecules and warms them to extreme temperatures. However, the air here is incredibly thin (near vacuum) and would not feel hot to the touch since it is nearly empty. Some satellites and the international space station are located at these altitudes, and solar winds cause aurorae near the north and south poles.<ref name=NASA/> The upper boundary is called the thermopause or exobase.
|-
| [[File:Layers of the atmosphere mesosphere.png|200px]] || Temperatures range from -15°C to -120°C, decreasing with higher altitude<ref name=nws/>||The mesosphere is too high for aircraft and too low for spacecraft to maintain orbit. Most meteors burn up as they fall through this layer of the atmosphere.<ref name=NASA/><ref name=nws/> It's upper boundary, the mesopause, is the coldest place on Earth.<ref name=NASA/>
|-
| [[File:Layers of the atmosphere stratosphere.png|200px]] || Averages range from -51°C to -15°C, increasing with higher altitude||Calm and stable with very few clouds, ideal for commercial jet flight. The [[stratosphere]] contains the [[ozone layer]], which consists of a band of Ozone gas (O<sub>3</sub>). Ozone blocks and absorbs energy from incoming UVA and UVB radiation, which warms the stratospheric air.<ref name=NASA/> This layer makes up 19% of the atmosphere by mass but contains almost no water vapour.<ref name=nws/> The stratopause marks the upper boundary and is the altitude where temperature reaches a maximum before decreasing in the mesosphere.
|-
| [[File:Layers of the atmosphere troposphere.png|200px]] || Averages range from 17°C to -51°C, generally decreasing with higher altitude<ref name=nws/>||The [[troposphere]] is heated mainly by the Earth's surface, and rising warm air causes rapid vertical mixing of the gases. Most weather phenomena occur here,<ref name=nws/> and the troposphere contains 99% of the atmosphere's water vapour.<ref name=NASA/> Marking its upper boundary is the tropopause, an area where temperature reaches a minimum before increasing with altitude in the stratosphere. The gases in this layer represent 75% of the atmosphere by mass and are comprised mainly of [[Nitrogen]] (78%) and [[Oxygen]] (21%) (see [[atmospheric oxygen]]).<ref name=NASA/>
|-
|}

==References==
{{reflist}}
[[Category:Uploaded]]