Stratosphere: Difference between revisions

The '''stratosphere''' ({{IPAc-en|ˈ|s|t|r|æ|t|ə|ˌ|s|f|ɪər|,_|-|t|oʊ|-}}) is the second-lowest [[atmospheric stratification|layer]] of the [[atmosphere of Earth]], located above the [[troposphere]] and below the [[mesosphere]].<ref>{{Citation |last=Jones |first=Daniel |author-link=Daniel Jones (phonetician) |title=English Pronouncing Dictionary |editor=Peter Roach |editor2=James Hartmann |editor3=Jane Setter |place=Cambridge |publisher=[[Cambridge University Press]] |orig-year=1917 |year=2003 |isbn=978-3-12-539683-8 }}</ref><ref>{{MerriamWebsterDictionary|Stratosphere}}</ref> The stratosphere is an atmospheric layer composed of [[Atmosphericstable and unstable stratification|stratified]] [[temperature]] layerszones, with the warmwarmer layers of [[air]] highlocated inhigher the(closer skyto [[outer space]]) and the coolcooler layers oflower air in the low sky, close(closer to the [[planetary surface]] of the Earth). The increase of temperature with [[altitude]] is a result of the absorption of the [[Sun]]'s [[ultraviolet]] (UV) radiation by the [[ozone layer]], where [[ozone]] is [[exothermic]]ally [[photodissociation|photolyze]]d into [[oxygen]] in [[ozone-oxygen cycle|a cyclical fashion]].<ref name=ucarOverview>{{cite web |title=The Stratosphere - overview |url=https://scied.ucar.edu/shortcontent/stratosphere-overview |website=scied.ucar.edu |publisher=University Corporation for Atmospheric Research |access-date=25 July 2018 |language=en}}</ref> This The[[inversion (meteorology)|temperature inversion]] is in contrast to the troposphere, where temperature decreases with altitude, and nearbetween the Earth'stroposphere surface,and wherestratosphere temperatureis decreasesthe with[[tropopause]] altitudeborder that demarcates the beginning of the temperature inversion.

Between the troposphere and stratosphere isNear the [[tropopauseequator]] border that demarcates the beginning of the [[Inversion (meteorology)|temperature inversion]]. Near the equator, the lower edge of the stratosphere is as high as {{convertcvt|20|km|sigfig=2|ft mi|abbr=on}}, at midlatitudesmid-latitudes around {{convertcvt|10|km|sigfig=2|ft mi|abbr=on}}, and at the [[geographical pole|poles]] about {{convertcvt|7|km|sigfig=2|ft mi|abbr=on}}.<ref name=ucarOverview/> Temperatures range from an average of {{convertcvt|-51|C|sigfig=2|F K|abbr=on}} near the tropopause to an average of {{convertcvt|-15|C|sigfig=2|F K|abbr=on}} near the mesosphere.<ref name="nwsJetStream">{{cite web |title=NWS JetStream - Layers of the Atmosphere |url=https://www.weather.gov/jetstream/layers |website=www.weather.gov |language=EN-US}}</ref> Stratospheric temperatures also vary within the stratosphere as the seasons[[season]]s change, reaching particularly low temperatures in the [[polar night]] (winter).<ref name="nasaOzoneWatch">{{cite web |title=Nasa Ozone Watch: Polar vortex facts |url=https://ozonewatch.gsfc.nasa.gov/facts/vortex_NH.html |website=ozonewatch.gsfc.nasa.gov |language=en-us}}</ref> Winds[[Wind]]s in the stratosphere can far exceed those in the troposphere, reaching near {{convertcvt|60|m/s|km/h mph|abbr=on}} in the Southern [[polar vortex]].<ref name="nasaOzoneWatch"/>

The mechanism describing the formation of the ozone layer was described by British mathematician and [[geophysicist]] [[Sydney Chapman (mathematician)|Sydney Chapman]] in 1930, and is known as the Chapman cycle or [[ozone–oxygen cycle]].<ref>{{Cite webbook |titlelast=CHAPTER 10.Jacob STRATOSPHERIC|first=Daniel J. OZONE|url=http://acmg.seas.harvard.edu/people/faculty/djj/book/bookchap10.html |title=Introduction to Atmospheric Chemistry |access-date=2020-10-201999 |websitepublisher=acmgPrinceton University Press |isbn=9781400841547 |chapter=CHAPTER 10.seas.harvard.edu STRATOSPHERIC OZONE |archiveaccess-date=20192020-0910-3020 |archive-url=https://web.archive.org/web/20190930034719/http://acmg.seas.harvard.edu/people/faculty/djj/book/bookchap10.html |archive-date=2019-09-30 |url-status=dead |via=acmg.seas.harvard.edu}}</ref> Molecular oxygen absorbs high energy sunlight in the [[UV-C]] region, at wavelengths shorter than about 240&nbsp;nm. Radicals produced from the homolytically split oxygen molecules combine with molecular oxygen to form ozone. Ozone in turn is [[photodissociation|photolysed]] much more rapidly than molecular oxygen as it has a stronger absorption that occurs at longer wavelengths, where the solar emission is more intense. Ozone (O₃) photolysis produces O and O₂. The oxygen atom product combines with atmospheric molecular oxygen to reform O₃, releasing heat. The rapid photolysis and reformation of ozone heat the stratosphere, resulting in a temperature inversion. This increase of temperature with altitude is characteristic of the stratosphere; its resistance to vertical mixing means that it is stratified. Within the stratosphere temperatures increase with altitude ''(see [[temperature inversion]])''; the top of the stratosphere has a temperature of about 270 [[Kelvin|K]] (−3[[°C]] or 26.6[[°F]]).<ref>{{Cite book |last=Seinfeld, |first=J. H., and S. N.(2006), |title=Atmospheric Chemistrychemistry and Physicsphysics: Fromfrom Airair Pollutionpollution to Climateclimate Changechange 2nd|last2=Pandis ed,|first2=S. N. |date=2006 |publisher=Wiley, New|isbn=978-0-471-72018-8 Jersey|edition=2nd |location=Hoboken, NJ}}</ref>{{pn|date=June 2024}}

The [[Concorde]] aircraft cruised at [[Mach number|Mach 2]] at about {{convert|60000|ft|km|0|abbr=on}}, and the [[SR-71]] cruised at Mach 3 at {{convert|85000|ft|km|0|abbr=on}}, all within the stratosphere.