Materiálové složení
Theatmosphereontheearthhasconstantgascomponentssuchasnitrogen,oxygen,andargon,aswellasgascomponentswithrelativelyfixedcontentsuchascarbondioxideandnitrousoxide.Therearealsohighlyvariablegascomponentssuchaswatervapor,carbonmonoxide,sulfurdioxide,andozone.Solidandliquidaerosolparticlessuchasdust,smokeparticles,saltparticles,waterdroplets,icecrystals,pollen,spores,bacteria,etc.areoftensuspended.
Gascomposition
Dusík (78,084 %), kyslík (20,946 %), argon (0,934 %), vodní pára (0,25 %), oxid uhličitý (0,032 %), neon (0,0018 %), helium (0,00052 %), metan (0,0002 %), krypton (0,0001 %), vodík (0,00005 %), xenon (0,000008 %), ozon (0,000001 %), ostatní (0,001421 %).
Mostofthemareneutralmoleculesbelow60km;from60kmupwards,theybegintoionizeundertheactionofsolarradiationduringtheday,andmostofthemareionizedabove90km.Intheupperatmosphere,somecomponentsarestilldecomposedintoatomicstates.
Vývoj kompozice
Theearth’satmosphereisconstantlyevolvingwiththedevelopmentoftheearth,andittookalongtimetoformtoday’ssituation.
Accordingtoinference,themainelementsthatmakeuptheearth’sprimitiveatmospherearehydrogen,helium,carbon,nitrogen,oxygenandsoon.Undertheactionofgravity,theheavierelements(carbon,nitrogen,oxygen,etc.)areeasiertobepreservedbytheearth,andthelighterelementsareeasiertoescape.Atthesametime,elementswithrelativelyactivechemicalpropertiesarelikelytoformcompoundsandbepreserved(suchashydrogen,carbon,nitrogen,oxygen,etc.).Theinertandlightheliumisnoteasilypreservedbytheearth'satmosphere.Intheprocessofcompoundformation,firstly,hydrogenandcarboncombinetoformmethane,andmethanereactswithoxygentoformwaterandcarbondioxide.Inaddition,nitrogencombineswithhydrogenationtoproduceammonia,whichoxidizestoproducewaterandnitrogen.Therefore,theinitialcomponentsoftheearth’satmospherearemainlymethane,watervapor,carbondioxideandnitrogen.
About300millionyearsago,thecompositionoftheearth’satmospherechangeddramatically,namelythereductionofcarbondioxideandtheincreaseofoxygen.Theincreaseofoxygenintheatmospherehasacounterproductiveeffectonlifeactivities,whichpromotesthefurtherdevelopmentoforganisms.Respirationisalsotakingplaceinthelifeactivitiesoforganisms,thatis,absorbingoxygenandexpellingcarbondioxide.Duetothelargenumberofgreenplants,ontheonehand,thereductionofcarbondioxideintheatmosphereandtheincreaseofoxygenarecaused,ontheotherhand,anewcycleofoxygenandcarbondioxideintheatmosphereisgraduallyrealized.Thisprocesshasalong-termdevelopmentbetweentheatmosphereandorganisms.Intheprocess,mutualinfluenceandmutualrestraintareestablished,andthedynamicequilibriumstateofoxygenandcarbondioxideisestablished,andthecontentofoxygenandcarbondioxideintheatmospherealsostabilizes.
Thereductionofozoneinthemiddleatmospherecontinuestodevelop,andcontinuesfromthelastcenturytothiscentury.
Emise skleníkových plynů (oxid uhličitý, metan, freon atd.) způsobené lidskou činností skutečně způsobují vážné obavy z globálního oteplování.
Dopady lidských činností
Ničení pralesů
Forestsarethemainconsumersofcarbondioxideingreenplants,aswellasThemakerofoxygen.Itisestimatedthatduringthegrowingseason,thegeneralbroad-leavedforestcanabsorbaboutonetonofcarbondioxideperhectareperdayandproduce730kgofoxygen.Ifthetotalcarboncontentoftheworld’sforestsisestimatedtobe450tons,iftheaverageannualtreeis30years,thenabout55billiontonsofcarbondioxideareconsumedeveryyear.Itcanbeinferredthatsincetheprimevalforestisreducedby1/2,theannualcarbondioxideconsumedbytheforestisreducedbyapproximately55billiontons.Asaresult,thecarbondioxidecontentintheatmosphereincreases.
Masivní spalování uhlí, ropy a jiných paliv
Thefossilfuelsformedinthepasthundredsofmillionsofyearshavebeenexploitedinlargequantities,andtheconsumptionofoilisevenmoreintense.increase.Accordingtostatistics,theworld'scoalandoilproductionwas1.8billiontonsand500milliontonsrespectivelyin1950,andbothreached2.7billiontonsin1975,anincreaseof50%andnearlyfourtimesrespectively.Becausetheconsumptionofmaterialscannotberecoveredbycombustion,theburningofalargeamountoffuelisincreasingdaybyday,resultingintheconsumptionofoxygenintheatmosphereandtheincreaseofcarbondioxide,makingthenaturalcarbonandoxygencycleimbalance.Theincreaseincarbondioxideintheatmosphereandtheconsumptionofoxygenareaseriousprobleminthelongterm.
Rozvoj zemědělství
Therapiddevelopmentofagriculturalproductionhascausedcropphotosynthesistoproceedonanunprecedentedscale.Circulationplayedapositiveroleinpromoting.Thishasmadecertainadjustmentstotheimbalanceofthenaturalmaterialcirculationprocesscausedbythedestructionofalargenumberofvirginforests.Intheprocessofagriculturaldevelopment,theroleoflegumerhizobiaandtheincreaseofsyntheticnitrogenfertilizersaresignificant,whichalsopromotesthenitrogencycle.
Jiné dopady
Leadandhigh-octanedecompositionproductsemittedbyjetaircrafthaveanimpactontheozonelayer.Ifnotcontrolled,itwilldestroyTheozonelayer,organismsonthesurfacewillbeexposedtoharmfulultravioletradiation.Inaddition,high-altitudeflightalsocausedanincreaseinhigh-altitudecirrusclouds.
Asfarasthesituationisconcerned,themoreprominentmanifestationoftheimpactofhumanactivitiesontheatmosphereistheincreaseincarbondioxide,dustandpollutants.Althoughhumanactivitiesalsohaveacertainimpactonthecycleofnitrogenandoxygeninnature,thecontentofnitrogenandoxygenintheatmosphereisabsolutelydominant.Relativelyspeaking,thisimpactisextremelysmall.Itcanbeconsideredthatithasbeenformedinnatureforalongtime.Thedynamicbalanceofnitrogenandoxygenhasnotbeenseverelydestroyed.
PlanetaSolární Systém
Osm planet sluneční soustavy lze velmi rozdělit do dvou kategorií: 4 vnitřní planety (Merkur, Venuše, Země, Mars) blízko Slunci jsou pevné planety. Jejich velikost a hmotnost jsou relativně malé. Vnější čtyři planety (Jupiter, Saturn, Uran, a jako planeta jsou planety v rovině Neptun)
Solidplanetsandgaseousplanetsinthesolarsystemhavecompletelydifferentatmosphericcompositions.Amongthesolidplanets,theatmosphereofMercuryisverythin,basicallynegligible.ThemainatmosphericcompositionofVenusandMarsisCO2,whilethemainatmosphericcompositionoftheEarthisnitrogen(N2)andoxygen(O2).Themainatmosphericcomponentsofthesurroundingfourgaseousplanetsarehydrogen(H2)andhelium(He).
Exoplanetatmosféra
Duetothelongdistance,theexistingastronomicalobservationtechnologycanprovideuswithinformationaboutthechemicalcomposition,thermalstructureandatmosphericcirculationcharacteristicsoftheexoplanetatmosphere.Verylimited.However,itcanbeinferredthattheatmosphericchemicalcompositionofexoplanetscanberoughlydividedintothefollowingtypes:
ExoplanetswhosemassismuchlessthanthemassoftheEartharesolidplanets,andtheyprobablydonothaveanatmosphere.Thisisbecausethegravitationalforceofaplanetwithasmallermassisalsosmaller,andthethermalmotionspeedofthegasmoleculesinitsatmospherecaneasilyreachtheescapespeedoftheplanet,causingthegasmoleculestoescapeintospace.Moreover,thesolarwindeasilyerodestheatmosphereandblowsgasmoleculesintospace.
However,ifexoplanetswithsmallermassesarefartherawayfromthestar,thetemperatureoftheatmosphereislower,thethermalspeedofgasmoleculesisslow,andgasmoleculesarenoteasytoescape,theseasteroidsmaystillhaveanatmosphere.
ExoplanetswhosemassismuchgreaterthanthemassoftheEarth,especiallytheJupiter-likeplanetswhosemassismorethan30timesthemassoftheEarth,shouldhavesimilaratmosphericcomponentstothoseofthesolarsystemJupiterandSaturn.HThemassesof2andHeaccountformorethan99%ofthetotalmassoftheatmosphere(theproportionsofH2andHeareabout89%and10%),thesetwocomponentsaretheBigBangThemaincomponentoftheprimitivenebulaleftbehindisalsothemostabundantmatterintheuniverse.
Exoplanetswithamassbetween10and30timesthemassoftheEarthshouldalsohaveatmosphericcompositionbasedonH2andHe,similartothesolarsystem'sUranusandNeptune.ButintheatmospheresofUranusandNeptune,theproportionofH2islowerthanthatofJupiterandSaturn,about80%,whiletheproportionofHeisrelativelyhigher,about18%.Thecontentofmethaneandammoniaintheatmosphereoficyplanetsishigherthanthatofgiantgaseousplanets.