大气物理学课件试题

TheOriginoftheAtmosphereAtmosphericPhysics

银燕yinyan@杨军jyang@授课日期和时间：

星期一3-4节

星期三(单)7-8节地点：文德N310TheOriginoftheAtmosphereCONTENTIntroductionandOverview(大气科学导论）TheEarthSystem(地球科学概论)AtmosphericThermodynamicsRadiativeTransferAtmosphericChemistry(4)CloudMicrophysics(5)AtmosphericDynamics(4)WeatherSystems(大气科学导论，4)TheAtmosphericBoundaryLayer

（4）ClimateDynamics（6-”大气环流”）TheOriginoftheAtmosphere课程要求：作业和报告：

作业：至少3次，课程论文：1篇课程考核性质：考试课考核方式：

闭卷考试总评成绩计算方式：平时成绩占20%课程论文占20%期中考试成绩占25%期末考试成绩占35%TheOriginoftheAtmosphere主要参考数目：Wallace,JohnM.，PeterVHobbs:AtmosphericScience–AnIntroductorySurvey,2ndEd,Elsevier2006.Wallace,J.M.&P.V.Hobbs著，何金海等译:大气科学，科学出版社，2008年。盛裴轩等：大气物理学,北京大学出版社,2008年.Salby,M.L.:FundamentalsofAtmosphericPhysics,AcademicPress,1996.Fleagle，R.G.&J.A.Businger:AnIntroductiontoAtmosphericPhysics,2nd.Ed.AcademicPress,1980.

TheOriginoftheAtmosphereCh.1ThePlanetaryandEarth’sAtmosphere1TheOriginandEvolutionoftheEarthanditsAtmosphere1.2TheMassandChemicalCompositionoftheAtmosphere1.3TheVerticalStructureoftheAtmosphereTheOriginandEvolutionoftheEarthanditsAtmosphereEarthwasformedabout4.5BillionyearsagoFormedthroughcondensationandaccretionofgasesandothermaterialinthecosmosEarlyEarthwashot-about100oCforthefirst0.5BY,andpossiblynoatmosphereinashorttimeafteritwasformedPresentmassofmodernatmospheregeneratedwithinthefirstquarter(first1.25BY)ofEarth'sevolution.CrabNebula

(蟹状星云).PalomarObservatory,/photo/FactorsAffectingtheAtmosphericCompositionGasespresentwhentheplanetisformedDistancefromthesun:planetsclosertothesunhavehighertemperatures.Lightercomponentsofhotplanets"boiledaway"intospace.Sizeoftheplanet:theatmosphereishelddownbygravity!Considerthemoon'slackofanatmosphere.Rocksandoceans:Elementsmaybereleasedasgasesduringvolcaniceruptionsordissolvedintheoceans.Thesolarsystem:Mercury,Venus,Earth,Mars,Jupiter,Saturn,Uranus,Neptune,Pluto.TheThreeAtmospheresofEarthFirstatmosphere:

ComposedofgasesfromthegeneratingnebulaprincipallyH2,HeSecondatmosphere:

Firstatmosphereminusgases'boiledaway'tospaceplusgasesemittedfromvolcanoesplusgasesarrivingfromcometsetc.Modernatmosphere:

ResultingfromtheeffectsoflifeandtheadditionofoxygenSettingtheCompositionofthe2ndAtmosphere-VolcanoesGaseswereexpelledfromtheinterior(sameastoday)

CO2(~10%)

CO

SO2H2S(afewpercent)Cl2N2(afewpercent)H2O(~85%)H2

NH3

CH4Nooxygen!Attheobservedrateofoccurrence,Earthwouldreceive0.0025mmofwaterperyearFourbillionyearsofsuchbombardmentwouldgiveenoughwatertofilltheoceanstotheirpresentvolume.CometHalley(from/photo-gallery.TakenbyW.Liller

SettingtheCompositionofthe2ndAtmosphere-waterfromicycomets

FractionalconcentrationsbyvolumeofthemajorgaseousconstituentsoftheEarth’satmosphereuptoanaltitudeof105km,withrespecttodryairDifferentstoriesofEarthandVenus...CurrentphysicalandchemicalpropertiesofEarthandVenusTheRunawayGreenhouseEffect

onVenusCarbondioxideistheprincipalgreenhousegasHencewhyVenusissohotThe(Possible)ReasonforVenus’s

InhospitableClimateProbablygoesbacktotheinitialformationoftheplanet…EarthwascoolerHydratedphases,suchastalc(云母，Mg3SiO10(OH)2)retainedwaterintheEarthFormationofoceansonEarthledtoabsorptionofCO2CO2couldnotbeabsorbedbywateronVenus,soremainedinairtocausearunawaygreenhouseeffect.

Computer-generatedviewofVenus(from/photo-gallery.TakenbyW.LillerWhataboutMars?ChillyMarsMarsistoocoldforadvancedlifeformsThelowtemperaturesresultfrom:Alackofwatervapourintheair(waterisagoodgreenhousegas,butit’salllockedupinice)Agenerallymuchthinneratmosphere(duetolowplanetarymass)It’salongwayfromtheSunInsummary...

Venusistoohottosustainlife Marsistoocold Earthisjustright...

Allofthismeans…TheCompositionofEarth’s

2ndAtmosphereCompositionsetbyvolcanicemissionsextra-terrestrialinputchemicalreactionsbalancewiththeoceansweatheringofrocksOxygen-probablymuchlessthan1%ProducedbyactionoflightonwatermoleculesSulphur-presentashydrogensulphideratherthansulphurdioxideCarbon-CO2200-1000timespresentuntilitdissolvedinoceanslotsofcarbonmonoxideNitrogen-asinpresentatmosphereOxygenandLife…

TowardstheModernAtmosphereThepossiblesourcesofatmosphericoxygen:AbsorptionofUV2H2O2H2+O2(debatable)PhotosynthesisbyabsorptionofvisibleradiationH2O+CO2{CH2O}+O2

{CH2O}isthebasicbuildingblockforthecarbonhydratemoleculesthatformthecellsinplantlife.Photosynthesisisthemainprocesstoproduceoxygenintheearth’satmosphere.ThreeStepsfromthe

2ndAtmospheretothe

ModernAtmosphereSTEP1:CreationoflifeSTEP2:Originofoxygen-producingbacteriaSTEP3:ColonizationoftheplanetbyplantsSTEP1:TheBuildingBlocksofLife…

TheOrganicSoupExperimentStanleyMiller(1953)synthesizedaminoacidsbysendingelectricalsparksthroughsealedvesselscontainingammonia,methane,hydrogen,andsteamAminoacidsarethebuildingblocksofproteinsOtherstudiessuggestthatsuchaprimordialsoupcouldnothaveledtolife.MoreinformationisavailablehereSubmarineHydrothermalVentshavebeenfoundintheextremelyhotsulphurouswatersaroundmid-oceanridgehydrothermalvents.AminoacidshavebeenfoundalsoDeepoceanlifeshieldedfromUVConditionsmaybeidealfororiginoflife.FindoutmorehereBlackSmokerhydrothermalventontheoceanfloor.Photofrom/monsters/sea7a6.htmlTheOzoneLayerAlayeratabout12-20kmaltitudeFormsbytheactionofhighenergyUVonoxygengasOzoneshieldsEarthfrombio-destroyingUVradiationAnatmospherecontaining1%oxygencanformareasonablyeffectiveozonelayer.Shieldingofbio-damagingultravioletradiationbyozoneinthecurrent-daystratosphereSTEP2:Cyanobacteria-Architectsofthe

ModernAtmosphereAquaticandphotosyntheticWater+carbondioxide<->Sugar+OxygenOldestknownfossils(3.8billionyears)EarliestproducersofoxygenCreatedtheoxygenneededbyrespiringlifeformsStromatolites（叠层石）arestillaroundtodayFindoutmorehereStromatolitiesatSharkBay.Courtesyofcyanosite:Cyano-氰基STEP3:PlantsandtheRiseofOxygenSinglecelledplantsappeared2.1BYagoCoincideswiththerapidriseinoxygenSubsequentdevelopmentofatmospheredrivenlargelybylifeTheestimatedriseinoxygeninEarth’satmosphereovertime,basedongeochemicalandfossilevidenceAfavorablepathforlifeevolution:Single-celledorganisms(4BYago,O2freeenvironment)O2(photosynthesis,2-3BY,aqueousenvironmentfarbelowthesurface)O3(upperatmosphere)ReducedUVPlantlifespreadupwardandaccessesmorevisibleradiationMoreabundantplantlifeMoreO2Lifeemergedontoland4MYagoTheoxygenandcarbonbudgets过去40万年间，二氧化碳在大气中的浓度约为180～280ppm,工业化（1750年）以来，大气中温室气体明显增加100012001400160018002000年280300320340360CO2浓度（ppmv）南极LawDome冰芯资料显示的近1000年大气CO2浓度19601970198019902000年310320330340350300CO2浓度（ppmv）360370仪器测量的大气CO2浓度变化夏威夷MaunaLoa观象台测量的大气CO2浓度2004年达到378ppm,2005年创造了新的最高纪录

，达到了381ppm；我国青海瓦里关站观测的CO2浓度也在逐年上升1990919293949596979899002001年345350355360365370375CO2浓度（ppmv）MaunaLoa瓦里关Verticalprofilesofpressure,densityandmeanfreepathVerticaltemperatureprofileVerticaltemperatureprofileTroposphere:

accountsfor>80%ofatmosphericmassandalmostallofthewatervapo