高等大气物理复习题第1版

【NO.1】(a)TroposphereThetropospherebeginsattheEarth'ssurfaceandextendsfrom6to20kmhigh.Asthedensityofthegasesinthislayerdecreasewithheight,theairbecomesthinner.Therefore,thetemperatureinthetropospherealsodecreaseswithheightinresponse.Asoneclimbshigher,thetemperaturedropsfromanaveragearound17°Cto-51°Catthetopofthetroposphere.Almostallweatheroccursinthisregion.Thetransitionboundarybetweenthetroposphereandthelayeraboveiscalledthetropopause.Togetherthetropopauseandthetroposphereareknownastheloweratmosphere.(b)StratosphereTheStratosphereextendsfromthetopofthetroposphereuptoaround50kmabovetheEarth'ssurface.Thislayerholds19percentoftheatmosphere'sgasesbutverylittlewatervapor.Inthisregionthetemperatureincreaseswithheight.HeatisproducedintheprocessoftheformationofOzoneandthisheatisresponsiblefortemperatureincreasesfromanaverage-51°Cattropopausetoamaximumofabout-15°Catthetopofthestratosphere.Thisincreaseintemperaturewithheightmeanswarmerairislocatedabovecoolerair.Thisprevents"convection"sincethereisnoupwardverticalmovementofthegasesandisthereasonforthe'anvil-shaped'topsofcumulonimbusclouds.Theseanvilsoccuratthetropopause.积雨云的“砧状”顶部。这些砧发生在对流层顶。[ˈænvɪl][ˈkju:mjuləuˈnimbəs]Thetransitionboundarywhichseparatesthestratospherefromthemesosphereiscalledthestratopause.(c)MesosphereThemesosphereextendsfromthetopofthestratospheretoabout90kmabovetheearth.Thegases,includingtheoxygenmolecules,continuetobecomethinnerandthinnerwithheight.Assuch,theeffectofthewarmingbyultravioletradiationalsobecomeslessandlessleadingtoadecreaseintemperaturewithheight.Onaverage,temperaturedecreasesfromabout-15°Ctoaslowas-120°Catthemesopause.[ˈmɔlikju:l]However,thegasesinthemesospherearestillthickenoughtoslowdownmeteorshurtlingintotheatmosphere,wheretheyburnup,leavingfierytrailsinthenightsky.Boththestratosphereandthemesosphereareconsideredthemiddleatmosphere.ˈmitiɚ流星[ˈhɜ:tl]vi.猛冲；猛烈碰撞Thetransitionboundarywhichseparatesthemesospherefromthethermosphereiscalledthemesopause.(d)Thermosphere（热成层）Abovethemesospherethethermosphereextendsuptonear600kmabovetheearth.Thislayerisknownastheupperatmosphere.Thegasesofthethermosphereareincreasinglythinnerthaninthemesosphere.Assuch,incominghighenergyultravioletandx-rayradiationfromthesun,absorbedbythemoleculesinthislayer,causesalargetemperatureincrease.Becauseofthisabsorption,thetemperatureincreaseswithheightandcanreachashighas2,000°Cnearthetopofthislayer.(e)Exosphere[ˈeksəsfiə]散逸层TheExosphereistheoutermostlayeroftheatmosphere.Itextendsfromthetopofthethermosphereto10,000kmabovetheearth.Inthislayer,atomsandmoleculesescapeintospaceandsatellitesorbittheearth.（卫星沿轨道绕地球运行）adiabatic[英][ˌædiəˈbætik]adj.绝热的，隔热的gradient[英][ˈgreɪdi:ənt]n.[物]梯度，陡度；（温度、气压等）变化率，梯度变化曲线；【NO.2】p133staticbalance::Environment-density,constantDryadiabatic:q=0【NO.3】p134~135(1)位温-将气块从现有气压和温度绝热压缩或膨胀到标准气压（1000hPa）所具有的温度。位温公式可由热力学第一定律在绝热条件下导出。(2)physicalsignificance:everyairparcelhasauniquevalueofpotentialtemperature,andthisvalueisconservedfordryadiabaticmotion.Becausesynopticscalemotionsareapproximatelyadiabaticoutsideregionsofactiveprecipitation,θisaquasi-conservedquantityforsuchmotions.准守恒量ˈkwɑzi【NO.4】Staticsequation:Integralequation:【NO.5】Howtocomprehendthattheatmosphereisaphysicalsystem?？？？？？、Theatmosphereisaphysicalsystem。TheEarth’satmosphereisanaturallaboratory,inwhichawidevarietyofphysicalprocessestakesplace.（大气是一个物理系统。地球大气是一个自然实验室，其中有许多复杂多样的物理过程发生。）①Theatmosphereconsistsofamixtureofidealgases:althoughmolecularnitrogenandmolecularoxygenpredominatebyvolume,theminorconstituentscarbondioxide,watervapourandozoneplaycrucialroles.（大气由理想气体混合而成：虽然分子氮和分子氧占主要体积，但占主导地位的次要成分的二氧化碳，水蒸汽和臭氧发挥着关键作用。）②Theatmosphereiscontinuallybombardedbysolarphotonsatinfra-red,visibleandultra-violetwavelengths.（大气被太阳光子不断通过红外线、可见光及紫外线电磁波轰炸。）③Theatmosphereisgenerallyclosetohydrostaticbalanceinthevertical,exceptonsmallscales;thatis,theweightofeachhorizontalslabofatmosphereissupportedbythedifferenceinpressurebetweenitsloweranduppersurfaces.（除了小尺度，大气在垂直方向上是接近静力平衡的，也就是说大气的每一个水平面厚度的重量是由其上下平面的压力差的不同决定的。）Givenadensitystratificationofthiskind,asmallportionofairthatisdisplacedupwardsfromitsequilibriumpositionwillbenegativelybuoyantcomparedwithitssurroundingsandhencewillfallbacktowardsequilibrium,undergravity;similarlyadownward-displacedportionwillrisebacktowardsitsequilibriumposition.（鉴于这种密度分层，小部分空气从它的平衡位置向上运动，与环境相比将会产生负浮力，因此在重力作用下会返回并趋向于平衡，同样下沉的部分会上升回到它的平衡位置。）④Thermodynamicprinciplesareessentialfordescribingmanyatmosphericprocesses.Inatmosphericphysicsweusetheusualmacroscopicdefinitionsofthetemperatureandpressureofagas.（描述许多大气过程的热力学原理是必不可少的。在大气物理学中我们通常使用某种气体的温度和压力的宏观定义。）⑤Animportantfeatureofthebuoyancyrestoringeffectinastablystratifiedatmosphereisthatitcansupportfluid-dynamicalwaves,knownasgravitywaves,inwhichthefluidpressure,density,temperatureandvelocityfluctuatetogether.（在一个稳定分层大气中，恢复浮力效果的一个重要特征是能支持被称为重力波的流体动力学波，其中流体的压力、密度、温度和速度一起波动。）【NO.6】HoltonHadley,inseekingacauseforthetradewindcirculation,realizedthatthiscirculationmustbeaformofthermalconvectiondrivenbythedifferenceinsolarheatingbetweenequatorialandpolarregions.Hevisualizedthegeneralcirculationasconsistingofazonallysymmetricoverturninginwhichtheheatedequatorialairrisesandflowspolewardwhereitcools,sinks,andflowsequatorwardagain.Atthesametime,theCoriolisforcedeflectsthepolewardmovingairattheupperlevelstotheeast,andtheequatorwardmovingairnearthesurfacetothewest.Thelatteris,ofcourse,consistentwiththeobservedsurfacewindsinthetradewindzone,whicharenortheasterlyintheNorthernHemisphereandsoutheasterlyintheSouthernHemisphere.ThistypeofcirculationisnowcalledaHadleycirculationorHadleycell.Evidencefromanumberofstudiesindicatesthatforconditionsexistingintheearth’satmosphereasymmetrichemispheric-wideHadleycirculationwouldbebaroclinicallyunstable.Ifsuchacirculationweretobecomeestablishedbysomemechanism,itwouldquicklybreakdownoutsidethetropicsasbarocliniceddiesdevelopedandmodifiedthezonal-meancirculationthroughtheirheatandmomentumfluxes.heresultantobservedclimatologyoftheEulerianmeanmeridionalcirculationisshowninFig.10.7.ItconsistsprimarilyoftropicalHadleycellsdrivenbydiabaticheatingandeddy-drivenmidlatitudeFerrelcells.Therearealsominorthermallydirectcellsatpolarlatitudes.Themeridionalcirculationinthewinterismuchstrongerthanthatinthesummer,especiallyintheNorthernHemisphere.Thisreflectstheseasonalvariationbothinthediabaticandintheeddyfluxforcingtermsin(10.15).Answer:(a)ThemodelofHadleycirculationisdescribedasthatthesolarradiationheatingtheequatorialregions,thereforetheairflowriseupowingtoheatingintheequatorialregions.However,thehighlatitudesbecauseofcoolingprevalentdowndraft.Justlikethistheseniorairflowfromequatorialtopolarregion,thelowerairflowfrompolartoequatorialregion.TheHadleycirculationisaone-circlecirculation.Coriolisforce[英][ˌkɔ:riˈəulisfɔ:s](b)Inobservations,inthenorthernhemispheresomewesterflyflowblowingfromsouthinsteadofnorth.Andbecauseofcoriolisforcetheairflowblowingfromequatortopolarturnedintosouthwindinthesub-tropicalregions.Later,afterstudy,W.Ferrelproposedthemodelofthree-cellcirculation.Amongtheequatorandsub-tropicalregionsisaHadleycirculation(directcirculation),betweensub-tropicalregionsandpolarregionsisaHadleyanti-circulation(Ferrelcirculation),abovethepolarregionsisaHadlycirculationaswell.【NO.7】TheEkmanspiralisanequiangularspiralhavingthegeostrophicwindasitslimitpoint.ThisspiralEkman螺线是一种以地转风为参考的等角螺线。此螺线经过0点。在地转风之下，风穿越等linepassthroughthezeropoint.Belowthegeostrophicwindlevelthewindblowsacrosstheisobarstowardlowpressure,atananglethatisamaximumatthesurfaceanddoesnotexceed压线，从高压吹响低压，在地面螺线和地转风夹角最大，但不超过45°45°.thefirstcase:第一种情况Inverylowlayer,frictionforceisgreaterthanpressuregradientforce.FP+FC=FR在较低层大气，摩擦力大于气压梯度力。。。。。。。thesecondcase:第二种情况Inalittlehigherlayer,thefrictioncan'tbeignored,butpressuregradientforceisgreaterthan在高一点的大气中，虽然摩擦力不能被忽略，但此时的气压梯度力已经大于摩擦力了friction.TheresultantoffrictionandCoriolisforceispressuregradientforce.气压梯度力，摩擦力，地转偏向力三力平衡。thethirdcase:第三中情况Thefrictioncanbeignored.Coriolisforceequalspressuregradientforce.无视摩擦力，地转偏向力和气压梯度力平衡。【NO.8】(a)It’sameansofusingdetectiondeviceswhicharenotplacedinthemeasuringobjecttomeasurechangesoftheatmosphericelements.Accordingtothecharacteristicchangesinthespreadprocessofthesound,light,electricity,andothersignalsintheatmosphere,Itcanderivethechangesoftheatmosphericelementsintimeandspace.遥感探测：探测元件不置放于测量物体上，测量大气要素的变化,它根据大气中声、光、电等信号传播过程中性质的变化，反演出大气要素的时空变化(b)themostimportantcharacteristicsofRemotesensingiswidecoverage,high-frequency,informative,highsensitivityandaccuracy.遥感最主要的特点就是覆盖范围宽、频率快、信息量大、灵敏度和精度都非常高【NO.9】（此题还不完整，请同学们自己发挥）ThisistheHorizontalN-Sequation,whenfrictionforce,coriolisforce,gravityandhavebeenneglected,theequationbecomesthat【NO.10】Climateisthenormalorlong-termaveragestateoftheatmosphericenvironment(asdeterminedinspansofabout50years).Theatmosphereprotectsearth'slifeformsfromharmfulradiationandcosmicdebris.Theozonelayeralsoprotectstheearthfromthesun'sharmfulultravioletrays.VariableComponentsoftheAtmosphere:WaterVapour,LowLevelOzone,Aerosols（气溶胶）.Compositionalchangesintheearth'satmospheregeneratethreeprincipalclimaticeffects:THEGREENHOUSEEFFECT:Certaingases,calledgreenhousegases(primarilycarbondioxideandwatervapor;butalsomethane,N2O,andCFCs),allowshortwavelengthradiationfromthesun(UVandvisiblelight)topenetratethroughtheloweratmospheretotheearth'ssurface.Thesesamegases,however,absorblongwavelengthradiation(infrared),whichistheenergytheearthreradiatesbackintospace.Watervaporiskeytocloudformation.THEOZONEEFFECT:Intensesunlightinthestratosphere(above12km)producesbluishcoloredozone(O3)bynaturallybreakingdownnormaloxygenmolecules(O2)intotwohighlyreactiveoxygenatoms(O).Eachoxygenatomthenquicklybondswithanoxygenmoleculetoformozone.OzoneabsorbsUVradiation,andintheprocessozoneischangedbackintoanoxygenmoleculeandanoxygenatom.Abalanceexistsinozonedestructionandproduction,sothatanequilibriumconcentrationexistsinthestratosphere.Thisequilibriumhasprobablyexistedthroughoutmuchofgeologictime.Recently,however,anozoneholehasbeendetectedinthestratosphereoverAntarctica,presumablyduetotheatmosphericbuildupofozone-destroyingCFCsbyhumans.Ozonedepletionhasresultedinagreaterpenetrationofultravioletradiationontheearth'ssurface,whichisharmfultolifeonearthbecauseitdamagescellularDNA.Theozoneeffectdoesnotappeartohaveadirectinfluenceonglobaltemperatures.THEAEROSOLSEFFECT:Suspendedparticles,suchasdustandash,canblockouttheearth'ssunlight,thusreducingsolarradiationandloweringmeanglobaltemperatures.Theaerosolseffectoftengeneratesexceptionallyredsunsetsduetothescatteringofredwavelengthsbysubmicron-sizeparticlesinthestratosphereanduppertroposphere.【NO.11】p70普朗克定律：=(1)普朗克定律导出斯蒂芬—玻尔兹曼定律(少一个负号？)（2）普朗克定律导出维恩定律【NO.12】Whatisthedifferencebetweenwarmandcoldcloudprocess?云是由水蒸气组成的。习惯上。根据它的温度可分为暖云和冷云两种。

暖云里只有小水珠，温度在0℃以上。在上升气流的顶托下，这些水珠不会掉下来，而是漂浮在空中形成云层。如果在暖云中喷撒干冰，它的温度就会骤降，使水气达到饱和程度，水珠不断增大变成了雨滴下来，便形成了人工降雨。（丙）

冷云的气温可在0℃以下，里面充满着闪亮的冰晶和水珠，但由于它们又小又轻，在上升气流顶托下也不会掉下来。如果在冷云中播撒干冰，就会使它变得更冷，冰晶越积越多，越来越大。空气托不住它，就会往下掉。Warmcloudprocess:•amoistureairparcelrises,coolsatdryadiabaticlapserate(～1℃/100m)untilitreachesthedewpoint,atwhichpointcondensationoccurs.Afterthat,anyfurtherrisecausescoolingatthemoistadiabaticlapserate(0.5-0.9℃/100m),becauseofthereleasedlatentheat.•supersaturation:relativehumidity>100%•condensationnucleiareneededtoincreasecondensationmostefficientparticles:Aitkennuclei(0.01-0.1microm)typicalsource:dustfromland,seaspray(hygroscopic!)5million/lairoverland,1million/lairovertheocean•condensationonlycreatesdroplets<100micromradius,whileraindropsareoftheorderof1mm•cloudsarecontinuouslyforminganddissipating,someliveonly5to15minutes•dropletsmergeduetodirectimpactandcollisioninthewakeoffallingdrops.Coldcloudprocess:•saturationvaporpressureislowerovericethanwater=>icecrystalsgrowinfavorofliquiddroplets•icecrystalsareveryefficientcondensationnuclei•mostefficientinmidlatitudes(temperatureslowenough,butenoughinstabilityintheatmosphere)【NO.13】Pleasedrawtheillustrationsofahighpressuresystemfromtopandsideviewrespectively,andexplainwhythereisfairweatherunderhighpressure.（略）学过气象的肯定都会。【NO.14】(a)1)Thegroundheats/coolsupmoreandquickerthantheoceanbecausetheheatcapacityofsoilismuchlowerthanthewater.Duringdaytime,theheatedairoverlandbecomeslessdense（密）andrisesupwards.Thisalsoleadstoaformationoflowpressureoverland.Overtheocean,windblowstowardlandtomakeuptheverticalmotionoverland.Airalsosinksoveroceantomakeupthewindthatisblowingtowardsland.Aloft（在高空）,divergenceexistsoverland,andthewindblowsbacktowardtheocean.Whileduringnight