气象专业英语2教学文案

气象专业英语2Interface交界面，接口Interactioninternetinterannual(年际的）Numerical数值的Model模式Baroclinic斜压的barotropic正压的Cyclone气旋anticyclone反气旋cyclogenesis——气旋生成Depression低压isobaric等压的isothermal等温的Iso+..等。。Synoptic天气的PrincipleofSynopticMeteorology

天气学原理Convergence辐合divergence辐散Apex顶点，峰尖peak峰Zone区域regionCirrus卷云jet急流Lowleveljet低空急流Geostrophic地转的Convection对流convective对流的Greenhouse温室效应albedo反照率Evaporate蒸发v.Evaporation蒸发n.Occlusion锢囚squall飑Oceanic海洋的lee背风面Cyclogenesis气旋生成

Trough槽ridge脊Ana-front上滑锋kata-front下滑锋Slope坡度order量级Multi-layered多层的Multi-cell多单体的Cirrostratus卷层云altostratus高层云Nimbostratus雨层云stratocumulus层积云Drizzle毛毛雨precipitation降水Rainfall降水量saturate使饱和Descend下降ascend上升Medium-level中层high-levelLow-level低层mid-tropospheric对流层中部的Airflow气流Large-scale大尺度的meso-scale中尺度的momentum动量Broad-scale大范围的Potential位势，潜在的，Potentialheat潜热geopotentialmeter位势米Rainband雨带rainbeltOrographic地形的topographicDown-wind在下风方向Cumulonimbus积雨云Downpour倾盆大雨thunder雷Duration持续时间occlude锢囚Trowal(troughofwarmairaloft)高空暖舌Aloft高的，上面的Poleward向极地的Phase相位，阶段，方面TibetPlateaumoderateP1:①Thefirstrealadvance

inourdetailedunderstandingofmid-latitudeweathervariationswasmadewiththediscoverthatmanyoftheday-to-daychangesareassociatedwiththeformationandmovementofboundaries,orfronts,betweendifferentairmasses.

②Observations

ofthetemperature,winddirections,humidityandotherphysicalphenomenaduringunsettledperiodsshowedthatdiscontinuitiesoftenpersistbetweenimpingingairmassesofdifferingcharacteristics.

③Theterm“front”,

forthesesurfacesofairmassconflict,wasalogicaloneproposedduringtheFirstWorldWarbyagroupofmeteorologistsworkinginNorway,andtheirideasarestillanintegralpartofmostweatheranalysisandforecastingparticularlyinmiddleandhighlatitudes.1.

FrontalwavesP2:①Itwasobservedthatthetypicalgeometryoftheairmassinterface,orfront,resemblesawaveform.②Similarwavepatternsare,infact,foundtooccurontheinterfacebetweenmanydifferentmedia,forexample,wavesonseasurface,ripplesonbeachsand,aeoliansanddunes,etc.③Unlikethesewaveforms,however,thefrontalwavesintheatmospherearecommonlyunstable:thatis,theysuddenlyoriginate,increaseinsize,andthengraduallydissipate.④Numericalmodelcalculationsshowthat,inmiddlelatitudeswavesinabaroclinicatmosphereareunstableiftheirwavelengthexceedsafewthousandkilometers.⑤Frontalwavecyclonesaretypically1500-3000kminwavelength.Similarwavepatternsare,infact,foundtooccurontheinterfacebetweenmanydifferentmedia,forexample,wavesonseasurface,ripplesonbeachsand,aeoliansanddunes,etc.Itwasobservedthatthetypicalgeometryoftheair-massinterface,orfront,resemblesawaveform.1500-3000kminwavelength.Unlikethesewaveforms,however,thefrontalwavesintheatmospherearecommonlyunstable:thatis,theysuddenlyoriginate,increaseinsize,andthengraduallydissipate.⑥Theinitiallyattractiveanalogy

betweenatmosphericwavesystemsandwavesformedoninterfaceofothermediais,therefore,aninsufficient-basisonwhichtodevelopexplanationsoffrontalwaves.⑦Inparticular,thecirculationoftheuppertroposphereplaysakeyrole

inprovidingappropriateconditionsfortheirdevelopmentandgrowth,aswillbeshownbelow.2.

ThefrontalwavedepressionP3:

①Adepression(alsotermedaloworcyclone)isanareaofrelativelylowpressure,withamoreorlesscircularisobaricpattern.②Itcoversanarea100-3000kmindiameterandusuallyhasalife-spanof4-7days.③Systemswiththesecharacteristics,whichareprominentondailyweathermaps

arereferredto

assynopticscalefeatures.④Thedepression,inmid-latitudesatleast,isusuallyassociatedwithaconvergenceofcontrastingairmasses.⑤Theinterfacebetweentheseairmassesdevelopsintoawaveformwithitsapexlocatedatthecentreofthelow-pressurearea.⑥Thewaveenclosesamassofwarmairbetweenmodifiedcoldairinfrontandfreshcoldairintherear.⑦Theformationofthewavealsocreatesadistinctionbetweenthetwosectionsoftheoriginalairmassdiscontinuityfor,althougheachsectionstillmarkstheboundarybetweencoldandwarmair,theweathercharacteristicsfoundintheneighborhoodofeachsectionareverydifferent.⑧Thetwosectionsofthefrontalsurfacearedistinguishedbythenameswarmfrontfortheleadingedgeofthewaveandcoldfrontforthatofthecoldairtotherear.modifiedcoldairfreshcoldairwarmairP4:Thedepressionusuallyachievesitsmaximumintensity12-24hoursafterthebeginningofocclusion.FrontalcharacteristicsP5:①Theactivityofafrontintermsofweatherdependsupontheverticalmotionintheairmasses.②Iftheairinthewarmsectorisrisingrelativetothefrontalzone,thefrontsareusuallyveryactiveandaretermedana-fronts.③Whereassinkingofthewarmairrelativetothecoldairmassesgivesrisetolessinactivekata-fronts.1.ThewarmfrontP6:

①Thewarmfrontrepresentstheleadingedgeofthewarmsectorinthewave.②Thefrontalzoneherehasaverygentleslope,oftheorder1/2°-1°,sothatthecloudsystemsassociatedwiththeupperportionofthefrontheralditsapproachsome12hoursormorebeforethearrivalofthesurfacefront.③Theana-warmfront,withrisingwarmair,hasmulti-layeredcloudwhichsteadilythickensandlowerstowardsthesurfacepositionofthefront.④Thefirstcloudsarethin,wispycirrus,followedbysheetsofcirrusandcirrostratus,andaltostratus.高层云卷层云⑤Thesunisobscuredasthealtostratuslayerthickens,anddrizzleorrainbeginstofall.⑥Thecloudoftenextendsthroughmostofthetroposphereandwithcontinuousprecipitationoccurringisgenerallydesignatedasnimbostratus.⑦Patchesofstratusmayalsoforminthecoldairasrain

fallingthroughthisairundergoesevaporationandquicklysaturatesit.P7:①Thedescendingwarmairofthekata-warmfrontgreatlyrestrictsthedevelopmentofmedium-andhigh-levelclouds.②Thefrontalcloudismainlystratocumulus,withalimiteddepthasaresultofthesubsidenceinversionsinbothairmasses.③Precipitationisusuallylightrainordrizzleformedbycoalescencesincethefreezingleveltendstobeabovetheinversionlayer,particularlyinsummer.P8:①Inthepassageofthewarmfrontthewindveers,thetemperaturerisesandthefallofpressureischecked.②Therainbecomesintermittentorceasesinthewarmairandthethinstratocumuluscloudsheetmaybreakup.P9:①Forecastingtheextentofrainbeltsassociatedwiththewarmfrontiscomplicatedbythefactthatmostfrontsarenotana-orkata-frontsthroughouttheirlengthorevenatalllevelsinthetroposphere.②Forthisreason,radarisbeingusedincreasinglytodeterminebydirectmeansthepreciseextentofrainbeltsandtodetectdifferencesinrainfallintensity.P10:①Suchstudieshaveshownthatmostoftheproductionanddistributionofprecipitationiscontrolledbyabroadairflowafewhundredkilometresacrossandseveralkilometresdeep,whichflowsparalleltoandaheadofthesurfacecoldfront.P11:①Justaheadofthecoldfronttheflowoccursasalow-leveljetwithwindsupto25-30m/satabout1kmabovethesurface.②Theair,whichiswarmandmoist,risesoverthewarmfrontandturnssoutheastwardaheadofitasitmergeswiththemidtroposphericflow.③Thisflowhasbeentermeda“conveyorbelt”(forlarge-scaleheatandmomentumtransferinmid-latitudes).④Broad-scaleconvective(potential)instabilityisgeneratedbytheover-runningofthislow-levelflowbypotentiallycolder,drierairinthemiddletroposphere.⑤Instabilityisreleasedmainlyinsmall-scaleconvectioncellsthatareorganizedintoclusters,knownasmeso-scaleprecipitationareas(MPAs).⑥TheseMPAsarefurtherarrangedinbands,50-100kmwide.⑦Aheadofthewarmfront,thebandsarebroadlyparalleltotheairflowintherisingsectionoftheconveyorbelt,whereasinthewarmsectortheyparallelthecoldfrontandthelow-leveljet.⑧Insomecases,cellsandclustersarefurtherarrangedinbandswithinthewarmsectorandaheadofthewarmfront.⑨Precipitationfromwarmfrontrainbandsofteninvolves“seeding”byiceparticlesfallingfromtheuppercloudslayers.⑩Ithasbeenestimatedthat20%-35%oftheprecipitationoriginatesinthe“seeder”zoneandtheremainderinthelowerclouds.⑾Someofthecellsandclustersareundoubtedlysetupthroughorographiceffectsandtheseinfluencesmayextendwelldown-windwhentheatmosphereisunstable.2.ThecoldfrontP12:①Theweatherconditionsobservedatcoldfrontsareequallyvariable,dependinguponthestabilityofthewarmsectorairandtheverticalmotionrelativetothefrontalzone.②Theclassicalcold-frontmodelisoftheana-type,andthecloudisusuallycumulonimbus（积雨云）.③OvertheBritishIslesairinthewarmsectorisrarelyunstable,sothatnimbostratus（雨层云）occursmorefrequentlyatthecoldfront.④Withthekata-coldfrontthecloudisgenerallystratocumulus（层积云）andprecipitationislight.⑤Withana-coldfrontsthereareusuallybrief,heavydownpourssometimesaccompaniedbythunder.⑥Thesteepslopeofthecoldfront,roughly2°,meansthatthebadweatherisofshorterdurationthanatthewarmfront.⑦Withthepassageofthecoldfrontthewindveerssharply,pressurebeginstoriseandtemperaturefalls.⑧Theskymayclearveryabruptly,evenbeforethepassageofthesurfacecoldfrontinsomecases,althoughwithkata-coldfrontsthechangesarealtogethermoregradual.3.TheocclusionP13:

①Occlusionsareclassifiedaseithercoldorwarm,thedifferencedependingontherelativestatesofthecoldairmasseslyinginfrontandtotherearofthewarmsector.②Iftheairiscolderthantheairfollowingitthentheocclusioniswarm,butifthereverseisso,itistermedacoldocclusion.③TheairinadvanceofthedepressionismostlikelytobecoldestwhendepressionoccludeoverEuropeinwinterandverycoldofairisaffectingthecontinent.awarmocclusionacoldocclusionaneutralocclusionP14:①Thelineofthewarmairwedgealoftisassociatedwithazoneoflayeredcloudandoftenofprecipitation.②Henceitspositionisindicatedseparatelyonsomeweathermapsand