江淮梅雨環(huán)流特征及其前期結(jié)構(gòu)演變與東亞副熱帶季風(fēng)關(guān)系的研究.pdf

1、南京信息工程大學(xué)碩士學(xué)位論文江淮梅雨環(huán)流特征及其前期結(jié)構(gòu)演變與東亞副熱帶季風(fēng)關(guān)系的研究姓名：劉丹妮申請學(xué)位級別：碩士專業(yè)：氣象學(xué)指導(dǎo)教師：何金海20100401全文摘要AbstractBasedondatasetsseparatelyprovidedbyClimateCenterofChinaMeteorologicalAdministrationandJiangsuMeteorologicalBureau，acomparisonism

2、adetochoosetheyearswithuniformbeginningdateofMeiyuAcomposedanalysisisappliedtodetectthetypicalcirculationpatternduringMeiyuaswellasitsevolutionsTheresultssuggestacluetotheassociationbetweentypicalstructureandEastAsiaSubt

3、ropicalMonsoon(EASM)ThecirculationdevelopmentsinrelationtoEASMestablishmentarediscussedfurtherInthefinalpart，precursorysignalsconcernwithrainfallamountduringMeiyuispresentedThemainconclusionsareasfollows：(1)Thewesternext

4、ensionofthelow—leveljet，accompaniedwiththenorthwardofhigh—levelwestlyjetishelpfultothedevelopmentoftheverticalmotionduringMeiyuBesides，thecirculationOVerIndianPeninsulaJiangHuaibasinwitheasterncoastlineofChinaandthemiddl

5、eNorthPacificaresignificantlychanged，whichissimilarto“IEA”telecormectionpatternThelowlevelconvergencecenteralwayscoincideswithrainbeltbeforeandafterbeginningofMeiyu，inwhichthemcridionalconvergenceplaysadominantroleThe‘‘d

6、oublefeet’’vorticityfield‘‘saddlelike’’temperature—humidityfieldand目seintensivebeltcharacterizedtypicalstructureofMeiyu，whichisformedinthelateMarchtoearlyApril，correspondingwiththeestablishmentofEASMandtheoccurrenceofpre

7、cipitation(2)Theadjustmentonthecirculationfieldcausedbyzonalthermalcontrastreversioncanbeconcludedasbelow：ThecoldhighOVereasternChinaeastwardsandweakenedwhilethesubtropicalhi曲westwardandenhancedinlowlayerleadingtotransfo

8、rmationof“westhigh，eastlow”to“westloweasthi曲”inpotentialheightfield；Inthemiddletroposphere，long—waveadjustmenttakesplaceinmiddlehighlatitude，OkhotsktroughtumstoridgewhileBeringridgetunistotroughThesubtropicalwesterlyjetd

9、eclineandnorthwardstothesummerstageIntheuppertroposphere，theanticycloneeasttoPhilippinessplitintotwocenters，andthewestoneenhancedwiththedecreaseoftheeast，whichinducednortherlywind’SoccurrenceThedifferenceofsensibleheatOV