夏季亚洲—太平洋涛动与大气环流和季风降水

X1,222223ZHAOPing1,2CHENJunmin2XIAODong2NANSulan2ZOUYan2ZHOUBotao31.,,1000812.,,1000813.,,1000811.StateKeyLaboratoryofSevereWeather,ChineseAcademyofMeteorologicalSciences,Beijing100081,China2.InstituteofClimateSystem,ChineseAcademyofMeteorologicalSciences,Beijing100081,China3.NationalClimateCenter,ChinaMeteorologicalAdministration,Beijing100081,China2008208204,2008209217.ZhaoPing,ChenJunmin,XiaoDong,NanSulan,ZouYan,ZhouBotao.2008.SummerAsian2Pacificoscillationanditsrelation2shipwithatmosphericcirculationandmonsoonrainfall.ActaMeteorologicaSinica,66(5):716-729AbstractUsingtheERA240dataandnumericalsimulations,thisstudyinvestigatedtheteleconnectionovertheextratropicalAsian2PacificregionanditsrelationshipwiththeAsianmonsoonrainfallandtheclimatologicalcharacteristicsoftropicalcyclonesoverthewesternNorthPacific,andanalyzedimpactsoftheTibetanPlateau(TP)heatingandPacificseasurfacetemperature(SST)ontheteleconnection.TheAsian2PacificOscillation(APO)isdefinedasazonalseesawofthetropospherictemperatureinthemidlatitudesoftheAsian2Pacificregion.WhenthetroposphereiscoolinginthemidlatitudesoftheAsiancontinent,itiswarminginthemidlatitudesofthecentralandeasternNorthPacific;viceversa.TheAPOalsoappearsinthestratosphere,butwithareversedphase.UsedasanindexofthethermalcontrastbetweenAsiaandtheNorthPacific,itprovidesanewwaytoexploreinteractionsbetweentheAsianandPacificatmosphericcirculations.TheAPOindexexhibitstheinterannualandinterdecadalvariability.Itshowsadownwardtrendduring1958-2001,indicatingaweakeningofthethermalcontrast,andshowsa5.52yearoscillationperiod.TheformationoftheAPOisassociatedwiththezonalverticalcirculationcausedbyadifferenceinthesolarradiativeheatingbetweentheAsiancontinentandtheNorthPacific.ThenumericalsimulationsfurtherrevealthatthesummerTPheatingenhancesthelocaltropospherictempera2tureandupwardmotion,andthenstrengthensdownwardmotionanddecreasesthetropospherictemperatureoverthecentralandeasternNorthPacific.ThisleadstotheformationoftheAPO.ThePacificdecadaloscillationandElNi‰no/LaNinaoverthetropicaleasternPacificdonotexertstronginfluencesontheAPO.WhenthereisananomalyinthesummerAPO,theSouthAsianhigh,thewesterlyjetoverEurasia,thetropicaleasterlyjetoverSouthAsia,andthesubtropicalhighovertheNorthPacificchangesignificant2ly,withanomalousAsianmonsoonrainfallandtropicalcycloneactivitiesoverthewesternNorthPacific.ThesummercoolingalongtheupperandmiddlereachesoftheYangtzeRiverinthepast40moreyearsisrelatedtotheAPO,whichispossiblyaregionalre2sponsetothedecadalvariabilityoftheglobalatmosphericcirculation.AnanomaloussignaloftheAPOmaypropagatetotheArcticandAntarctic.Moreover,theAPOalsoappearsinotherseasons.KeywordsAsian2Pacificoscillation(APO),Atmosphericcirculation,Monsoonrainfall,TropicalcycloneactivitiesERA240,,(SST),:(Asian2PacificOscillation,APO),,,;,APO057726619/2008/66(5)20716229ActaMeteorologicaSinicaX:/(GYHY200706005):,E2mail:[e-mail].©1994-2009ChinaAcademicJournalElectronicPublishingHouse.Allrightsreserved.:,,APO;APOAPO,,40APO,APO,,,,P62.4+11,()Huang(1987)/(EAP),Nitta(1987)(PJ),:,,,Lau(1992,2002,2004),,Rodwell(2001),Zhao(2001),3,(2006),2,2,Ding(2005),5,,,:,,,,??,Zhao(2007b),2,2,,(T)T=T-T,T,TT4500m,,ERA240(Uppala,etal,2005)500200hPaT68(1a),T,,,T,T(Zhao,etal,2007b),500200hPa717:©1994-2009ChinaAcademicJournalElectronicPublishingHouse.Allrightsreserved.(a)19582001500200hPaT()(;1500m)(Zhao,2007b);(b)19582001500200hPaTEOF1(0.01,0);(c)19582001500200hPaT()(Zhao,2007b)Fig.1(a)Climatologyofthesummermeanupper2tropospheric(500-200hPa)T()fortheperiod1958-2001(twoboxesrepresenttheregionsofAsiaandtheNorthPacific,respectively,andthethickdashedlinesindicatethetopographiccontourof1500m)Zhaoetal.,2007b);(b)EOF1ofthesummermeanupper2tropospheric(500-200hPa)fortheperiod1958-2001(scaledby0.01,theshadedareaisgreaterthanzero);and(c)thesummermeantimeseriesoftheupper2tropospheric(500-200hPa)T()overAsiaandtheNorthPacific(Zhaoetal.,2007b)817ActaMeteorologicaSinica2008,66(5)©1994-2009ChinaAcademicJournalElectronicPublishingHouse.Allrightsreserved.(EOF)1958200168500200hPaT,:1(EOF1)25%,213%North(1982)EOF1EOF2,EOF1EOF2,MonteCarloEOF199%EOF1(1b),0.01,0.03,-0.01,-0.03,,Zhao(2007b)1a1b,1550N60120E(1550N180120W)(1a)500200hPaT()1c,T,-0.78,44,38,6,6T(99%),,-0.72,2070,EOF1,ERA2401958197519762001EOF,EOF1()1a;,NCEPCCSM(),EOF1,T,T(),T(),,EOF1,(Asian2PacificOscillation,APO),500200hPaT,:IAPO=T(60120E,1550N)-T(180120W,1550N),,1bEOF1(0.91),,0.87EOF1,APOAPO(2a),1975,15,2,TT;1975,,22,5,TTNCEP(),19582001,APO5.5a(95%)2b,,,850200hPa,,APOT,,,,APO110E(2c),1,30N,0.8208090APO(2a),,,(,2004),(APO),917:©1994-2009ChinaAcademicJournalElectronicPublishingHouse.Allrightsreserved.(a)APO()(Zhao,etal,2007b);(b)APOT()30N;(c)APOT()110E(95%,)Fig.2(a)TimeseriesofthesummermeanAPOindex()(Zhaoetal.,2007b);(b)height2longitudecrosssectionoftheregressedsummerT()againsttheAPOindexalong30N;(c)sameas(b)butfortheheight2latitudecrosssectionalong110E(Thelightshadedareasaresignificantatthe