摘要
TheinterannualvariationsofrainfalloversouthwestChina(SWC)duringspringanditsrelationshipwithseasurfacetemperatureanomalies(SSTAs)inthePacificareanalyzed,basedonmonthlymeanprecipitationdatafrom26stationsinSWCbetween1961and2010,NCEP/NCARre-analysisdata,andHadleyglobalSSTdata.SensitivitytestsareconductedtoassesstheresponseofprecipitationinSWCtoSSTAsovertwokeyoceanicdomains,usingtheglobalatmosphericcirculationmodelECHAM5.TheinterannualvariationofrainfalloverSWCinspringisverysignificant.Therearestrongnegative(positive)correlationcoefficientsbetweentheanomalousprecipitationoverSWCandSSTAsovertheequatorialcentralPacific(themid-latitudePacific)duringspring.NumericalsimulationsshowthatlocalrainfallinthenorthwestoftheequatorialcentralPacificissuppressed,andasubtropicalanticyclonecirculationanomalyisproduced,whileacycloniccirculationanomalyinthemid-latitudewesternPacificoccurs,whentheequatorialPacificSSTAsareinacoldphaseinspring.AnomalousnortherlywindsappearinthenortheasternpartofSWCinthelowertroposphere.PrecipitationincreasesovertheMaritimeContinentofthewesternequatorialPacific,whileacycloniccirculationanomalyappearsinthenorthwestofthewesternequatorialPacific.AtroughovertheBayofBengalenhancesthesoutherlyflowinthesouthofSWC.ThetroughalsoenhancesthetransportofmoisturetoSWC.ThewarmmoistureintersectswithanomalouscoldairoverthenortheastofSWC,andsoprecipitationincreasesduringspring.Ontheinterannualtimescale,theimpactsofthemid-latitudePacificSSTAsonrainfallinSWCduringspringarenotsignificant,becausethemid-latitudePacificSSTAsareaffectedbytheequatorialcentralPacificSSTAs;thatis,themid-latitudePacificSSTAsareafeedbacktothecirculationanomalycausedbytheequatorialcentralPacificSSTAs.
出版日期
2017年02月12日(中国期刊网平台首次上网日期,不代表论文的发表时间)