太平洋—印度洋海温与我国东部旱涝型年代际变化的关系

12220073ClimaticandEnvironmentalResearchVol112No12Mar120072006201216,200720121040233033KZCX32SW2226,,1981,,E2mail:guwei@mail1iap1ac1cn1,21,311,1000292,1000493,211101,282070,70;,,,2(SSTA)100629585(2007)0220113211P461ARelationshipbetweenInterdecadalVariationofNorthPacific2EquatorialIndianOceanSSTandTransitionofRainfallPatterninEastChinaaroundthe1970sGUWei1,2,LIChong2Yin1,3,andPANJing11StateKeyLaboratoryofNumericalModelingforAtmosphericSciencesandGeophysicalFluidDynamics,InstituteofAtmosphericPhysics,ChineseAcademyofSciences,Beijing1000292GraduateUniversityoftheChineseAcademyofSciences,Beijing1000493MeteorologicalCollege,PLAUniversityofScienceandTechnology,Nanjing211101AbstractOrthogonalwaveletanalysisofsummerrainfallinEastChinashoweditsoppositespatialpatternbeforeandafterthe1970s,mainlytheoppositesituationofprecipitationinNorthChinaandinthemiddleandlowerreachesoftheYangtzeRiver1ThedifferenceofmeridionalpositionofthesummerEastAsianupper2troposphericJetStream(EAJS)andWestPacificSubtropicalHigh(WPSH)beforeandafterthe1970swasoneofthemostimportantrea2sonsforthetransitionofsummerrainfallpattern1Besides,oninterdecadaltimescales,NorthPacificandTropicalIndianOceanSeaSurfaceTemperatureAnomaly(SSTA)variatedcoherently,andwerecloselyrelatedtothetransi2tionofsummerrainfallpatterninEastChina1What’smore,NorthPacific2EquatorialIndianOceanSeaSurfaceTem2peratures(SST)showedacertainrelationshipwiththenorth2southmovementofEAJSandWPSHonbothinteran2nualandinterdecadaltimescales1Thus,NorthPacific2EquatorialIndianOceanSSTwasindeedanimportantfactorClimaticandEnvironmentalResearch12Vol112forthepredictionofsummerrainfallpatterninEastChina1KeywordsNorthPacific,TropicalIndianOcean,rainfallpattern,EastAsiajetstream,subtropicalhigh1,,,,2070,(),,[1,2],,70,[35],,,[6][1]Hu[7],Hadley,[8](PDO)ENSO[9],1976,(SSTA),,,,?,,,,,2870,SSTA,70,SSTA,,,,,,SSTA216054(19512004);Hadley1118702003;NCAR/NCEP19482004215215PDOMantua[10]4::16;:11;:4112No12:GUWei,etal.RelationshipbetweenInterdecadalVariationofNorthPacific2EquatorialIndian14;:17,db16[11],SSTA,morlet,2070200hPa500hPa850hPa19512000Mantua[10]PDO,,SS2TASSTA,,,SSTA,200hPa500hPa850hPa32050608090,db16428,1,,10%,,70,712%517%,11957197119831999,,(2),;,,,419571971198319992070,SSTA200hPa500hPa850hPa1428Fig11Componentsretainingvariabilitiesontimescaleslargerthan282yearofsummerrainfallinthefourregions511ClimaticandEnvironmentalResearch12Vol1122160:(a)19571971;(b)19831999Fig12Summerrainfallof160stationsinChina:(a)averageof19571971;(b)averageof198319993(a)19571971(b)19831999SSTA(95%,:)Fig13AverageSSTAfieldof(a)19571971and(b)19831999(Shadedareasaresignificantat95%level,units:)4113,SSTA19571971,,,(PDO)[10];,19831999,,,PDO;,SSTA()SSTA,19571971,;19831999Kawamura[12]R2EOF,ENSO,6112No12:GUWei,etal.RelationshipbetweenInterdecadalVariationofNorthPacific2EquatorialIndianENSO,,,SSTA,3,70SSTA95%,(10S10N,60100E)SSTA(ITIO),SSTA(IPDO)SSTA,IPDOITIO28(4),SSTA,3112%4818%,60aSSTA,5aPDO,90%4PDO()SSTA()SSTA()28Fig14Componentsretainingvariabilitiesontimescaleslargerthan282yearofPDOindex(dashedcurve),TropicalIndianOceanSSTAindex(dottedcurve)andNorthPacific2TropicalIndianOceanSSTAindex(solidcurve)5(a)PDO(b)SSTA(95%90%)Fig15GlobalwaveletSpectrumsfor(a)PDOindexand(b)TropicalIndianOceanSSTAindex(solidcurveanddashedcurvesindi2cate95%and90%confidencelevels,respectively)711ClimaticandEnvironmentalResearch12Vol112,PDO56a,PDO5070a[13,14],SSTA(5b),SSTA60a,4SSTA62SSTAIPISSTA(95%,:)Fig16CorrelationmapofNorthPacific2TropicalIndianOceanSSTAindexandglobalSSTA(Shadedareaindicates95%significancelevel,units:)4,IPDOITIO,,70,SSTA,70,,,(1920),,,,,IPDOITIO(19012004)9,0137,99%,SSTA,(9)(28),,(10S10N,60100E)(2545N,150E150W)SSTA:2SSTA(IPI),SSTAIPDOITIO,01880177,SSTASSTA(6),,SSTASSTA,SSTA4SSTA28,3917%,,43,2SSTAPDOSSTA,2070,SSTA,SSTA(5)412,8112No12:GUWei,etal.RelationshipbetweenInterdecadalVariationofNorthPacific2EquatorialIndian,,,3,5,30N,6[15,16]7,,,[17]7(a)200hPa(:ms-1)(b)500hPa(:gpm)1983199919571971(95%90%)Fig17Thedifferenceof(a)meridionalwindat200hPa(units:ms-1)and(b)geopotentialheightat500hPa(units:gpm)between19831999and19571971(Darkandlightshadedareasindicate95%and90%significancelevels,respectively),[16],,,,;,[18,19]40N,1983199919571971(7a),,,70,,,413,,,911ClimaticandEnvironmentalResearch12Vol112,,7b1983199919571971500hPa,70,,70,,NCEP[20],,70,,ERA240200hPa500hPa(1983199919581971)500hPa(7b)ERA240,NCEPNCEP,,200hPa40N,,70,70,70,53SS2TA(IPI)200hPa500hPa850hPa,2SSTA,IPI200hPa500hPa850hPa9,,,,,,Hadley,SSTA[21],[18]SSTA,,[22],IPI200hPa500hPa850hPa(8),8a40N,,IPI,IPI8b,32N,,IPI,IPI850hPa(8c),500hPa,IPI,,,,,IPI,,,SS2TA(IPI),,,,,(IPI),,,,4,,70,,,IPI,,70,IPI,0212No12:GUWei,etal.RelationshipbetweenInterdecadalVariationofNorthPacific2EquatorialIndian8IPI(a)200hPa(:ms-1)(b)500hPa(:pgm)(c)850hPa(:ms-1)(IPI9,95%90%)Fig18Regressionfieldof(a)meridionalwindat200hPa(units:ms-1),(b)geopotentialheightat500hPa(units:gpm),and(c)windfieldat850hPa(units:ms-1)uponNorthPacific2TropicalIndianOceanSSTindex[IPIandthethreefieldswere92yearhigh2bandpassedbeforeregression,Darkandlightshadedarea