干旱災害會場s511.3上午ao與中低緯氣候

AO對亞洲中低緯地區(qū)氣候的影響龔道溢北京師范大學地表過程與資源生態(tài)國家重點實驗室冬、春季AO信號的傳播途徑印度洋大氣、海洋響應西南干旱南方極端降水南海氣候東亞夏季風冬、春季AO信號的傳播途徑3條可能途徑：高緯波列、南支波列、北太平洋偶極型環(huán)流850winds,500hPaheights,surfacetemperatureinassociationwith-AOWinterseasons.-AO:西伯利亞高壓強、冬季風強南支波列：

-印度洋海氣狀況-西南干旱-南方極端降水-南海氣候1990,1993and20021979,1980and2001ChangesofE-vectors,eddykineticenergy(shadings)andseasonalmeancirculationstreamlines(smoothlineswitharrows)inMAMat200hPa.Allareshownasanomaliesinassociationwithaone-unit-largerMAMAOindex.MaximumE-vectoranomalyis+10.1m2/s2.北太平洋偶極型環(huán)流-東亞夏季風冬、春季AO信號的傳播途徑印度洋大氣、海洋響應西南干旱南方極端降水南海氣候東亞夏季風Vor.15-25N,50-70E,850-200hPaR(AO,CMAP)=+0.56R(AO,OLR)=-0.61Anomaliesofthe20Cisothermdepth(contourshadings,inmeters)andwindstresses(vectors,inNm-2)correspondingtooneunitofAOindexduringJFM.Theclimatemeandepthof20Cisothermsmallerthan100mareoverlaidascontour.Onlyanomalouswindstressandisothermsignificantatthe95%levelareplotted.RuiandWang1990;LaurenceandWebster,2002CMAPasaproxyoflatentheatingAO-relatedchangesinBCM21851-1999Interannual,IOD&ENSOremovedAnomaliesofseawatertemperaturebetween5S-10SinassociationwithoneunitofJFMAOindexforeachtwo-monthsegmentsfromMarchthroughOctober.Significant(atthe95%level)valuesareshaded.Solidlinesindicatetheclimatemeandepthof20Cisotherm.CorrelationofJFMAOindexwithSSTanomaliesforeachtwo-monthsegmentsfromMarchtoOctober.Valuessignificantatthe95%levelareindicatedbyshadings.Zerolinesareomittedforbrevity.TimeseriesofregionalmeanJJASSTsandSSTtendencyoverwesterntropicalIndianOcean(10S-10N,40E-60E).TheJFMAOisplottedtogetherforcomparison.SSTtendencyisdefinedasthedifferenceofSSTanomalies(June-July-AugustminusApril-May).The2009/2010droughtoversouthwesternChinahasbeenthedriesteventwiththeminimumpercentagerainfallanomalyandthemaximumnon-raindaysduringwinterseason(Oct.-Feb.)inthepast50years,andalsotheseverestwiththelowestpercentagerainfallanomalyatthesameperiodsince1880.Thedroughtdomainischaracterizedwithanomalouswarminganddryinginthemid-lowertroposphereClimatologicalmeanduringdroughtperiodThenormalizedregressedcirculationsassociatedwithnegative-phaseAOComposite500hPageopotentialheightisoline(5875geopotentialmeter)duringthedroughtperiod(Oct.-Feb.)

Among287stations,238(230)stationshavepositivecorrelationand82(92)stationsarepositivelysignificantabovethe95%confidencelevelforP80thandprecipitationamount,respectivelyThetimeseriesofAOandP80thandprecipitationamountoverthecentral-southernChinaduringJanuarytoFebruaryENSO-excludedseriesOriginalseriesP80th?0.54a(0.43a)0.49a(0.38a)P90th?0.54a(0.44a)0.47a(0.38a)PrecipitationAmount?0.50a(0.38a)0.45a(0.31a)StrongSBTFrequency0.55a0.55aa:significantatthe95%confidencelevelCorrelationsofprecipitationamountandfrequenciesofextremeprecipitationwithAOduringJFAO-relatedclimatechangesonsynopticscaleDailysouthbranchtrough(SBT)index:V700(region1)–V700(region2)12Corr(AO,SBT)=0.55Corr(P80th,SBT)=0.55Weatherdisturbancesaredefinedas

thevarianceofthehigh-passfiltercomponentsofomegabetween700-500hPalevels27%+-++--MAM冬、春季AO信號的傳播途徑印度洋大氣、海洋響應西南干旱南方極端降水南海氣候東亞夏季風38Q1-Q2sensible+latentheatIntegratedQ1-Q2fromsurfaceto200hPaComposites:1982,1990,2002,2003,2007394041Controlrun:reanalysisatmosphereFoursensitiveruns:March1–April30;1981,1991,2001,2004,‘neutralyears’AO-atmosphericforcing,120E-120W,0-65N,2windfluxesEachexperimentrunsfor10yr.42SimulatedSSTanomalies.The10-yearsensitiveintegrationminusthe10-yearcontrolruns43Simulated850hPawindanomalies.The10-yearsensitiveintegrationminusthe10-yearcontrolruns44Observation:

Winter/springAOissignificantlycorrelatedwithEastAsiansummerclimateChangesinsummerprecipitation(mm)correspondingtoaonestandarddeviationoftheMayAOindexfortheperiod1900-1998.Greysquaresindicatethegridswithdataavailabilityabove95%intheentireperiod.Regionsabove95%confidencelevelareshaded..Contourintervalis10

mm.Zerocontoursareomitted.45Statisticalapproach:ENSO:~40%EASMinterannualvarianceMAMAO:~19%(GongandHo,2003)Ref.GongDao-Yi,YongqiGao,DongGuo,RuiMao,JingYang,MiaoHu,MiaoniGao.InterannuallinkagebetweenArctic/NorthAtlanticOscillationandtropicalIndianOceanprecipitationduringborealwinter.ClimateDynamics,2014,42,1007-1027,DOI:10.1007/s00382-013-1681-4Miao-NiGao,JingYang,Dao-YiGong,andSeong-JoongKim.UnstablerelationshipbetweenspringArcticOscillationandEastAsiansummermonsoon.InternationalJournalofClimatology,2014,34,2522-2528,DOI:10.1002/joc.3849GongDao-Yi,YongqiGao,MiaoHu,DongGuo.AssociationofIndianOceanITCZvariationswiththeArcticOscillationduringborealwinter.AtmosphericandOceanicScienceLetters,2013,6,300-305,doi:10.3878/j.issn.1674-2834.12.0108YangJ,GongDY,WangWS,HuM,MaoR.Extremedroughteventof2009/2010oversouthwesternChina.MeteorologyandAtmosphericPhysics,2012,115:173-184,doi10.1007/s00703-011-0172-6MaoR,GongDY,YangJ,BaoJD.LinkagebetweentheArcticOscillationandwinterextremeprecipitationovercentral-southernChina.ClimateResearch,2011,50,187-201,C1041,doi:10.3354/cr01041Ref.GongDY,JYang,SJKim,YGao,DGuo,TZhou,MHu.SpringArcticOscillation-EastAsiansummermonsoonconnectionthroughcirculationchangesoverthewesternNorthPacific.ClimateDynamics,2011,37:2199-2216,doi:10.1007/s00382-011-1041-1GongDY,SJKim,CHHo.ArcticandAntarcticOscillationsignaturesintropicalcoralproxiesovertheSouthChinaSea.AnnalesGeophysicae,2009,27,1979-1988GongDY,SJKim,CHHo.ArcticOscillationandiceseverityintheBohaiSea,EastAsia.InternationalJournalofClimatology,2007,27,1287-1302,doi:10.1002/joc.1470GongDY,RMaoR,andYDFan.E