简介：BasedontheNCEP/NCARreanalysisdataandtheobservedprecipitationdatainthesouthofChinafrom1958to2000,theimpactof30to60dayoscillationofatmosphericheatsourcesonthedroughtandfloodeventsinJuneinthesouthofChinaisdiscussed.Duringtheflood(drought)events,thereexistsananomalouslow-frequencyanticyclone(cyclone)atthelowlevelofthetroposphereovertheSouthChinaSeaandthenorthwesternPacific,accompaniedwithanomalouslow-frequencyheatsinks(heatsources),whilethereexistsananomalouslow-frequencycyclone(anticyclone)withanomalousheatsources(sinks)overtheareafromthesouthofChinatothesouthofJapan.Onaverage,thephaseevolutionofthelow-frequencyindroughteventsis7to11daysaheadofthatinfloodeventsinMaytoJuneinthesouthofChina.Infloodevents,low-frequencyheatsourcesandcyclonesarepropagatednorthwardfromthesouthernSouthChinaSea,northwestwardfromthewarmpoolofthewesternPacificandwestwardfromthenorthwesternPacificaround140°E,whichhaveveryimportantimpactontheabundantrainfallinJuneinthesouthofChina.However,indroughtevents,thenorthwardpropagationsofthelow-frequencyheatsourcesandcyclonesfromtheSouthChinaSeaanditsvicinityareratherlatecomparedwiththoseinfloodevents,andthereisnoobviouswestwardpropagationoftheheatsourcesfromthenorthwesternPacific.Thetimingofthelow-frequencyheatsourcepropagationhasremarkableimpactontheJunerainfallinthesouthofChina.

简介：热带气旋(TC)的几何特征以前在华南乍见陆地看用基于地面的雷达反射率被检验。中部、吝啬的眼睛区域与TC紧张减少，这被发现，除了严重台风范畴，并且眼睛尺寸与高度增加。眼睛尺寸的增加的率在上面的层是相对更大的。而且，在垂直方向的眼睛尺寸变化的比率不与TC相关紧张。没有关系在垂直方向和垂直的风在眼睛尺寸变化的比率之间被介绍砍。在在在某个水平的眼睛尺寸和眼睛尺寸的垂直变化之间的关系都没被发现，与另外的研究不一致。没有关系在眼睛尺寸和紧张趋势在垂直变化之间存在。主要从0.5～0.7的眼睛圆价值范围，和更强烈的TC通常有更圆形的眼睛。

简介：热带降雨测量的每日、每周的海表面温度数据扫描观察系统传感器的辐射计地球的使命(TRMM)微波成像器和先进微波被用作在mesoscale内在的海表面强迫模仿越过华南海搬到2003的台风Dujuan的数字模型。数字结果在大气的风地里处于差别在台风中心结果附近显示出那不同SST，显示模型有对SST的快、明显的回答。不同SST在某种程度上影响Dujuan的紧张和轨道并且在眼睛附近在它的降水和潜伏的热流动上有重要影响。对Dujuan的SST影响被改变在海洋表面和空气之间的潜伏的热流动在上面主要完成。

简介：Basedon6-hourlysensibleheatfluxandlatentheatfluxfromtheNCEPClimateForecastSystemReanalysis(CFSR)andcirculationdatafromtheJapanese25-yearReanalysis(JRA-25),theinitialdevelopingprocessoftropicalcycloneMindulle(1005)in2010hasbeendiagnosedtorevealtheimpactofair-seainteractionovertheSouthChinaSea(SCS)onthegenesisofitsincipientvortex.TheresultsshowthattheincipientvortexfirstoccurredeastoftheLuzonIslandon0000UTC20August,suggestingthatthetopographicforcingoftheLuzonIslandforeasterlywindsoverthewesternPacificmightbeoneofthefactorsresponsiblefortheformationoftheincipientvortex.Duringtheformationstageoftheincipientvortex,strongsoutheasterliesovertheSCScausedwarmwaterofthemiddleandeasternSCStoflowtowardtheLuzonIslandduetoEkmantransportresultingfromwindstress,leadingtoanincreaseoftheseasurfacetemperatureandsensibleheatfluxintotheatmosphere.Althoughtheanomaloussensibleheatingfavoredsurfacepressuretoreduce,itwasnotconducivetotheincreaseoflocalvorticityassociatedwiththevortexabovetheheatingareabecause,accordingtotheatmosphericthermaladaptationtheory,theanticyclonicvorticitywouldbecreatedinthelowertroposphereduetothedecreasedverticalgradientofthesensibleheating.However,theascendingmotionsoccurredovertheeasternareaoftheanomaloussensibleheatingduetotheaugmentationofthevorticityadvectionwithincreasingheight,causingwatervaportocondenseinthemiddleanduppertroposphere.Inturn,cyclonicvorticitywasgeneratedinthelowertroposphereduetotheincreasedverticalgradientofthecondensationlatentheating,resultingintheformationandfurthergrowthoftheincipientvortex.Therefore,thevorticitycreationduetothecondensationheatingplayedadominantroleduringthesubsequentenhancingstageoftheincipientvortex.

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简介：TheonsetofSouthChinaSeasummermonsoonin1998occurredonMay21st.UsingtheU.S.NationalCentersforEnvironmentalPredictionreanalysisdata,thispaperexaminesthephysicalprocessoftheweakeningofasubtropicalanticycloneinWestPacificduringtheonsetperiodusingtheZwack-Okossivorticityequation.Resultsshowthatduringthepre-onsetperiod,thepositivevorticityadvectioninfrontofanuppertropospherictroughwasthemostdominantphysicalmechanismfortheincreaseofthecyclonicvorticityonthe850-hPalayerovertheSouthChinaSeaanditsnearbyregion.Thesecondarycontributiontotheincreaseofthecyclonicvorticitywasthewarm-airadvection.Aftertheonset,themagnitudeofthelatent-heatwarmingtermrapidlyincreasedanditseffectontheincreaseofthecyclonicvorticitywasaboutthesameasthepositive-vorticityadvection.Theadiabatictermanddivergencetermcontributednegativelytotheincreaseofthecyclonicvorticitymostofthetime.Thus,thepositivevorticityadvectionisthemostimportantphysicalmechanismfortheweakeningoftheWestPacificsubtropicalanticycloneovertheSouthChinaSeaduringtheonsetperiod.

简介：mesoscale表面气象站的观察数据和广东省的天气雷达被采用分析传送对流的不对称的分发在以前，在期间并且在以后乍见陆地为在2006.The结果在华南海岸上乍见陆地做的Chanchu和Prapiroon的热带气旋证明那强壮的传送对流位于landfallingChanchu和Prapiroon的东方、北的部门，也就是在前面和TC的正确部分追踪，为时间starti的一个时期他们的传送对流也在垂直方向有不同差别。尽管，分析显示了那乍见陆地Chanchu和Prapiroon有传送对流的一样的不对称的分发，原因不是一模一样的。在Chanchu的情况中的传送对流的不对称的分发主要与大环境垂直的风的影响被相关砍，低级的水平风砍，并且低级集中和分叉。然而，在Prapiroon的情况中，传送对流的不对称的分发主要与低级集中和分叉的影响被联系。

简介：ByusingtheNCEPreanalysisdatasetin1979-1995,thefluxesofthelatentheat,thesensibleheatandthenetlong-waveradiationintheSouthChinaSea(SCS)areexpandedbymeansofEOFinordertodiscussthebasicclimatologicalfeaturesintheSCS.Thedetailedanalysisshowsthattheair-seaheatexchangesindifferentSCSregionshavedifferentseasonalvariations.ThemiddleandthenorthoftheSCSarethehighvalueregionsoftheair-seaheatexchangesduringthewinterandthesummermonsoonperiods,respectively,theseasonalvariationsofair-seaheatexchangesinthesouthoftheSCSaresmall.Inaddition,theproportionsofdifferentcomponentsinthetotalair-seaheatexchangeshavedifferentseasonalvariationsindifferentregions.TheresultsshowthattheSCSmonsoonandtheair-seaheatexchangesintheSCSregionaretheaccompanimentsofeachother,thegreatdifferenceofthesensibleheatfluxbetweentheIndochinaPeninsulaandtheSCSbeforetheSCSsummermonsoononsetmaybeoneofthetriggersofthelatter.Theremaintainsahighvaluecenterofthesensibleheatfluxbeforethe13thdekad,itsdisappearingtimeconsistswiththatofthesummermonsoononset.ItmeansthatasfarastheSCSlocalconditionsareconcerned,thenorthwestoftheIndochinaPeninsulaisprobablyasensitiveregiontotheSCSsummermonsoononsetandthelandmayplayaleadingroleintheSCSsummermonsoononset.

简介：Theintraseasonaloscillation(ISO)oftheSouthChinaSea(SCS,105-120°E,5-20°N)convectionanditsinfluencesonthegenesisandtrackofthewesternNorthPacific(WNP)tropicalcyclones(TCs)wereexplored,basedonthedailyaverageofNCEP/NCARreanalysisdata,theOLRdataandthewesternNorthPacifictropicalcyclonebest-trackdatafrom1979to2008.ThemechanismoftheinfluencesofISOonTCmovementandthecorrespondinglarge-scalecirculationwerediscussedbyatrajectorymodel.Itwasfoundasfollows.(1)DuringtheSCSsummermonsoon,theSCSconvectionexhibitstheISOfeatureswithactivephasesalternatingwithinactivephases.Themonsooncirculationpatternsaresignificantlydifferentduringthesetwophases.WhentheSCSconvectionisactive(inactive),theSCS-WNPmonsoontroughstretcheseastward(retreatswestward)duetotheactivity(inactivity)ofSCSmonsoon,andtheWNPsubtropicalhighretreatseastward(stretcheswestward),whichenhances(suppresses)themonsooncirculation.(2)TheamountofTCgenesisintheactivephaseismuchmorethanthatintheinactivephase.AmajorityofTCsformwestof135°Eduringtheactivephasesbuteastof135°Eintheinactivephases.(3)TheTCsenteringtheareawestof135°Eandsouthof25°NwouldmovestraightintotheSCSintheactivephase,orrecurvenorthwardintheinactivephase.(4)Simulationresultsshowthatthesteeringflowassociatedwiththeactive(inactive)phasesisinfavorofstraight-moving(recurving)TCs.Meanwhile,theimpactsofthelocationsofTCgenesisonthecharacteristicsofTCtrackcannotbeignored.TCsthatoccurredfatherwestwardaremorelikelytomovestraightintotheSCSregion.

简介：ASouthChinaSea(SCS)localTC(SLT)isdefinedasatropicalcyclone(TC)thatformswithintheSCSregionandcanreachthegradeoftropicalstorm(TS)orabove.ThestatisticalfeaturesoftheSLTsfrom1985to2007areanalyzedfirst.ItisfoundthatovertheSCSabout68%oftheTCscandevelopintoTSs.TheSLTintensityisrelativelyweakandassociatedwithitsgenesislatitudeaswellasitstrack.TheSLTmonthlynumberpresentsaseasonalvariationwithtwopeaksinMayandJulytoSeptember.BasedonthedailyheatfluxdatafromtheWoodsHoleOceanographicInstitution_ObjectivelyAnalyzedair-seaFluxes(WHOI_OAFlux)inthesameperiod,theair-seaexchangeduringtheprocessofgenerationanddevelopmentoftheSLTisstudied.Resultsshowthattheheatfluxesreleasedtotheatmosphereincreasesignificantlydaybydaybeforecyclogenesis.TheoceantothesouthtotheTCcenterprovidesthemainenergy.AlongwiththedevelopmentofSLT,theregionswithlargeheatfluxesspreadclockwisetothenorthofTC,whichreflectstheenergydispersionpropertyofvortexRossbywavesintheperipheryoftheTC.OncetheSLTformstheheatfluxesarenotintensifiedasmuch.Duringthewholeprocess,thenetheat,latentheatandsensibleheatfluxdisplayasimilarevolution,whilethelatentheatfluxmakesamaincontributiontothenetheatflux.Themaximumair-seaheatexchangealwaysoccursattheleftsideoftheTCmovingdirection,whichmayreflecttheinfluenceoftheSCSsummermonsoononTCstructure.

简介：AnapproachisproposedforpredictingturningandaccelerationmotiontrendofthetropicalcyclonesovertheSouthChinaSeafor72hintheextrapolatedtrackcoordinates.Cross-track(CT)andalong-track(AT)componentsaredefinedaccordingtothepersistentlyextrapolatedtrackcoodinatesbasedonobservedpositionsattheinitialandpast24htimes.Akindofstraight-forwardmeasuremaybeprovidedwithCTandATcomponentsfortyphoonturningmotionandac-celerationmotion.Canonicalcorrelationanalysis(CCA)isperformedtorevealthecorrelaotionsbe-tweentropicalcyclonetracksandenvironmental500hPageopotentialheightfields.Astepwisedis-criminateanalysistechniqueisadoptedtoderivetheclassificationfunctionsoftherespectivethreecategoriesforATandCTcomponents.Especially,categoricalcombinationsofCTandATcompo-nentsaredividedintopossible9regionscorrespondingwithtropicalcyclonebehaviors.Notonlycan9motiontrendsofatropicalcyclonebepredicted,butalsothelocationanditsmaximumerroratleastincertaindirectionareavailable.Theperfectprediction(PP)verificationsindicatethatthepercentcorrectsfortheCTandATcategoriesare67%and69%intheindependentsamples,73%and53%inthedependentsamples,respectively,higherthanthatof33.3%forrandomchance;moreover,therateforsuccessfullyforecastingthatinwhichoneofthenineregionsthetropicalcy-cloneswillfallat72hisabout40%,alsohigherthanthestochasticprobabilityof11%.Themethodhasbeenprovedtobeskillfulandpromising.

简介：BasicclimaticcharacteristicsareanalyzedconcerningtheprecipitationanomaliesinrainingseasonsoverregionssouthoftheChangjiangRiver(theYangtze).ItfindsthattheregionsaretheearliestineasternChinawhererainingseasonsbeginandend.Precipitationtheretendstodecreaseoverthepast50years.Watersboundedby9(S-1(S,121(E-129(EarethekeyzonesofSSTanomaliesthataffecttheprecipitationintheseregionsoverMay~Julyinprecedingyears.Long-termair-seainteractionsmakeitpossibleforprecedingSSTanomaliestoaffectthegeneralcirculationthatcomeafterwards,causingprecipitationanomaliesintherainingseasonsinregionssouthoftheChangjiangRiverinsubsequentyears.

简介：85-stationdailyprecipitationdatafrom1961-2010providedbytheNationalMeteorologicalInformationCenterandtheNCEP/NCAR2010dailyreanalysisdataareusedtoinvestigatethelow-frequencyvariabilityontheprecipitationofthefirstrainseasonanditsrelationshipswithmoisturetransportinSouthChina,andchannelsoflow-frequencywatervaportransportandsourcesoflow-frequencyprecipitationarerevealed.Theannuallyfirstrainingseasonprecipitationin2010ismainlycontrolledby10-20dand30-60doscillation.Therainfallismore(interrupted)whenthetwolow-frequencycomponentsareinthesamepeak(valley)phase,andtherainfallislesswhentheyaresuperposedintheinversephase.The10-20dlow-frequencycomponentofthemoisturetransportismoreactivethanthe30-60d.The10-20dwatervaporsourceslieintheSouthIndiaOceannear30°S,theareabetweenSumatraandKalimantanIsland(thesouthwestsource),andtheequatorialmiddlePacificregion(thesoutheastsource),andtherearecorrespondingsouthwestandsoutheastmoisturetransportchannels.Byusingthecharacteristicsof10-20dwatervaportransportanomalouscirculation,thecorrespondinglow-frequencyprecipitationcanbepredicted6dahead.

简介：大雨的三维的风领域在2005年6月12-13日与位于Meizhou和Shantou的城市的dual-Doppler雷达的卷扫描数据在广东省被检索并且学习。这被显示出中央--规模和中央--在低、中间的层位于对流系统的规模集中线在重降雨起一个重要作用。集中线是雨的开始并且维持的机制。三个维的运动学的结构模型也被给。

简介：UsingtheInternationalComprehensiveOcean-AtmosphereDataSet(ICOADS)andERA-Interimdata,spatialdistributionsofair-seatemperaturedifference(ASTD)intheSouthChinaSea(SCS)forthepast35yearsarecompared,andvariationsofspatialandtemporaldistributionsofASTDinthisregionareaddressedusingempiricalorthogonalfunctiondecompositionandwaveletanalysismethods.TheresultsindicatethatbothICOADSandERA-InterimdatacanreflectactualdistributioncharacteristicsofASTDintheSCS,butvaluesofASTDfromtheERA-InterimdataaresmallerthanthoseoftheICOADSdatainthesameregion.Inaddition,theASTDcharacteristicsfromtheERA-Interimdataarenotobviousinshore.Aseesaw-type,north-southdistributionofASTDisdominantintheSCS;i.e.,apositivepeakinthesouthisassociatedwithanegativepeakinthenorthinNovember,andanegativepeakinthesouthisaccompaniedbyapositivepeakinthenorthduringAprilandMay.InterannualASTDvariationsinsummerorautumnaredecreasing.Thereisaseesaw-typedistributionofASTDbetweenBeibuBayandmostoftheSCSinsummer,andthecenteroflargevaluesisintheNanshaIslandsareainautumn.TheASTDintheSCShasastrongquasi-3aoscillationperiodinallseasons,andaquasi-11aperiodinwinterandspring.TheASTDispositivelycorrelatedwiththeNio3.4indexinsummerandautumnbutnegativelycorrelatedinspringandwinter.

简介：ThetimingoftheSouthAsianHigh(SAH)establishmentovertheIndochinaPeninsula(IP)fromApriltoMayanditsrelationstothesetupofthesubsequenttropicalAsiansummermonsoonandprecipitationovereastern-centralChinainsummerareinvestigatedbyusingNCEP/NCARdailyreanalysisdata,outgoinglongwaveradiation(OLR)dataandthedailyprecipitationdatafrom753weatherstationsinChina.ItisfoundthatthetransitionsofthezonalwindverticalshearandconvectionestablishmentovertropicalAsiaareearlier(later)intheyearsofearly(late)establishmentofSAH.Inthelowertroposphere,anti-cyclonic(cyclonic)anomalycirculationdominatestheequatorialIndianOcean.Correspondingly,thetropicalAsiansummermonsoonestablishesearlier(later).Furthermore,theatmosphericcirculationandthewatervaportransportintheyearsofadvancedSAHestablishmentaresignificantlydifferentfromthedelayedyearsinAsiainsummer.Out-of-phasedistributionofprecipitationineastern-centralChinawillappearwithaweak(strong)SAHandwesternPacificsubtropicalhigh,strong(weak)ascendingmotionintheareasouthofYangtzeRiverbutweak(strong)ascendingmotionintheareanorthofit,andcyclonic(anti-cyclonic)watervaporfluxanomalycirculationfromtheeastern-centralChinatowesternPacific.Accordingly,thetimingoftheSAHestablishmentattheupperlevelsofIPisindicativeofthesubsequentonsetofthetropicalAsiansummermonsoonandtheflood-droughtpatternovereastern-centralChinainsummer.