简介:现在的学习在冬季调查华南海(SCS)SST和ENSO的影响(1月鈥揊ebruary鈥揗arch;JFM)在由为时期使用车站观察的华南和它的动态过程上的降雨1951鈥?003,为时期的遇见的办公室哈德利中心SST数据1900鈥?008,并且为时期的ERA-40分析数据1958鈥?002。在华南上的JFM降雨与Ni有重要关联,这被发现?o-3和SCSSST。分析在ElNi显示出那?o或积极SCSSST异例年,在700hPa的西南的异例在华南海上统治,它接着搬运更多的潮湿进华南并且赞成增加的降雨。部分回归分析显示对冬季降雨的独立ENSO影响主要在华南上发生,而SCSSST在华南的北部分在冬季降雨上有更大的独立影响。在华南上的温度在表面附近在300hPa和增加显示出明显的减少,与Ni导致的前者?o-3和后者SCSSST异例。这提高对流不稳定性并且削弱潜在的涡度(PV),它解释加强在华南上登上运动和JFM降雨的增加。关键词ENSO-华南海-SST-降雨-对流不稳定性-潜在的涡度
简介:Derechos经常发生在欧洲和美国,而是在中国的derechos的报告是少见的。在这份报纸,雷达,卫星,和表面观察,数据被用来在2011年4月17日在华南分析一个derecho事件。对流系统与中等对流可得到的精力在环境形成了的生产derechomesoscale,大垂直的风砍,并且在中间的对流层的干燥的层,并且进行与前面和一根表面风集中线一起向南方。暴风能在雷达回响的特征和强风的原因根据差别被划分成二个阶段。一个阶段是一个supercell阶段,有塑造鞠躬的雷达回响的高降水的supercell的下沉后面的流入在导致了FujitaF0班强风。另外的阶段是一个non-supercell阶段(回响是顺序肾形的,塑造脚,并且一个平常的单个房间),在哪个downbursts在FujitaF1班上导致了强风。这个derecho事件有许多类似,derechos在西方的国家观察了。例如,暴风对吝啬的流动垂直,强风位于鞠躬回响的鼓起的部分,并且derecho移动了与表面前面一起向南方。一些差别也被观察。摘要规模的强迫当进展不在时是弱的高振幅的midlevel马槽并且伴随强壮的表面气旋;然而,垂直的风砍是很强壮的,典型地代表与强壮的摘要规模的强迫联系的derechos的一个特征。对流可得到的势能以前被认为必要到弱强迫的原型和混合derechos的形成的对流可得到的势能和downdraft的极其高的价值;然而,这些价值多不到2000J在这个derecho事件期间。
简介:ThecharacteristicsandpossiblephysicalmechanismofinterdecadalvariationoftheintensityoftheSouthAsianHigh(SAH)insummerareanalyzedusingtheNCEP/NCARreanalysisdataandNOAAextendedreconstructedseasurfacetemperature(SST)data.Theresultsindicatethataremarkableinterdecadaltransitionoccurredinthelate1970sthatincreasedtheintensityofSAH,or,anabruptclimatechangewasaround1978.AcomparativeanalysisbetweentheweakandstrongperiodoftheSAHintensityshowsthattherelatedanomalouspatternsoftheatmosphericcirculation(includingwindfield,airtemperaturefieldandverticalvelocityfield)arenearlyoppositetoeachother.Thesurfacelatentheatfluxanomaliesovertheplateau(especiallyinthenorthwestoftheplateau)insummerexertgreatinfluenceontheinterdecadalvariationoftheSAHintensityandthesurfacesensibleheatfluxanomaliesplayamoreimportantrole.ConsistentwiththeinterdecadalvariationoftheSAHintensity,themonopolemodeofthetropicalIndianOceanSSTinsummeralsoexperiencedalowtohightransitioninthelate1970s.Tosomeextent,thiscanrevealtheimpactoftheanomalousmonopolemodeofthetropicalIndianOceanSSTinsummeroninterdecadalvariationoftheSAH.
简介:Theimpactofstrong(weak)intraseasonaloscillation(ISO)overSouthChinaSea(SCS)andSouthAsia(SA)insummerontheSCSandSAsummermonsoonandthesummerrainfallinEasternChinaarestudiedbyusingtheNCEP-NCARanalysisdataandtherainfalldataof160stationsinChinafrom1961to2010.Itisfoundthattheimpactsaresignificantlydifferentindifferentmonthsofsummer.ThestudyshowsthatinJuneandJulycyclonic(anticyclonic)atmosphericcirculationoverSCSandSAcorrespondstostrong(weak)ISOoverSCS.InAugust,however,strong(weak)ISOoverSCSstillcorrespondstocyclonic(anticyclonic)atmosphericcirculationoverSA.InJuneandAugustcyclonic(anticyclonic)atmosphericcirculationoverSouthAsiacorrespondstostrong(weak)ISOoverSAwhileastrong(weak)ISOcorrespondstoanticyclonic(cyclonic)atmosphericcirculationoverSAinJuly.Besides,inJunethestrong(weak)ISOoverSAcorrespondstocyclonic(anticyclonic)atmosphericcirculationoverSCS,whileinJulyandAugusttheatmosphericcirculationisinthesamephaseregardlessofwhethertheISOoverSAisstrongorweak.Theimpactsofthestrong(weak)ISOoverSCSontherainfallofeasternChinaaresimilarinJuneandJuly,whichfavorsless(more)rainfallinYangtze-HuaiheRiversbasinbutsufficient(deficient)rainfallinthesouthofYangtzeRiver.However,theimpactsarenotsoapparentinAugust.InSouthAsia,thestrong(weak)ISOinJulyresultsinless(more)rainfallinthesouthofYangtzeRiverbutsufficient(deficient)rainfallinYangtze-HuaiheRiversbasin.TheinfluenceontherainfallineasternChinainJuneandAugustisnotassignificantasinJuly.
简介:TheexistingestimatesofthevolumetransportfromthePacificOceantotheSouthChinaSeaaresummarized,showinganannualmeanwestwardtransport,withtheTaiwanStraitoutflowsubtracted,of3.5±2.0Sv(1Sv=106m3s-1).Resultsofaglobaloceancirculationmodelshowanannualmeantransportof3.9SvfromthePacifictotheIndianOceanthroughtheSouthChinaSea.TheborealwintertransportislargerandexhibitsaSouthChinaSeabranchofthePacific-to-IndianOceanthroughflow,whichoriginatesfromthewesternPhilippineSeatowardtheIndonesianSeasthroughtheSouthChinaSea,aswellasthroughtheKarimataandMindoroStraits.ThesouthwestwardcurrentnearthecontinentalslopeofthenorthernSouthChinaSeaisshowntobeacombinationofthisbranchandtheinteriorcirculationgyre.Thiswinterbranchcanbeconfirmedbytrajectoriesofsatellite-trackeddrifters,whichclearlyshowaflowfromtheLuz6nStraittotheKarimataStraitinwinter.Insummer,theflowintheKarimataStraitisreversed.NumericalmodelresultsindicatethatthePacificwatercanentertheSouthChinaSeaandexittowardtheSuluSea,butnoobservationalevidenceisavailable.Therolesofthethroughflowbranchinthecirculation,waterpropertiesandair-seaexchangeoftheSouthChinaSea,andinenhancingandregulatingthevolumetransportandreducingtheheattransportoftheIndonesianThroughflow,arediscussed.
简介:DRAFTPROPOSALFORTHESOUTHCHINASEAMONSOONEXPERIMENT(SCSMEX)ChenLongxun(陈隆勋)DRAFTPROPOSALFORTHESOUTHCHINASEAMONSOONEXPERIMENT(SC...
简介:ThecomparisonanalysesbetweentwotropicaldepressionsintheSouthChinaSeaarecompletedbynumericalex-perimentswithalimitedareamodeldevelopedinGuangzhouInstituteofTropicalandOceanicMeteorology.Oneofthedepressionsdevelopsandfinallybecomesatyphoonwithin24hoursoftheanalyzingperiod(definedasDVDhereafter),andtheothernot(definedasUNDVD)Theanalysesshowthattheirinitialstructuresoftemperature,humidity,pres-sure.windandstabilityareobviouslydifferentfromeachother.Thereareaverydeepwetlayerandaclearwarm-coredstructureinthemid-lowertroposphereinthedepressionareaintheDVDcase,butwiththewarmcoreintheupperratherthanlowertropospherearidaveryshallowwetlayerinthelowertroposphereinthedepressionareaintheUNDVDcase.Thedevelopingandnon-developingprocessesaresuccessfullysimulatedbythemodel,showingthattheCISKmechanismplaysthemostimportantroleinthedevelopmentofSCSDs(TropicalDepressionsintheSouthChinaSea).SeveralnumericalexperimentsshowthatthestructuresofhumidityandtemperatureinthedepressionareahaveimportanteffectonthedevelopmentofSCSDs.ItisfavourabletothedevelopmentofSCSDswhenaverydeepwetlayerexistsinthemid-lowertroposphereorawarm-coredstructureexistsinthemid-lowertroposphereinsteadofinuppertroposphere,andconversely,itisunfavourabletothedevelopmentofSCSDswhenthewetlayerisveryshallowinthelowertroposphereorthewarm-coredstructureisintheuppertroposphereratherthaninmid-lowertroposphere.Thestructuresofstabilityforeachcasearealsoanalysed,whichshowsevidentdifferencesbetweenthetwocases,withadeeperinstabilitylayerintheDVDcaseandashalloweroneintheUNDVDcase.Finally,thesensitivityofthedevel-opmentoftheSCSDstotheverticalstructuresofhumidityandtemperatureinthedepressionareaisdiscussed.
简介:这研究调查了通过确定、概率的预报在华南在2007年4月23日与伪静止的前面联系的一根嚎啕线的可预测性。我们的结果证明嚎啕线模拟是很敏感的在物理parameterization计划从水平分辨率和无常为错误建模。至少一种10-km格子尺寸是必要的高雅地捕获这根嚎啕线。有4.5km的一种格子尺寸的模仿的嚎啕线对相对象微视物理学和行星的边界层那样的另外的物理计划的长波浪的放射parameterization计划很敏感。为从20~5km的一种格子尺寸,一个积云parameterization计划降级了嚎啕线模拟(相对关掉它),与到格子尺寸的更严重的降级<10km比>10km。到起始的错误的嚎啕线模拟的敏感通过整体预报被调查。嚎啕线的整体模拟的表演对起始的错误很敏感。约15%整体成员高雅地捕获了嚎啕线的进化,25%失败了,并且60%打乱了嚎啕线。用物理parameterization的不同联合,为不同成员的计划能改进概率的预报。这个案例的铅时间仅仅是一些小时。错误生长清楚地与潮湿的传送对流开发被联系。当起始的错误逐渐地被减少时,在嚎啕线模拟的性能的线性改进被观察,与来自起始的潮湿地的最大的贡献。
简介:ThecoastalareaofsouthernChinaisfrequentlyaffectedbymarinemeteorologicaldisasters,andisalsooneofthekeyareasthatinfluencetheshort-termclimatechangeofChina.Duetoalackofobservationalfacilitiesandtechniques,littlehasbeendoneinthisareaintermsofoperationalweathermonitoringandscientificresearchonatmosphericandmarineenvironment.WiththesupportofChinaMeteorologicalAdministration(CMA)andGuangdongMeteorologicalBureau(GMB),theMarineMeteorologicalScienceExperimentBase(MMSEB)atBohe,MaominghasbeenjointlyestablishedbyGuangzhouInstituteofTropicalandMarineMeteorology(GITMM)andMaomingMeteorologicalBureau(MMB)ofGuangdongProvinceafterthreeyearsofhardwork.Ithasbecomeanintegratedcoastalobservationbasethatisequippedwithacompletesetofsophisticatedinstruments.Equipmentmaintenanceanddataqualitycontrolprocedureshavebeenimplementedtoensurethelong-term,steadyoperationoftheinstrumentsandtheavailabilityofhighqualitydata.PreliminaryobservationsshowthatthedataobtainedbytheMMSEBrevealmanyinterestingfeaturesintheboundarylayerstructureandair-seainteractioninsuchdisastrousweatherastyphoonsandseafog.TheMMSEBisexpectedtoplayanimportantroleinthescientificresearchofdisastrousweatherrelatedtomarinemeteorology.
简介:Aheavyrainfallassociatedwiththedeepeningofamonsoondepressionhappenedinthesummerof2005.Thisprocesswasfirstdiagnosticallyanalyzedandthe3Dstructureofthemonsoondepressionwasdiscussed,thenthisstructurewascomparedwiththoseofthemonsoondepressioninSouthAsiaandthelowvortexintheMeiyufront.TheresultsshowedthattheheavyrainfalldirectlyresultedfromamonsoondepressioninSouthChina,andthelarge-scaleenvironmentprovidedafavorablebackgroundforthedeepeningofthemonsoondepression.The3Dstructureofthemonsoondepressionwasasfollows.Inthehorizontaldirection,thereexistedaconvectivecloudbandtothesouthofthemonsoondepression,whichlayinaconvectivelyinstablearea,witharelativelystrongascendingmotioninthemidandlowlevelsofthetroposphere,andtheascendingmotionmatchedwellwithamoisttongue,aconvergencearea,andabandofpositivevorticityinthemidandlowlevelsofthetroposphere.Intheverticaldirection,thedepressionhadanobviouslycycloniccirculationinthemidandlowlevelsofthetroposphere,butnocirculationfromabove300hPa.Themonsoondepressioncorrespondedtoconvergenceandpositivevorticityinthelowlevels,buttodivergenceandnegativevorticityintheupperlevels.Theupwarddraftofthedepressioncouldreachtheupperlevelsofthetroposphereinthewestofthedepression,whilethedescendingmotionlayintheeast.Therewasalow-leveljettothesouthofthedepression,whiletheupper-leveljetwasnotobvious.Thedepressionwasverticallywarmintheupperlevelsandcoldinthelowlevels,andtheaxisofthedepressiontiltedsoutheastwardwithheight,whosecharacteristicsweredifferentnotonlyfromthemonsoondepressioninSouthAsiabutalsofromthelowvortexintheMeiyufront.
简介:Basedonacurrentfogdetectiontheory,amultibandthresholdmethodforMODISdatawasputforwardtodetectdaytimefogintheSouthChinaSea.ItusedBands1,2,18,20and31ofMODISdatatoseparatefogfromthecloudandtheseasurface.Thedigitaldetectionindexeswereasfollows.IfRB1<20%,RB2<20%andRB1>RB2,thepixelwasidentifiedtobetheseasurface.IfRB1>55%,RB2>55%andTB31<273K,thepixelwasidentifiedtobeamiddle-andhigh-levelcloud.IfIFC>20,thepixelwasclassifiedtobeseafog.ThemethodwasverifiedwithseafogdataobservedfromthecoastalregionofGuangdongduringJanuary-April2011.Outofthe13samplesofsatellitedetection,ninewereconsistentwiththesurfaceobservations,threewereidentifiedtobelow-levelthecloudaccordingtothesatellitedetectionbutfogaccordingtothesurfaceobservations,andonlyonesamplewasidentifiedtobetheoceansurfacebythesatellitedetectionbutfogbythesurfaceobservations.BecausetheMODISdatacannotpenetratethecloudorfog,themodelwasdesignedforasinglefieldofviewwhichhadonlyonelayerofcloudorfog.Itcanaccuratelydistinguishfogwhichisnotcoveredbythecloud,butitidentifiesfogascloudiftheformeriscoveredbyacloud.Generallyspeaking,themodeliseffectiveandfeasible.
简介:GrowingevidenceindicatesthattheAsianmonsoonplaysanimportantroleinaffectingtheweatherandclimateoutsideofAsia.However,thisactiveroleofthemonsoonhasnotbeendemonstratedasthoroughlyashasthevariabilityofthemonsooncausedbyvariousimpactingfactorssuchasseasurfacetemperatureandlandsurface.ThisstudyinvestigatestherelationshipbetweentheAsianmonsoonandtheclimateanomaliesintheAsian-Pacific-American(APA)sector.Ahypothesisistestedthatthevariabilityoftheupper-troposphericSouthAsianhigh(SAH),whichiscloselyassociatedwiththeoverallheatingofthelarge-scaleAsianmonsoon,islinkedtochangesinthesubtropicalwesternPacifichigh(SWPH),themidPacifictrough,andtheMexicanhigh.ThechangesinthesecirculationsystemscausevariabilityinsurfacetemperatureandprecipitationintheAPAregion.AstrongerSAHisaccompaniedbyastrongerandmoreextensiveSWPH.TheenlargementoftheSWPHweakensthemid-Pacifictrough.Asaresult,thesouthernportionoftheMexicanhighbecomesstronger.Thesechangesareassociatedwithchangesinatmosphericteleconnections,precipitation,andsurfacetemperaturethroughouttheAPAregion.WhentheSAHisstronger,precipitationincreasesinsouthernAsia,decreasesoverthePacificOcean,andincreasesovertheCentralAmerica.PrecipitationalsoincreasesoverAustraliaandcentralAfricaanddecreasesintheMediterraneanregion.Whilethesignalsinsurfacetemperatureareweakoverthetropicallandportion,theyareapparentinthemidlatitudesandovertheeasternPacificOcean.
简介:用U.S.National,环境预言/公民的中心在1湯挠獡?桔?敲?瑬?桳睯摥琠慨?桴牥?獩愠挠楲楴慣?楤瑳湡散搠?潦?体噄?为大气的研究分析数据集中湩戠牡'覙H楮?瑡潭灳敨敲圮敨?桴?楤瑳湡散戠瑥敷湥猠灥牡瑡摥瘠牯楴散?獩猠慭汬牥琠慨?牯攠畱污琠?绥鳟彌B?潶瑲捩獥猠汥?牯慧楮敺椠Ь