简介：Therelationshipbetweenthetropicalintra-seasonaloscillation(ISO)andtropicalcyclones(TCs)activitiesovertheSouthChinaSea(SCS)isinvestigatedbyutilizingtheNationalCentersforEnvironmentalPrediction/NationalCenterforAtmosphericResearch(NCEP/NCAR)globalreanalysisdataandtropicalcyclonebest-trackdatafrom1949to2009.Themainconclusionsare:(1)AnewISOindexisdesignedtodescribethetropicalISOactivityovertheSCS,whichcansimplyexpressISOforSCS.AfterexaminingtheapplicabilityoftheindexconstructedbytheClimatePredictionCenter(CPC),wefindthattheconvectionspatialscalereflectedbythisindexistoolargetocharacterizethesmall-scaleSCSandfailstodividetheTCsactivitiesovertheSCSintoactiveandinactivecategories.Consequently,theCPCindexcan’treplacethefunctionofthenewISOindex;(2)TheeastwardspreadprocessoftropicalISOisdividedintoeightphasesusingthenewISOindex,thephasevariationofwhichcorrespondswellwiththeTCsactivitiesovertheSCS.TCsgenerationandlandingaresignificantlyreducedduringinactiveperiod(phase4-6)relativetothatduringactiveperiod(phase7-3);(3)ThecompositeanalysesindicatedistinctTCsactivitiesovertheSCS,whichisconsistentwiththeconcomitantpropagationoftheISOconvectiveactivity.DuringISOactiveperiod,theweathersituationsarefavorableforTCsdevelopmentovertheSCS,e.g.,strongconvection,cyclonicshearandweaksubtropicalhigh,andviceversa;(4)Thecondensationheatingcenters,strongconvectionandwatervaporfluxdivergencearewellcollocatedwitheachotherduringISOactiveperiod.Inaddition,theverticalprofileofcondensationheatindicatesstrongascendingmotionandmiddle-levelheatingovertheSCSduringactiveperiod,andviceversa.Thus,theeastwardpropagationoftropicalISOiscapabletomodulateTCsactivitiesbyaffectingtheheatingconfigurationovertheSCS.

简介：BasedonNCEP/CFSR0.5°reanalysisdataandthebesttrackdatafromtheJapanTokyoTyphoonCenter,compositeandcomparativeanalysesdemonstratetheasymmetricalstructuresofthetemperatureandhumidityintropicalcyclonesovertheWesternNorthPacificandtheSouthChinaSeafrom1979to2010.Theresultsareshownasfollows.（1）Withintensifyingtropicalcyclones,theflowfieldtendstobecomegraduallymoreaxisymmetric;however,theasymmetryofthespecifichumidityintheouterregionsismoreobvious.（2）Ingeneral,tropicalcycloneshaveanon-uniform,vertical,'doublewarm-core'structure.The'warm-cores'inthelowerlevelofweaktropicalcyclonesandinthehigherlevelofstrongtropicalcyclonesarethestrongerofthetwo.（3）Thedistributionareaofa'warm-core'isenhancedwithcycloneintensificationandtendstobecomemoreaxisymmetric.At200hPa,the'warm-core'ofaweakcyclonehasaweakanticycloneinthecenter,whereasthatofastrongcyclonehasaweakcycloneinthecenter.（4）The'wet-core'ofatropicalcycloneisprimarilylocatedinthelowerlevel（700-850hPa）.Withthecyclone’sintensification,theintensityofthe'wet-core'increasesandthescopeofthe0.8gkg-1specifichumidityanomalytendstoexpandtohigherlevels.（5）Withthecyclone’sdeepening,thepseudo-equivalentpotentialtemperatureatdifferentlevelsindifferentregionsincreases.Inaddition,thelargestwarmingratesateachintensitylevelinthedifferentregionsoccurinthecorearea,followedinturnbytheenvelopeandouterareas.

简介：以前的研究建议在北热带大西洋(NTA)上的春天SST异例影响热带气旋(TC)在在下列夏天和秋天的西方的诺思太平洋(WNP)上的活动。现在的学习表明在春天NTASST和后面的夏天秋天WNPTC开始频率之间的连接不是静止的。后面的夏天秋天WNPTC开始频率上的春天NTASST的影响是在前弱、不足道，却在以后强壮、重要，1980年代末。在1980年代末前，在热带中央太平洋的NTASST导致异例的SST异例是弱的，并且在WNP上的大气的循环的反应不是强壮的。作为结果，在春天NTASST和后面的夏天秋天WNPTC开始频率之间的连接在以前的时期是不足道的。在1980年代末以后，相反，NTASST异例通过大西洋和平的teleconnection导致显著热带中央和平的SST异例。热带中央和平的SST异例进一步为WNPTC开始导致有利条件，包括垂直运动，中间水平的相对湿度，和垂直的带的风砍。因此，在NTASST之间的连接和WNPTC开始频率在最近的时期是重要的。进一步的分析证明interdecadal在在春天NTASST之间的连接变化，后面的夏天秋天WNPTC开始频率可能与在NTA区域上的climatologicalSST变化有关。

简介：Theeffectsofverticalwindshearontropicalcyclone(TC)intensitychangeareexaminedbasedontheTCdatafromtheChinaMeteorologicalAdministrationandtheNCEPreanalysisdailydatafrom2001to2006.First,theinfluenceofwindshearbetweendifferentverticallevelsandaveragesindifferenthorizontalareasarecompared.Theresultsindicatethattheeffectofwindshearbetween200and850hPaaveragedwithina200-800kmannulusonTCintensitychangeislargerthananyothercalculatedverticalwindshear.High-latitudeandintenseTCstendtobelesssensitivetotheeffectsofVWSthanlow-latitudeandweakTCs.TCsexperiencetimelagsbetweentheimpositionoftheshearandtheweakeninginTCintensity.Averticalshearof8-9m/s(9-10m/s)wouldweakenTCintensitywithin60h(48h).Averticalsheargreaterthan10m/swouldweakenTCintensitywithin6h.Finally,astatisticalTCintensitypredictionschemeisdevelopedbyusingpartialleastsquaresregression,whichproducesskillfulintensityforecastswhenpotentialpredictorsincludefactorsrelatedtotheverticalwindshear.Analysisofthestandardizedregressioncoefficientsfurtherconfirmstheobtainedstatisticalresults.

简介：BasedontheJointTyphoonWarningCenter(JTWC)best-trackdatasetbetween1965and2009andthecharacteristicparametersincludingtropicalcyclone(TC)position,intensity,pathlengthanddirection,amethodforobjectiveclassificationoftheNorthwesternPacifictropicalcyclonetracksisestablishedbyusingk-meansClustering.TheTClifespan,energy,activeseasonandlandfallprobabilityofsevenclustersoftropicalcyclonetracksarecomparativelyanalyzed.Thecharacteristicsoftheseparametersarequitedifferentamongdifferenttropicalcyclonetrackclusters.Fromthetrendofthepasttwodecades,thefrequencyofthewesternrecurvingcluster(accountingfor21.3%ofthetotal)increased,andthelifespanelongatedslightly,whichdiffersfromtheotherclusters.TheannualvariationofthePowerDissipationIndex(PDI)ofmostclustersmainlydependedontheTCintensityandfrequency.However,theannualvariationofthePDIinthenorthwesternmovingthenrecurvingclusterandthepelagicwest-northwestmovingclustermainlydependedonthefrequency.

简介：UtilizingtheJointTyphoonWarningCenter(JTWC)andTokyo-TyphoonCenteroftheJapanMeteorologicalAgency(JMARSMCTOKYO)best-tracktropicalcyclone(TC)datafortheperiod1951-2014,variationsinspatialandtemporalcharacteristicsofNorthwestPacificTCactivityforaglobalwarmingscenarioarediscussed.Theresultssuggestthatsincetheearly1960s,therehasbeenanoveralldecreasingtrendinthefrequencyofoccurrence,intensity,peakintensity,lengthofmovement,andlifetimeofTCs.However,globalwanninghasledtoalinearlyincreasingtrendinTCactivityineasternAsia,whichindicatesthatNorthwestPacificTCactivitydecreases,butthefrequencyoflandfallsandintensityarelikelystrengthened.Therefore,thethreatofTCstowardseasternAsiaisenhanced.TheincreaseinTCactivityineasternAsiaislikelytheresultofastrengthenedWalkercirculationduetoanincreasingtemperaturegradientbetweenthenorthwestPacificOceanandthecentralandeasternPacificOcean.ThestrengtheningWalkercirculationcouldincreasethemagnitudeoftheverticalwindshear,relativevorticity,andmeridionalwindshearoflow-leveleasterliesneartheequatorinthetropicalNorthwestPacific,whichaffectsthespatialandtemporalvariationsofTCactivityintheNorthwestPacific.

简介：CombinedwithTRMMproductsandTropicalCyclone(TC)besttrackdatainNorthwestPacificfrom1January2003to31December2009,atotalof118TCs,including336instantaneousTCprecipitationobservationsareestablishedastheTRMMTCdatabase,andthedatabaseisstratifiedintofourintensityclassesaccordingtothestandardofTCintensityadoptedbyChinaMeteorologicalAdministration(CMA):SevereTropicalStorm(STS),Typhoon(TY),SevereTyphoon(STY)andSuperTyphoon(SuperTY).ForeachTCsnapshot,themeanrainfalldistributioniscomputedusing10-kmannulifromtheTCcentertoa300-kmradius,thentheaxisymmetriccomponentofTCrainfallisrepresentedbytheradialdistributionoftheazimuthalmeanrainrate;themeanrainrates,raintypesoccurrenceandcontributionproportionarecomputedforeachTCintensityclass;andthemeanquadrantaldistributionofrainratesalongTCsmotionisanalyzed.Theresultshowsthat:(1)TCsmeanrainratesincreasewiththeirintensityclasses,andtheirradialdistributionsshowsingle-peakcharacteristicgradually,andfurthermore,thecharacteristicsofrainratesoccurrenceandcontributionproportionchangefromdual-peaktosingle-peakdistribution,withthepeakrainrateatabout5.0mm/h;(2)Stratiformraindominatetheraintypeintheanalysiszone,whileconvectiverainmainlyoccurredintheeye-wallregion;(3)ThevaluesofmeanrainrateineachquadrantalongTCsmotionareclosetoeachother,relatively,thevalueintheright-rearquadrantisthesmallestone.

简介：Thisstudyfocusesonthedecadalvariabilityoftropicalcyclones(TC)overtheWesternNorthPacific(WNP)andhowthesechangesarerelatedtotheMadden-JulianOscillation(MJO).ItwasdonewiththehelpoftheReal-timeMultivariateMJOindexfromtheAustralianGovernmentBureauofMeteorologyoftheCentreforAustralianWeatherandClimateResearch,TCdatafromtheJointTyphoonWarmingCenterbesttrackdatasets,anddailyandmonthlydatasetsfromtheNCEP/NCARreanalysiscenter.TheresultsshowthattheTCfrequencyintheWNPexhibitedastatisticallysignificantdecreaseduring1998-2010comparedtoduring1979-1997.ThedecreaseinTCfrequencyintheWNPmainlyoccurredduringMJOactivephases(i.e.,phases4,5,6,and7).FurtherinvestigationoftheclimatebackgroundandthepropagationdifferencesoftheMJObetween1979-1997and1998-2010wasperformed.TheLaNina-liketropicalseasurfacetemperaturecoolingcausedstrongerWalkercirculationandthusinducedunfavorableatmosphereconditionsforWNPTCgenesisincludingalow-leveleasterlyanomaly,anegativerelativevorticityanomaly,anincreaseinsea-levelpressure,andstrongerverticalwindshear.Moreover,shorteningoftheMJOcycle,declineinthedurationoftheactivephasesintheWNP,andeasterlyanomalyandshrinkageoftheconvectionareaduringMJOactivephasesmayalsopartlyexplainthedecadalvariationofTC.

简介：到一架飞机上的起始的内部核心的结构的TC增强和轨道的敏感用一个数字模型被调查。结果证明有大内部核心的风(CVEX终止)的旋涡与小内部核心的风(CCAVE终止)比那经历更早的增强，但是他们将近在旋转起来以后有一样的增强率。在早阶段，与表面热流动联系的对流房间主要在CVEX终止在内部核心的区域以内被限制，而在CCAVE终止的旋涡与大多数由于效果在外部核心的区域被开始到东北的对流旋涡展出更加不对称的结构。在CVEX终止的大内部核心的惯性的稳定性能从到动能的对流加热在变换推动高效率。另外，在在主要eyewall外面的内部核心的区域的许多更强壮的拉紧变丑和PBL不平衡比在CCAVE终止，它在CVEX-EXP.对快速的axisymmetrization和早增强导致在CVEX终止的TC轨道在整个集成支撑向西北的排水量的在CVEX终止在起始的发展阶段期间续起，而当不对称的结构是主导的时，在CCAVE终止的TC经历向东北的反弯。由于到在CCAVE终止的TC中心的东北的提高的不对称的传送对流，一双第二等的旋回在大规模主要旋回形式以内嵌入，它调制通风流动并且因此驾驶TC移动向东北。

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.

简介：Thesecond-generationGlobalOceanDataAssimilationSystemoftheBeijingClimateCenter(BCC_GODAS2.0)hasbeenrundailyinapre-operationalmode.Itspanstheperiod1990tothepresentday.ThegoalofthispaperistointroducethemaincomponentsandtoevaluateBCC_GODAS2.0fortheusercommunity.BCC_GODAS2.0consistsofanobservationaldatapreprocess,oceandataqualitycontrolsystem,athree-dimensionalvariational(3DVAR)dataassimilation,andglobaloceancirculationmodel[ModularOceanModel4(MOM4)].MOM4isdrivenbysix-hourlyfluxesfromtheNationalCentersforEnvironmentalPrediction.Satellitealtimetrydata,SST,andin-situtemperatureandsalinitydataareassimilatedinrealtime.ThemonthlyresultsfromtheBCC_GODAS2.0reanalysisarecomparedandassessedwithobservationsfor1990-2011.TheclimatologyofthemixedlayerdepthofBCC-GODAS2.0isgenerallyinagreementwiththatofWorldOceanAtlas2001.ThemodeledsealevelvariationsinthetropicalPacificareconsistentwithobservationsfromsatellitealtimetryoninterannualtodecadaltimescales.PerformancesinpredictingvariationsintheSSTusingBCC_GODAS2.0areevaluated.ThestandarddeviationoftheSSTinBCC-GODAS2.0agreeswellwithobservationsinthetropicalPacific.BCC-GODAS2.0isabletocapturethemainfeaturesofE1NinoModokiIandModokiⅡ,whichhavedifferentimpactsonrainfallinsouthernChina.Inaddition,therelationshipsbetweentheIndianOceanandthetwotypesofE1NinoModokiarealsoreproduced.

简介：这份报纸调查与轨道预报了使用全球/地区性的吸收和预言系统(葡萄)的热带气旋(TC)联系的错误的可能的来源。葡萄预报在2008和2009个季节期间在西方的诺思太平洋盆为16landfallingTC被做，与72个小时的预报长度，并且使用缺省起始的条件(initials，此后)，它从NCEP-FNL数据集，以及ECMWFinitials。预报与ECMWF预报相比。当与缺省initials相比使用ECMWFinitials时，结果证明在大多数TC，GRAPES预报被改进。与ECMWFinitials相比，缺省initials生产更低的紧张TC和更低的紧张副热带的高度，而是更高的紧张南亚高度和季风马槽，以及更高的温度但是在TC中心的更低的特定的湿度。有ECMWFinitials在并且在在起始的时间的TC中心附近的geopotential高度和风地的代替被发现是改进预报的最有效的方法。另外，在预报精确性显示出最大的改进的TC通常在TC紧张有最大的起始的无常并且通常在加强的阶段。结果为用葡萄做的TC轨道预报表明起始的紧张的重要性，并且显示模型在比TC的腐烂的阶段描述加强的阶段更好。最后，改进的限制显示与葡萄预报联系的模型错误可以是landfallingTC的差的预报的主要原因。因此，模型错误的进一步的考试被要求。

简介：在空气的顶的放射预算在气候研究起一个关键作用。比作宽带流动，幽灵似地解决的出去的longwave放射或流动(OLR)，与在不同乐队的富有的大气的信息，在GCM的评估有明显的优点。不同于需要辅助大小和信息的方法，这里，我们拿大气红外线更健全(表情)观察作为一个例子当模特儿由尖分布造一个前後一致的算法(ADM)，完全基于发光观察，在热带海洋上估计清楚天空的幽灵似地解决的流动。作为为如此的ADM的关键步骤，景色类型评价在选择表情隧道从发光和亮度温度被获得。然后，宽带OLR象一样合成光谱流动被导出由光谱ADM并且使用合成系列和谷神星验证(云和地球绚烂的精力系统)观察。处于大多数状况，之间的吝啬的OLR差别光谱ADM产品和CERES观察在钫?以内??醰顣鱎???????？？

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.

简介：Toquantitativelystudytheroleoftropicalcycloneprecipitation(TCP)onalleviatingthedroughtinthesoutheastcoastalregionofChina(SCR)duringsummerandautumn,theobjectivesynopticanalysistechnique(OSAT),improvedforconsistencyandrationality,wasusedtoseparatetheTCPdataonthesummersandautumnsof1963-2005onthebasisofdailyprecipitationdatafromstationsandtropicalcyclonebesttrackdata.Afterdefiningtheseasondroughtindex,theactualdroughtdistributionandtheassumeddroughtdistributionwithoutTCPwereacquired.Theresultsshowedthatwithin1000kmfromthesoutheastcoastlineofChina,TCPaccountedfor11.3%ofnaturalprecipitation(NP).WithoutTCP,thedroughtindexintheSCRduringsummerwouldhaveincreasedfrom0.2to0.6orevenabove1.0insomeregionswhereasthedroughtindexduringautumnwouldhaveincreasedfrom0.4to0.6orabove1.2insomeregions.TheimpactofTCPondroughtdecreasesprogressivelyfromthesoutheastcoastlinetotheinlandregions.TheTCPproportion(TCPP)showedasignificantnegativecorrelationwiththedroughtindexinmanyregionsofthesoutheast,andthesignificantregioniswiderinautumnthaninsummer.TCPrelievedthedroughtmostsignificantlywithinarangeof0-500kmfromthesoutheastcoastline.Thisdroughtreliefshoweddifferentcharacteristicsfortheinterannualvariabilityinsummerandautumn,andthecrosswavelettransformindicatedthattheimpactofTCPondroughtmainlyliesin2-4-yeartimescales.Inparticular,therewasasignificanteffectduringthesummersof1977-1985andintheautumnsfollowingthatof1985.Therefore,TCPhasindeedlargelyalleviateddroughtintheSCRduringsummerandautumn.