简介：在这份报纸，在2005年7月9-10日期间发生在Huaihe河盆的重降雨进程被新一代学习数字天气预言模型系统--葡萄，从模型的预言上的不同起始的领域效果的看法。几个数字实验与起始的条件和T213L31和NCEP期末考试分析分别地提供的侧面的边界领域被进行。包括结果上的三维的变化吸收的效果，葡萄产生到不同起始的条件的预言产品的敏感被讨论。在分析二块起始的地和四模仿的结果之间的差别以后，到降水预报上的起始的地和他们的影响的模型的memonic能力被调查。分析证明亚synoptic的明显的差别在T213和NCEP起始的领域之间可伸缩，它导致相应不同模拟结果，并且差别不消失，集成跑。它是否有数据吸收，也为一样的起始的地显示出那，它仅仅显然影响葡萄模型结果在起始24h。然后，差别减少。另外，大雨的地点和紧张由葡萄预报模型进一步离事实，而是大奔流的雨的预报区域很亲密从事实有一些差别。当它有吸收，9-12-，12-24-，和0-24-h降水时，没有吸收，为一样的起始的地，模型的预报比那些好。都，这些建议葡萄数字预言的能力取决于不同的起始的地和侧面的边界条件到某程度，并且起始的地的差别将决定葡萄的差别模仿了结果。[出版摘要]

简介：Manystudieshaveexploredtheimportanceandinfluenceofplanetaryboundarylayerprocessesontropicalcyclones(TCs).However,fewstudieshavefocusedontheinfluenceoflandsurfaceprocessesontheactivityofTCs.TotesttheeffectofinitialperturbationsoflandsurfaceprocessesonTCs,alandsurfaceprocessperturbationmoduleisbuiltinaglobalensemblepredictionsystem.EnsembleexperimentsfortheTCsthatoccurredfrom12UTC22Augustto18UTC24November,2006showthatconsiderationoftheuncertaintieswithinthelandsurfaceprocesscouldincreasethepredictabilityoftheglobalensemblepredictionsystem.DetailedanalysisonTCXangsane(2006)indicatesthattheperturbationoflandsurfaceprocessesmayincreasethevariationofsensibleheatfluxandlatentheatflux.Meanwhile,theeffectfromlandsurfaceperturbationcanbetransferredtotheupperatmosphere,whichleadstobetterTCforecasts.

简介：Whethertheinitialconditionscontainpronouncedmesoscalesignalsisimportanttothesimulationofthesouthwestvortex.Aneastward-movingsouthwestvortexissimulatedusingthePSU/NCARMM5.Amodestdegreeofsuccessisachieved,butthemostseriousfailureisthattheformationanddisplacementofthesimulatedvortexinitsearlyphaseareaboutfourteenhourslaterthantheobservedvortex.Consideringtherelativelysparsedataonthemesoscalevortexandinanattempttounderstandthecauseoftheforecastfailure,anadjointmodelisusedtoexaminethesensitivityofthesouthwestvortextoperturbationsofinitialconditions.Theadjointsensitivityindicateshowsmallperturbationsofmodelvariablesattheinitialtimeinthemodeldomaincaninfluencethevortex.Alargesensitivityforzonalwindislocatedunder400hPa,alargesensitivityformeridionalwindislocatedunder500hPa,alargesensitivityfortemperatureislocatedbetween500and900hPa,andalmostallofthelargesensitivityareasarelocatedinthesouthwesternarea.Basedontheadjointsensitivityresults,perturbationsareaddedtoinitialconditionstoimprovethesimulationofthesouthwestvortex.Theresultsshowthattheinitialconditionswithperturbationscansuccessfullysimulatetheformationanddisplacementofthevortex;thewindperturbationsaddedtotheinitialconditionsappeartobeacyclonecirculationunderthemiddleleveloftheatmosphereinthesouthwesternareawithananticyclonecirculationtoitssouthwest;awatervaporperturbationaddedtoinitialconditionscanstrengthenthevortexandthespeedofitsdisplacement.

简介：Theformationofatropicalcycloneistheresultofaprocessinwhichaninitialdisturbanceevolvesintoawarm-corelow-pressuresystem;however,theoriginoftheinitialdisturbanceandthefeaturesoftheinitialfieldsareoverlookedinmostexistingtheories.Inthisstudy,basedonFY-2CbrightnesstemperaturedataandtheJapanreanalysisdataset,theoriginandevolutionofthetropicaldisturbancethatbecameTyphoonFung-Wong(2008)wereexamined.Theresultsdemonstratedthattheinitialdisturbanceemergedwithinasaddle-typefieldwithlargeverticaltroposphericwindshear.Theverticalwindsheardecreasedwiththeadjustmentoftheuppercirculation;moreover,accompaniedbyconvectionoverthewarmsectionaroundtheuppercoldvortex,itprovidedfavorablethermalanddynamicconditionsforthedevelopmentofatropicalvortex.Duringitsdevelopment,thezoneofassociatedpositiverelativevorticitystrengthenedanddescendedfromthemid-tropospheretolowerlevels.Thisrapidstrengtheningoflower-levelvorticitywasduetoincreasingconvergencerelatedtotheintensificationofthepressuregradientsouthwestofthesubtropicalhigh.ThisindicatedthattheuppercoldvortexandWestPacificsubtropicalhighplayedveryimportantrolesinthiscase.

简介：BasedontherealcaseofafrontalprecipitationprocessaffectingSouthChina,27controllednumericalexperimentswasmadefortheeffectsofhydrostaticandnon-hydrostaticeffects,differentdrivingmodels,combinationsofinitial/boundaryconditions,updatesoflateralvaluesandinitialtimelevelsofforecast,onmodelpredictions.Featuresabouttheimpactofinitial/boundaryconditionsonmesoscalenumericalweatherprediction(NWP)modelareanalyzedanddiscussedindetail.Sometheoreticallyandpracticallyvaluableconclusionsaredrawn.ItisfoundthattheoveralltendencyofmesoscaleNWPmodelsisgovernedbyitsdrivingmodel,withtheinitialconditionsshowingremarkableimpactsonmesoscalemodelsforthefirst10hoursofthepredictionswhileleavinglateralboundaryconditionstotakecaretheperiodbeyond;thelatteraffecttheinnerareaofmesoscalepredictionsmainlythroughthepropagationandmovementofweathersignals(waves)ofdifferenttimescales;initialvaluesofexternalmodelparameterssuchassoilmoisturecontentmayaffectpredictionsofmorelongertimevalidity,whilefastsignalsmaybefilteredawayandonlyinformationwithtimescale4timesaslargeasormorethantheupdatedperiodofboundaryvaluesmaybeintroduced,throughlateralboundary,tomesoscalemodels,etc.Someresultsmaybetakenasimportantguidanceonmesoscalemodelanditsdataassimilationdevelopmentsofthefuture.

简介：Mesoscaleensembleisanencouragingtechnologyforimprovingtheaccuracyofheavyrainfallpredictions.Occurrencesofheavyrainfallarecloselyrelatedtoconvectiveinstabilityandtopography.Inmid-latitudes,perturbedinitialfieldsformedium-rangeweatherforecastsareoftenconfiguredtofocusonthebaroclinicinstabilityratherthantheconvectiveinstability.Thus,alternativeapproachestogenerateinitialperturbationsneedtobedevelopedtoaccommodatetheuncertaintyoftheconvectiveinstability.Inthispaper,aninitialconditionperturbationapproachtomesoscaleheavyrainfallensembleprediction,namedasDifferentPhysicsModeMethod(DPMM),ispresentedindetail.BasedonthePSU/NCARmesoscalemodelMM5,anensemblepredictionexperimentonatypicalheavyrainfalleventinSouthChinaiscarriedoutbyusingtheDPMM,andthestructureoftheinitialconditionperturbationisanalyzed.Further,theDPMMensemblepredictioniscomparedwithamulti-physicsensembleprediction,andtheresultsshowthattheinitialperturbationfieldsfromtheDPMMhaveareasonablemesoscaiecirculationstructureandcouldreflectthepredictionuncertaintyinthesensitiveregionsofconvectiveinstability.AnevaluationoftheDPMMinitialconditionperturbationindicatesthattheDPMMmethodproducesbetterensemblemembersthanthemulti-physicsperturbationmethod,andcansignificantlyimprovetheprecipitationforecastthanthecontrolnon-ensemblerun.

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：TyphoonMegi,the13thtyphoonofthe2010typhoonseason,wasselectedforcasestudybyutilizingtheWeatherResearchandForecasting(WRF)model.Twelvesensitivityexperimentswithvariousinitialtropicalcyclone(TC)intensitiesandsizeswereconductedtoinvestigatetheirimpactsonthesimulationoftyphoontrack.InteractionbetweenTCandthewesternPacificsubtropicalhigh(WPSH)wasalsoanalyzedtoexplorethemechanismfortheimpactonTCtrackoftheinitialTCintensityandsize.NumericalresultsindicatethatthesimulatedTCsizeandTCtrackaresensitivetoinitialTCintensityandsize.StrongerinitialTCintensityandlargerinitialTCsizeoftenleadtolargersimulatedTCsizeandmakeTCturnnorthwardearlier.Furtheranalysissuggeststhat,withtheincreaseofinitialTCintensityandsize,moreairmassentersintotheTCregion,whichsubsequentlyreducestheextentofWPSH.Asaresult,thesteeringflowchangessignificantlyandeventuallycausestheTCtoturnnorthwardearlier.ThepresentstudyconfirmsthattheinitialTCintensityandsizehavecertaininfluencesontheTCtracksimulation,whichdemonstratestheimportanceofaccurateinitialconditionforsuccessfulsimulationoftheTCintensityandTCtrack.Moreover,italsodeepensourunderstandingoftheinteractionbetweenTCandWPSH,provideshelpfulcluesfortheTCtrackchangestudy,anddiscussesthefuturedirectionsforimprovementofTCtrackforecast.

简介：全球、地区性的吸收和预言系统(葡萄)，一个有限区域的地区性的模型，被用来在模拟预言模仿起始的域的相对不够的信息的华南海夏天monsoon.In看法的发作，从一颗NOAA卫星鸣Unit-B(AMSU-B)数据的先进微波被介绍用3-dimensional直接改进起始的values.By葡萄的变化数据吸收系统，为吸收测试的二个计划是des

简介：NumericalexperimentsofadjointvariationalassimilationhavebeenperformedusingtheknownLorenzsystem.Withtheincreaseofsensitivityofmodel’sinitialvalues,itismoreandmoredifficulttousetheadjointmethodtogettheinitialvalueswhichareconsistentwiththedynamicsofthefore-castmodel.Undersomecircumstancesthealgorithmcompletelyfails.Thisshowsthatfour-dimen-sionalassimilationisrelatedtothelimitofpredictability.Ontheotherhand.withtheincreaseofmodelequation’serror,theresultofvariationalassimilationmaybecomeworseandworsesothatthepredictionhasnomeaning.Butifthemodelparametersarecorrectedwhenvariationalassimilationismade,theforecastresultscanbegreatlyimprovedbasedonLorenzmodel.

简介：

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。