简介：BasedontheGlobalRegionalAssimilationandPredictionSystem-TropicalCycloneModel(GRAPES-TCM),anensembleforecastexperimentwasperformed,inwhichTyphoonWiphaduringtheperiodimmediatelypriortolandfallwasselectedforthestudyandthebreedingofgrowingmode(BGM)methodwasusedtoperturbtheinitialconditionsofthevortexfieldandtheenvironmentfield.TheresultsoftheexperimentindicatethateachmemberhadadifferentinitialstatusinBGMprocessingandtheyshowareasonablespreadamongmembersalongwiththeforecastphase.Changesinthelarge-scalefield,thermodynamicstructure,andspreadamongmemberstookplacewhenWiphamadelandfall.Thesteeringeffectofthelarge-scalefieldandtheinteractionbetweenthethermodynamicsandthedynamicsresultedindifferenttracksofthemembers.Meanwhile,theforecastuncertaintyincreased.Insummary,theensemblemeandidnotperformaswellasthecontrolforecast,buttheclustermeanprovidedsomeusefulinformation,andperformedbetterthanthecontrolinsomeinstances.Thepositionerrorwas34kmfor24hforecast,153kmfor48hforecast,and191kmfor66hforecast.Thestrikeprobabilitychartqualitativelydescribedtheforecastuncertainty.

简介：TheensemblebasedforecastsensitivitytoobservationmethodbyLiuandKalnayisappliedtotheSPEEDY-LETKFsystemtoestimatetheobservationimpactofthreetypesofsimulatedobservations.Theestimationresultsshowthatalltypesofobservationshavepositiveimpactonshort-rangeforecast.ThelargestimpactinNorthernHemisphereisproducedbyrawinsondes,followedbysatelliteretrievedprofilesandclouddriftwinddata,whichinSouthernHemisphereisproducedbysatelliteretrievedprofiles,rawinsondesandclouddriftwinddata.SatelliteretrievedprofilesinfluencemoreontheSouthernHemispherethanontheNorthernHemisphereduetofewobservationsfromrawinsondesintheSouthernHemisphere.Atthelevelof200to300hPa,thelargestimpactisattributedtowindobservationsfromrawinsondesandclouddriftwind.

简介：整体变换(et)方法被显示了在为适应观察推广提供指导有用。它在整体subspace用它的相应转变矩阵为各可能的推广预言预报错误变化减小。在这份报纸，一个新基于et的敏感(et)方法，以分析错误变化减小计算预报错误变化减小的坡度，被建议为可能的适应观察指定区域。et是ET的第一顺序近似；它要求就一个转变矩阵的一计算，增加计算效率(在计算费用的60%80%减小)。ETS坡度的明确的数学明确的表达被导出并且描述。ET和et方法为比较被用于飓风艾琳(2011)箱子和一个重降雨箱子。数字结果暗示ETS和et估计的敏感区域是类似的。然而，et是更有效的，特别地当分辨率更高，整体成员的数字更大时。

简介：作为预报问题的数据吸收和整体的一条统一途径，整体Kalman过滤器(EnKF)被用来暴风雨整体预报在232007年5月30日期间在东亚指向一个灰尘事件调查灰尘的性能。输入风地，灰尘排放紧张，和干燥免职速度里的错误在重要模型不确定性之中并且在模型错误不安被考虑。这些模型错误没被假定有零工具。代表模型偏爱的模型错误工具作为数据吸收进程的部分被估计。从一个激光雷达网络的观察被吸收产生起始的整体并且改正模型偏爱。整体预报技巧与观察和一张基准/控制预报被作比较，没有任何观察的吸收，它是简单模型跑。没有模型偏爱修正，另一个整体预报实验也被执行以便检验偏爱修正的影响。结果证明整体平均数，确定的预报在控制上有实质的改进预报并且正确地捕获在每个观察地点预定的主要灰尘到达和停止。然而，当预报铅时间增加，预报技巧减少。偏爱修正进一步改进了预报在在风区域下面。在24个小时以内的预报最被改进并且比那些好没有偏爱修正。用操作典型曲线和区域的荆棘分数和亲戚的整体预报技巧的考试显示预报系统的整体有有用预报技巧。

简介：

简介：一个新方法，使不安的BDA，在整体预报台风路经被使用。这个方法基于假数据吸收计划。它使不安台风的起始的位置和紧张并且得到一系列假旋涡。然后，每个假旋涡在数据吸收被使用获得初始条件。整体预报成员被与这些初始条件进行模拟构造。台风的一些盒子被选择测试这个新方法的有效性，结果显示出那：用使不安的BDA使不安的方法为轨道预报的台风的起始的位置和紧张能改进精确性，与BDA吸收计划的直接使用相比。并且如果，紧张of5hPa的一个使不安的振幅可能比10hPa更适当，这被结束使不安的BDA方法与起始的位置不安在联合被使用。

简介：在在多重线性回归(MLR)之间的季节的降水预报技巧的差别的调查整体并且简单多，模型整体平均数(他们)基于单个模型的预报质量。在以前的研究的差别的可能的原因被分析。以便做学习区域的模拟能力相对一致，有不同时间的关联系数的三个区域为这研究被选择。结果证明导致MLR途径的无能力的原因在不同区域之中变化。在Niño3.4区域，在单个模型以内的强壮的合作线性通常是主要原因。在高纬度区域，然而，没有重要合作线性能在单身的模型的单个模型，而是能力被发现是那么差的它在这个区域为超级整体预报使MLR来临不恰当。另外，当我们比较源于的结果时，注意各种各样的分数大小的使用能导致一些差异是重要的不同多为整体途径建模。

简介：等级直方图是合适的工具在一个整体预言系统或框架以内估计整体的质量。由在整体数一个给定的变量的等级，如果它的可变性的起源是外部噪音或来自混乱来源，我们基本上正在做样品分析，它不允许我们区分。最近介绍的平均数到变化对数(MVL)图说明空间可变性，对空间本地化很敏感由空间与时间的混乱系统的无穷小的不安生产了。由把一个简单模型题目用作一个基准到噪音，我们显示出等级直方图和MVL图给的不同信息。因此，外部噪音的主要效果能在一张图被设想。从MVL图，我们清楚地观察振幅生长率并且空间本地化(混乱抑制)的减小，当从等级直方图我们在整体的可靠性观察变化时。我们断定在包括空间与时间的混乱和噪音的一个复杂框架，两个提供一幅更完全的预报图画。

简介：这研究检验与一个整体Kalman过滤器(EnKF)联合确定的四维的变化吸收系统(4DVAR)为数据吸收生产一条优异混合途径的性能。当在阻止过滤器分叉利用4DVAR时，从使用州依赖者的不确定性的联合吸收计划(E4DVAR)好处由EnKF提供了：4DVAR分析通过费用的最小化生产以后的最大的可能性答案整体不安关于被转变的功能，和产生整体分析能为下一个吸收周期并且作为整体预报的一个基础向前被宣传。这条联合途径的可行性和有效性与模仿的观察在一个理想化的模型被表明。E4DVAR能够在完美模型、有瑕疵模型的情形下面超过4DVAR和EnKF，这被发现。联合计划的性能比为标准EnKF或4DVAR实现的那些对整体尺寸或吸收窗口长度也不太敏感。

简介：TheGRAPES-TCMisusedtomakeensemblepredictionexperimentsfortyphoontrack.Threekindsofensembleschemesaredesignedfortheexperiments.Atotalof109experimentsaremadefortheninetyphoonsin2011andtheintegraltimeis72h.Theexperimentresultsareshownasfollows.Inthethreeensembleschemes,onthewhole,scheme1hasthebesttrackprediction.Itsaverageabsolutetrackerrorandoveralldeviationsoftyphoonmovingspeedandmovingdirectionareallthesmallestinthethreeschemes.Forbothscheme1andscheme2,theyareallsmallerthanthoseoftheircontrolpredictions.Bothoftheirensemblepredictionsshowsuperioritytotheirdeterministicpredictions.Overall,comparedwiththeobservations,thetyphoonmovingdirectionsofthethreeschemesmainlyskewtotheright,andinthelateintegrationtheymainlytendtoberelativelyslow.Inthethreeschemes,thetrackdispersionofscheme1isthelargestandthatofscheme3thesmallest.Inscheme1itismuchlargerthaninschemes2and3.Thedifferenceofdispersionbetweenscheme2andscheme3issmall.Thetrackdispersionsofthethreeschemesareallmuchsmallerthantheirrationaldispersions.Comparedwiththeeightdomesticandoverseasoperationalnumericalweatherprediction(NWP)models,scheme1hasbetterpredictionsthantheothersevenoperationalmodelsexceptECMWFNWPmodel.Scheme1hasthevalueofoperationalapplication.

简介：BasedontheB08RDP(Beijing2008OlympicGamesMesoscaleEnsemblePredictionResearchandDevelopmentProject)thatwaslaunchedbytheWorldWeatherResearchProgramme(WWRP)in2004,aregionalensemblepredictionsystem(REPS)ata15-kmhorizontalresolutionwasdevelopedattheNationalMeteorologicalCenter(NMC)oftheChinaMeteorologicalAdministration(CMA).Supplementingtotheforecasters’subjectiveaffirmationonthepromisingperformanceoftheREPSduringthe2008BeijingOlympicGames(BOG),thispaperfocusesontheobjectiveverificationoftheREPSforprecipitationforecastsduringtheBOGperiod.Byuseofasetofadvancedprobabilisticverificationscores,thevalueoftheREPScomparedtothequasi-operationalglobalensemblepredictionsystem(GEPS)isassessedfora36-dayperiod(21July-24August2008).TheevaluationhereinvolvesdifferentaspectsoftheREPSandGEPS,includingtheirgeneralforecastskills,specificattributes(reliabilityandresolution),andrelatedeconomicvalues.TheresultsindicatethattheREPSgenerallyperformssignificantlybetterfortheshort-rangeprecipitationforecaststhantheGEPS,andforlighttoheavyrainfallevents,theREPSprovidesmoreskillfulforecastsforaccumulated6-and24-hprecipitation.ByfurtheridentifyingtheperformanceoftheREPSthroughtheattribute-focusedmeasures,itisfoundthattheadvantagesoftheREPSovertheGEPScomefrombetterreliability(smallerbiasesandbetterdispersion)andincreasedresolution.Also,evaluationofadecision-makingscorerevealsthatamuchlargergroupofusersbenefitsfromusingtheREPSforecaststhanusingthesinglemodel(thecontrolrun)forecasts,especiallyfortheheavyrainfallevents.

简介：在西方的太平洋上发生在2004-2006之间的八热带气旋的轨道的整体预言实验被与五积云parameterizationschemes使用MM5执行了。结果证明热带气旋的轨道的预言对积云parameterization计划的选择敏感。每个计划有它的自己的优点和劣势，并且没有积云parameterization计划的断言不是最糟，有时平比其它好。并且所有显著地三个整体方法改进轨道的预言，在哪个之中没有parameterization计划，Grell，Betts厂主和Kain-Fritsch计划的整体方法是最好。

简介：Ensembleforecastingoftropicalcyclone(TC)motionwasstudiedusingaprimitiveequationbarotropicmodelbyperturbinginitialpositionandstructurefor1979-1993TC.TheresultsshowthatTCinitialpositionperturbationaffectsitstrack,buttheensemblemeanisclosetocontrolforecast.ExperimentswasalsoperformedbyperturbingTCinitialparameterswhichwereusedtogenerateTCinitialfield,andmoreimprovementcanbeobtainedbytakingensemblemeanofselectivememberthanselectingmembersrandomly.Theskillof60%-70%ofallcasesisimprovedinselectiveensemblemean.Whentheambientsteeringcurrentisweak,moreimprovementcanbeobtainedoverthecontrolforecast.

简介：作者作为为整体由使用barotropic预报提供起始的不安的一个工具使用有条件的非线性的最佳的不安(CNOP)的技术伪因地球自转而引起(QG)在一种完美模型的情形当模特儿。为中等范围(14天)的整体预报由起始的状态制造由CNOP和单个向量(SV)使不安。当分析错误是一种快成长错误时，13个不同盒子被选择了。我们的实验证明CNOP的介绍比SV方法提供更好的预报技巧。而且，传播技巧关系表明第一SV被CNOP在代替的整体样品比SV从到白天14的白天6获得的那些显得优异。等级图被采用把新方法与SV途径作比较。结果说明CNOP的介绍为中等范围的整体预报有更高的可靠性。

简介：Byusinganine-levelatmosphericgeneralcirculationmodeldevelopedattheInstituteofAtmosphericPhysics(IAP9LAGCM),twosetsofnumericalexperimentsarecarriedouttoinvestigatetheinfluenceoftheMascarenehigh(MH)andAustralianhigh(AH)overthesouthernsubtropicsupontheEastAsiansummermonsooncirculationandsummerprecipitationinEastAsia.Theuseofensemblestatisticsisadoptedtoreducethesimulationerrors.TheresultshowsthatwiththeintensificationofMH,theSomalilow-leveljetissignificantlyenhancedtogetherwiththesummermonsooncirculationinthetropicalAsiaandwesternPacificregion.Furthermore,theanticyclonicanomalyinthetropicalwesternPacifictotheeastofthePhilippinesmayinduceaweakEast-Asia-Pacificteleconnectionpattern.Inthemeantime,geopotentialheightintheTropicsisenhancedwhileitisreducedovermostregionsofmid-highlatitudes,thusthenorthwesternPacificsubtropicalhighat500hPaextendssouthwestward,resultinginmorerainfallinsouthernChinaandlessrainfallinnorthernChina.AsimilaranomalypatternoftheatmosphericcirculationsystemsisfoundintheexperimentoftheintensificationofAH.Ontheotherhand,becausethecross-equatorialcurrentsassociatedwithAHaremuchweakerthantheSomalijet,theanomalymagnitudecausedbytiheintensificationofAHisgenerallyweak,andtheinfluenceofAHonsummerrainfallinChinaseemstobelocalizedinsouthernChina.ComparisonbetweenthetwosetsofexperimentsindicatesthatMHplaysacrucialroleintheinteractionsofgeneralatmosphericcirculationbetweenthetwohemispheres.

简介：为系统建模的Cloud-Aerosol-Radiation(汽车)整体最近被造了更好理解云/喷雾器/放射过程并且决定云/喷雾器/放射的不同处理在气候模型引起的无常。汽车系统包括云，喷雾器，和在文学可得到的放射进程的一个大计划集合，包括通常由带GCM的世界使用的那些。在这研究，详细说明了全面精确性的分析，CAR系统的效率被执行。尽管有使用的不同观察，CAR整体工具的全面精确性被发现对短波(SW)和longwave(LW)很好放射计算。与ISCCP(国际卫星云气候学工程)相比为2004年7月拿百分比错误数据在上(60tent和分析o吗？？

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：IntheEnsembleKalmanFilter(EnKF)dataassimilation-predictionsystem,mostofthecomputationtimeisspentonthepredictionrunsofensemblemembers.Alimitedorsmallensemblesizedoesreducethecomputationalcost,butanexcessivelysmallensemblesizeusuallyleadstofilterdivergence,especiallywhentherearemodelerrors.InordertoimprovetheefficiencyoftheEnKFdataassimilation-predictionsystemandpreventitagainstfilterdivergence,atime-expandedsamplingapproachforEnKFbasedontheWRF(WeatherResearchandForecasting)modelisusedtoassimilatesimulatedsoundingdata.TheapproachsamplesaseriesofperturbedstatevectorsfromNbmemberpredictionrunsnotonlyattheanalysistime(astheconventionalapproachdoes)butalsoatequallyseparatedtimelevels(timeintervalis△t)beforeandaftertheanalysistimewithMtimes.Alltheabovesampledstatevectorsareusedtoconstructtheensembleandcomputethebackgroundcovariancefortheanalysis,sotheensemblesizeisincreasedfromNbtoNb+2M×Nb=(1+2M)×Nb)withoutincreasingthenumberofpredictionruns(itisstillNb).Thisreducesthecomputationalcost.Aseriesofexperimentsareconductedtoinvestigatetheimpactof△t(thetimeintervaloftime-expandedsampling)andM(themaximumsamplingtimes)ontheanalysis.TheresultsshowthatiftandMareproperlyselected,thetime-expandedsamplingapproachachievesthesimilareffecttothatfromtheconventionalapproachwithanensemblesizeof(1+2M)×Nb,butthenumberofpredictionrunsisgreatlyreduced.

简介：InthispaperweinvestigatetheimpactoftheAtmosphericInfra-RedSounder(AIRS)temperatureretrievalsondataassimilationandtheresultingforecastsusingthefour-dimensionalLocalEnsembleTransformKalmanFilter(LETKF)dataassimilationschemeandareducedresolutionversionoftheNCEPGlobalForecastSystem(GFS).OurresultsindicatethattheAIRStemperatureretrievalshaveasignificantandconsistentpositiveimpactintheSouthernHemisphericextratropicsonbothanalysesandforecasts,whichisfoundnotonlyinthetemperaturefieldbutalsoinothervariables.IntropicsandtheNorthernHemisphericextratropicstheseimpactsaresmaller,butarestillgenerallypositiveorneutral.

简介：Thepaperinvestigatestheabilitytoretrievethetruesoilmoistureprofilebyassimilatingnear-surfacesoilmoistureintoasoilmoisturemodelwithanensembleKalmanfilter(EnKF)assimilationscheme,includingtheeffectofensemblesize,updateintervalandnonlinearitiesintheprofileretrieval,therequiredtimeforfullretrievalofthesoilmoistureprofiles,andthepossibleinfluenceofthedepthofthesoilmoistureobservation.Thesequestionsareaddressedbyadesktopstudyusingsyntheticdata.The'true'soilmoistureprofilesaregeneratedfromthesoilmoisturemodelundertheboundaryconditionof0.5cmd-1evaporation.Totesttheassimilationschemes,themodelisinitializedwithapoorinitialguessofthesoilmoistureprofile,anddifferentensemblesizesaretestedshowingthatanensembleof40membersisenoughtorepresentthecovarianceofthemodelforecasts.Alsocomparedaretheresultswiththosefromthedirectinsertionassimilationscheme,showingthattheEnKFissuperiortothedirectinsertionassimilationscheme,forhourlyobservations,withretrievalofthesoilmoistureprofilebeingachievedin16hascomparedto12daysormore.Fordailyobservations,thetruesoilmoistureprofileisachievedinabout15dayswiththeEnKF,butitisimpossibletoapproximatethetruemoisturewithin18daysbyusingdirectinsertion.ItisalsofoundthatobservationdepthdoesnothaveasignificanteffectonprofileretrievaltimefortheEnKF.Thenonlinearitieshavesomenegativeinfluenceontheoptimalestimatesofsoilmoistureprofilebutnotveryseriously.