简介：Aquantitativeschemeisputforwardinourworkofforecastingthestormrainfalloftyphoonsforspecificsites.Usingtheinitialparameters,weathersituationsandphysicalquantitiesaswellasnumericalweatherpredictionproducts,theschemeconstructsmultivariate,objectiveandsimilaritycriteriaforenvironmentalfactorsforthetimebetweenthecurrentandforthcomingmomentwithinthedomainofforecast.Throughdefininganon-linearsimilarityindex,thisworkpresentsacomprehensiveassessmentofthesimilaritybetweenhistoricalsamplesoftyphoonsandthosebeingforecastintermsofcontinuousdynamicstatesunderthemultivariatecriteriainordertoidentifysimilarsamples.Thehistoricalrainfallrecordsofthesimilarsamplesareusedtorunweightedsummarizationofthesimilarityindextodeterminesite-specificandquantitativeforecastsoffuturetyphoonrainfall.Samplesresemblingthetyphoonbeingforecastareselectedbydefininganon-linearsimilarityindexcomposedofmultiplecriteria.Trialtestshavedemonstratedthatthisschemehaspositivepredictionskill.

简介：Anoptimizationmethodisbasedtodesignasnowfallestimatemethodbyradarforoperationalsnowwarning,anderrorestimationisanalyzedthroughacaseofheavysnowonMarch4,2007.Threemodifiedschemesaredevelopedforerrorscausedbytemperaturechanges,snowflaketerminalvelocity,thedistancefromtheradarandcalculationmethods.Duetotheimprovements,thecorrelationcoefficientbetweentheestimatedsnowfallandtheobservationis0.66(exceedingthe99%confidencelevel),theaveragerelativeerrorisreducedto48.74%,andthemethodisabletoestimateweaksnowfallof0.3mm/handheavysnowfallabove5mm/h.Thecorrelationcoefficientis0.82betweentheestimatedsnowfallfromthestations50to100kmfromtheradarandtheobservation.Theimprovedeffectisweakwhentheinfluenceofthesnowflaketerminalvelocityisconsideredinthosethreeimprovementprograms,whichmayberelatedtotheuniformecho.Theradarestimateofsnow,whichisclassifiedbythedistancebetweenthesampleandtheradar,hasthemostobviouseffect:itcannotonlyincreasethedegreeofsimilarity,butalsoreducetheoverestimateandtheundervaluationoftheerrorcausedbythedistancebetweenthesampleandtheradar.Theimprovedalgorithmfurtherimprovestheaccuracyoftheestimate.Theaveragerelativeerrorsare31%and27%fortheheavysnowfallof1.6to2.5mm/handabove2.6mm/h,respectively,buttheradaroverestimatesthesnowfallunder1.5mm/handunderestimatesthesnowfallabove2.6mm/h.Radarechomaynotbesensitivetotheintensityofsnowfall,andtheconsistencyshownbytheerrorcanbeexploitedtoreviseandimprovetheestimationaccuracyofsnowforecastintheoperationalwork.

简介：AquantitativediagnosisiscarriedoutfortheupwardbranchofalocalmeridionalcirculationoversouthernChina(SC)duringtheabnormalsnowstormswithseverefreezingrainfrom10Januaryto3February2008.Thediagnosticstudyshowsthattheupwardbranchismainlyassociatedwiththezonaladvectionofwesterlymomentumandmeridionaltemperatureadvectioninsteadofthelatentheating(whichiscommonlythedominantfactorinmanyotherstormcases).Thecorrespondingweatheranalysesindicatethat(1)thezonaladvectionofwesterlymomentumrepresentstheeffectoftheupper-leveldivergenceontheanticyclone-shearsideintheentranceofa200hPawesterlyjetwithawestwarddeviationfromitsclimatologicallocationoversouthwesternJapan;(2)themeridionaltemperatureadvectionrepresentstheinteractionbetweenthemid-lowerlayer(850to400hPa)warmadvectionoverSC(aheadoftemperatureandpressuretroughswiththelattertroughdeeperthantheformerintheBayofBengal)andcoldadvectionovernorthChina(steeredbyanunderlyingflowat500hPa);(3)therelativelyweakvaportransport(comparedtothatofspring,summerandautumn)fromtheBayofBengalandtheSouthChinaSeatoSCandtheexistenceofatemperatureinversionlayerinthelowertroposphereoverSCdiminishtheeffectoflatentheating.Withthesignificantincreaseofvaportransportafter24January,theroleoflatentheatingisupgradedtobecomethethirdpositivecontributortotheupwardbranchoverSC.

简介：WiththeschemeofthevariationanalysisandKalmanfilter,theradardatawereadjustedbythereal-timeraingaugedata.Theaccuracyofarealrainfallcalculationwasimprovedandtheresultscanbebasicallyusedforfloodforecasting.ItisconcludedthattheschemeissuitableintheupperandmiddlereachesoftheHuaiheRiver.

简介：追踪作为多尺度知道的算法追踪雷达的新雷达回响回应由跨关联(MTREC)在这研究被开发在不同空间规模分析雷达回响的运动。雷达回响的运动，特别地与对流暴风雪联系了，在导致对流暴风雪的形成的气象学的系统之中由于复杂相互作用在各种各样的空间规模展出不同特征。为空回响区域，平常的关联技术生产零或运动向量的很小的大小。减轻这些限制，MTREC由关联(TREC)使用追踪的雷达回响有一个大盒子的技术驾驶风驾驶的系统的运动，和MTREC与一个小盒子使用TREC技术决定估计小规模的内部运动向量。最后，MTREC向量被综合获得系统的运动和小规模的内部运动。MTREC技术的性能与用案例研究的TREC技术相比：Wenzhou雷达和一个嚎啕线系统在2005年9月11日在2011年6月23日观察的Khanun台风由北京雷达检测了。结果证明那更空间地变光滑，连续向量领域能被MTREC技术产生，它在追踪全部雷达反射率模式导致改进。新多尺度的追踪计划被使用在量的降水nowcasting的表演上学习它的影响。在一1-h铅时间的重降水的地点和紧张与使用雷达和雨计量器的量的降水估计更一致。

简介：ThepurposeofthisstudyistoselectasuitableseawindretrievalmethodforFY-3B(MWRI).Basedonthetraditionalempiricalmodelofretrievingseasurfacewindspeed,andinthecaseofsmallsamplesizeofFY-3Bsatelliteloadregressionanalysis,thispaperanalyzesthechanneldifferencesbetweentheFY-3Bsatellitemicrowaveradiationimager(MWRI)andTMIonboardtheTRMM.Thepaperalsoanalyzestheinfluenceofthesedifferencesonthechannelintermsofreceivingtemperature,includingchannelfrequency,sensitivityandscalingprecision.Then,thelimitedrangeofnewmodelcoefficientregressionanalysisisdetermined(inwhichthechannelrangesettingsincludetheinformationandfeaturesofchanneldifferences),theregressionmethodsofthefinitefieldareproposed,andtheempiricalmodelofwindspeedretrievalapplicabletoMWRIisobtained,whichachievesrobustresults.ComparedtotheTAObuoydata,themeandeviationofthenewmodelis0.4m/s,andthestandarddeviationis1.2m/s.Inaddition,theschematicdiagramofthetropicalseasurfacewindspeedretrievalisprovided.

简介：Sometypicalsamplesareusedtoexplorethequantitativecorrelationwiththeirfeaturesbetweenaconvectivecloudanditsrainfallfield,withwhichtodeveloptwomorphologicalfunctionsforthecorrelationandbysinglingouttheirmostsuitablegroupsofparametersweproposeamodelforquantitativelyestimatingprecipitationinthecontexto{thein-advancerecognitionofmeso-αconvectivesystempropertiesanditsprecipitatingcenter.Fromthemodelfittingprecisionandforecastingaccuracywefindthatitisfeasibletoutilizegeostationarymeteorologicalsatellite(GMS)digitalizedimageryforestimatingshort-termrainfallinaquantitativemanner.Also,evidencesuggeststhatthemodelissupposedtoberestrictedinitsapplicabilityduetothefactthattheemployedsamplesarefromrathertypicalrainfalleventsthatarelarge-scale,slow-movingandhavewell-definedgenesisanddissipativestages.