简介：TwofieldexperimentswereperformedinordertodissipatethefogatWuqingDistrictofTianjininNovemberandDecemberof2009.Hygroscopicparticleswereseededtodissipatefogdropletson6-7November,2009.Liquidnitrogen(LN)wasseededintothenaturalsupercooledfogintheexperimentsof30November–1December,2009.Significantresponsewasfoundafterseeding.Significantchangeswereobservedinthemicrostructureoffoginthefieldexperiments.Theoffogdropletchangeddramatically;itincreasedfirstandthendecreasedafterseeding.RemarkablevariationalsowasfoundintheLiquidWaterContent(LWC)andinthesizeoffogdroplet.TheDropletSizeDistribution(DSD)offogbroadenedduringtheseedingexperiments.TheDSDbecamenarrowaftertheseedingended.Afterseeding,thedropletswerefoundtobeatdifferentstagesofgrowth,resultinginatransformofDSDbetweenunimodaldistributionandbimodaldistribution.TheDSDwasunimodalbeforeseedingandthenbimodalduringtheseedingexperiment.Finally,theDSDbecameunimodallydistributedonceagain.

简介：Inthispaper,twosnowfallcasesunderdifferentweatherconditionsinnorthernChinaaresimulatedbyusingthemesoscalemodelMM5.Two-waynestingstructureofdomainsisdesignedforeachcase.AmongtheexplicitschemesofMM5,theReisnergraupelschemeisselectedtodescribethemicrophysicalprocess.Thesimulatedsnow-bandsoftwocasesarebasicallyconsistentwithobservations.Thesimulatedresultsofmicrophysicalprocessesaremainlydiscussed.Thehydrometeorsandtheirsourcesandsinksunderdifferentweatherbackgroundsaredescribed.Thefeedbackeffectsofmicrophysicalprocessesonthethermalanddynamicprocessesarealsodiscussed.Methodthatoutputstheaccumulativesourcesandsinksperhourisusedtoanalyzethedistributioncharacteristicsofhydrometeorsduringthestrongestsnowfallperiod.Twosensitivitytests(calledheattestanddragtest)areconductedtoexaminetheeffectsofmicrophysicalpro-cessesoncloudproducedbythelatentheatanddragforce.Resultshaveshownthatthedistributionofparticleshasacloserelationwithtemperature.Thetem-peratureofBeijingsnowfallisunder0℃andthereexistvaporandsolidphaseparticles,whileLiaoningsnowfallhasvapor,liquid,andsolidphaseparticlesduetothewarmtemperature.Thedistributionoftheseparticlesisnotthesameatdifferentdevelopmentstages.Fromtheanalysesofthecharacteristicsofsourcesandsinks,itisfoundthatsnowismainlyproducedbythedepositionandaccretionwithice.Cloudwateriscrucialtograupel.Themeltingofice-phaseparticlesenhancestherainproduction.Theresultsofheattestsanddragtestsrevealthatthemicrophysicalprocesseshaveinteractedwiththedynamicandthermalprocesses.Latentheatreleaseofhydrometeorsfeedsbackpositivelyonsnowfallwhilethedragforcenot.Atlast,comparisonsofsimulatedresultshavebeendonebetweenthetwodifferentkindsofsnowfallcases.ThemicrophysicalprocessesofLiaoningsnowfallcaseismorecomplicatedthanthoseofBe

简介：根据Anderson亲爱原则，为极其重的降雨(缩短的同样极端的降雨/降水)的预报的一个方法基于中国气象学的管理(CMA)的T213全球整体预言系统(EPS)的整体预报数据被开发。在20072010期间使用T213预报降水数据并且在20012010的JuneAugust的观察降雨数据，累积分发功能(CDF)的特征观察，T213EPS预报降水被分析。因此，根据在模型之间的CDF的连续差别，气候和EPS预报，极端降水预报索引(EPFI)的一个数学模型被建立并且适用在17312011年7月期间在中国预报几个极端降雨事件的实验。结果证明EPFI利用了模型的尾巴信息气候的CDF和极端降雨的提供的令人喜悦的的预报。EPFI为预先发给极端降雨的早警告37天基于T213EPS是有用的。与预报铅时间的扩展，EPFI变得不太熟练。结果也证明模型气候CDF的合理性具有到EPFI的技巧的重要重要性。