简介：Duetoincreasedaerosolemissionsandunfavorableweatherconditions,severehazeeventshaveoccurredfrequentlyinChinainthelast10years.Inaddition,theinteractionbetweentheboundarylayerandtheaerosolradiativeeffectmaybeanotherimportantfactorinhazeformation.Tobetterunderstandtheeffectofthisinteraction,theaerosolradiativeeffectonaseverehazeepisodethattookplaceinDecember2013wasinvestigatedbyusingtwoWRFChemmodelsimulationswithdifferentaerosolconfigurations.Theresultsshowedthatthemaximalreductionofregionalaveragesurfaceshortwaveradiation,latentheat,andsensibleheatduringthiseventwere88,12,and37Wm~(–2),respectively.Theplanetaryboundarylayerheight,daytimetemperature,andwindspeeddroppedby276m,1°C,and0.33ms~(–1),respectively.Theventilationcoefficientdroppedby8%–24%forinthecentralandnorthwesternYangtzeRiverDelta(YRD).Theupperleveloftheatmospherewaswarmedandthelowerlevelwascooled,whichstabilizedthestratification.Inaword,thedispersionabilityoftheatmospherewasweakenedduetotheaerosolradiativefeedback.AdditionalresultsshowedthatthePM_(2.5)concentrationinthecentralandnorthwesternYRDincreasedby6–18μgm~(–3),whichislessthan15%oftheaveragePM_(2.5)concentrationduringtheseverelypollutedperiodinthisarea.TheverticalprofileshowedthatthePM_(2.5)andPM_(10)concentrationsincreasedbelow950hPa,withamaximumincreaseof7and8μgm~(–3),respectively.Concentrationsreducedbetween950and800hPa,however,withamaximumreductionof3.5and4.5μgm~(–3),respectively.Generally,theaerosolradiativeeffectaggravatedthelevelofpollution,buttheeffectwaslimited,andthishazeeventwasmainlycausedbythestagnantmeteorologicalconditions.Theinteractionbetweentheboundarylayerandtheaerosolradiativeeffectmayhavebeenlessimportantthanthelarge-scalestaticweatherconditionsfortheformation

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简介：TyphoonslandinginthecentralandnorthofFujianProvinceoftenseriouslyimpactZhejiangProvince.MuchattentionhasbeengiventoexceptionallytorrentialrainintheSouth/NorthYandangmountainousregionsinthesoutheastofZhejiangProvinceassociatedwithtyphoon-landing.TyphoonHaitang(2005)isatypicalcaseofsuchacategory,whichlandedinHuangqiTownofLianjiangCountyinFujianProvince,andmeanwhilegreatlyimpactedSoutheastZhejiang.AnumericalsimulationhasbeenperformedwiththePSU/NCARnon-hydrostaticmodelMM5V3tostudythetorrentialrainassociatedwithTyphoonHaitang.ThecomparisonofsimulatedandobservedrainfallsshowsthattheMM5V3wasabletowellsimulatenotonlytheintensitybutalsothelocationsofsevereheavyrainofTyphoonHaitang,especiallythelocationsofthesouth/northheavyraincenterareasintheSouth/NorthYandangmountainousregions.Meanwhile,thediagnosticanalysishasbeenalsocarriedoutforbetterunderstandingofthesevereheavyrainmechanismbyusingthemodeloutputdataofhighresolution.Thediagnosticanalysisindicatesthatthewestwardtiltoftheaxisofvorticityfromlowerlayertoupperlayeroverthesouthheavyraincenterareaandthecoupledstructureofconvergenceinthelowerlayeranddivergenceintheupperleveloverthenorthheavyraincenterarea,werebothpropitioustostrongerupwardmotioninthelayersbetweenthemidandupperatmosphere,andthesecondarycirculationinducedbytheverticalshearoftheambientwindsfurtherstrengthenedtheupwardmotionintheheavyrainareas.AfterHaitangpassedthroughTaiwanIslandintotheTaiwanStrait,thewatervaporeastofTaiwanIslandwascontinuouslytransferredbytyphooncirculationtowardsSouthWenzhou,leadingtothetorrentialrainfallintheSouthYandangmountainousregionsouthofWenzhou.Subsequently,Haitangmovednorthwards,thewatervaporbelteastofTaiwanIslandslowlyadvancednorthwards,theprecipitationrateobviouslyenhancedintheNorth

简介：BystatisticalresearchontheoccurrencepatternofsevereconvectiveweatherinJiangsuprovinceundertheinfluenceoftropicalcycloneswithina10-yearperiod(from2001to2010),thispaperdiscoversthatamongdifferentsevereconvectiveweather,theoccurrencefrequencyofshort-rangeheavyprecipitationisthehighest,thunderstormsandgalescomeinsecond,andgeneralthunderstormsrarelyhappen,whilehailstormsandtornadoesneveroccur.Thestatisticalresultsalsoshowedthatwithintheresearchperiodthereare21tropicalcyclones(TCs)affectingtheJiangsuareaandmostofthemareinthestageofweakeningtotropicaldepressions.Moreover,throughstudyingindicesforrelevantcasesofsevereconvection,itisdiscoveredthattheirthresholdsarelowerthanthatofpreviousresearch,whichindicatedthatconvectiveinstabilityandenergyaccumulationcaneasilyleadtosevereconvectiveweathereventuallyduetotheinfluenceofTCs.

简介：UsingsingleDopplerweatherradarechoinformation,thispaperpresentsatechniqueforrecognizingtwo-di-mensionalflowfieldstructureoftheseverestormandestimatingthedivergence,thevorticity,andtheintensityofwindshearline,andgivessomeexamples.

简介：从在诺思中国上的2010-14的严重天气报告和合成雷达反射率数据被用来分析严重的对流的风(SCW)的分发事件和他们雷达反射率的组织上的模式。为SCW事件的六个组织上的模式(并且他们的比例)簇房间(35.4%)，嚎啕线(18.4%)，非线性形状的系统(17.8%)，破线(11.6%)，单个房间(1.2%)，和弓回应(0.5%)。为嚎啕线和破线的山峰月是6月，而它是为另外的四个模式的7月。SCW事件的最高的数字在山上，它通常与簇房间的瓦解的系统被联系。相反，与线性系统联系的SCW主要在平原上发生了，在车站每年记录了不到一个SCW事件的一般水准的地方。有与非线性形状的系统联系的SCW的高频率的区域也经历了与嚎啕线联系的许多SCW事件。对流可得到的势能的价值，能使沉淀的水，0-3-km砍，并且0-6-km砍，比在山上在平原上是可论证地更大的，它在SCW事件的组织上的模式上有明显的效果。因此，地形学可以是在为在诺思中国上的SCW事件的组织上的模式的一个重要因素。

简介：ＡｎａｌｙｓｉｓｏｆＣａｕｓｅｓａｎｄＳｅａｓｏｎａｌＰｒｅｄｉｃｔｉｏｎｏｆｔｈｅＳｅｖｅｒｅＦｌｏｏｄｓｉｎＹａｎｇｔｚｅ／ＨｕａｉｈｅＢａｓｉｎｓｄｕｒｉｎｇＳｕｍｍｅｒ１９９１ＸｕＱｕｎ（徐群）（ＪｉａｎｇｓｕＭｅｔｅｏｒｏｌｏｇｉｃａｌｉｎ...

简介：WhensupertyphoonSepatcameclosetotheFujiancoastlineonthenightof18August2007(codedas0709inChineseconvention),anassociatedtornado-likeseverestormdevelopedat2307–2320BeijingStandardTimeinLonggang,CangnanCounty,WenzhouPrefecture,ZhejiangProvinceapproximately300kmawayintheforwarddirectionofthetyphoon.Thestormcausedheavylossesinlivesandproperty.Studyingthebackgroundoftheformationofthestorm,thispaperidentifiessomeofitstypicalcharacteristicsafteranalyzingitsretrievalofDopplerradardata,verticalwindshearandsoon.Synopticconditions,suchasunstableweatherprocessesandTBB,arealsostudied.

简介：垂直的风的效果砍，云microphysical预算上的放射，和冰云与奔流的降雨联系了在期间乍见陆地，严重热带暴风雨，Bilis(2006)被使用二天的格子规模敏感实验数据的一系列分析调查。当upper-tropospheric向上打手势，lower-tropospheric向下打手势时，发生在2006年7月15日，垂直的风的移动砍，从降雨的冰云增加降雨贡献打字(厘米)与积极的网冷凝作用和hydrometeor损失/集中联系了，而云的排除从厘米的放射的效果和云放射相互作用还原剂降雨贡献。垂直的风的消除砍并且从降雨类型(厘米)的云放射相互作用增加降雨贡献与积极的网冷凝作用和hydrometeor获得/分叉联系了，但是云的移动从厘米的放射的效果和冰云减少降雨贡献。在从与否定的网冷凝作用和hydrometeor损失/集中联系的降雨类型(厘米)的降雨贡献的改进被云的排除引起放射的效果，云放射相互作用和冰云，而在从厘米的降雨贡献的减小源于垂直的风的移动砍。当向上的运动在7月16日出现在整个对流层时，所有这些效果的排除从厘米增加降雨贡献，但是通常减少从厘米和厘米的降雨贡献。

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简介：Thetotal15severedroughtsarediscoveredwiththeaidofthe'RetrievalSystemofChineseHistoricalClimateRecords'forthelast1000years.Thedroughtsareextensivetoenvelopemorethan4provincesandpersistenttocover3yrormore,andtheirseverityisequivalenttoorinexcessofthatinthe1930sinChina.Accordingtothedocumentaryrecordsandrestorationsitcanbeinferredthatmostdroughtsaremoreseverethanthoseinthelast50years.The15droughtsmayeitheroccurwarmorinacoldclimatebackground,with11ofthe15casesinthecoldphase.ThisindicatesthedifferenceinclimatecorrespondencebetweenChinaandnorthernAmerica,showingtheseverityoftheeventsinChinatobeinacoldinsteadofawarmclimatesituation.ThatislikelytorelatetothemonsoonclimateineasternAsia.

简介：Theintraseasonaloscillation(ISO)isstudiedduringtheseverefloodanddroughtyearsoftheChangjiang-HuaiheRiverBasinwiththeNCEP/NCARreanalysisdataandtheprecipitationdatainChina.Theresultsshowthattheupper-level(200hPa)ISOpatternforsevereflood(drought)ischarac-terizedbyananticyclonic(cyclonic)circulationoverthesouthernTibetanPlateauandacyclonic(anti-cyclonic)circulationoverthenorthernTibetanPlateau.Thelower-level(850hPa)ISOpatternischar-acterizedbyananticyclonic(cyclonic)circulationovertheareasouthoftheChangjiangRiver,theSouthChinaSea,andtheWesternPacific,andacyclonic(anticyclonic)circulationfromtheareanorthoftheChangjiangRivertoJapan.Theselow-levelISOcirculationpatternsarethefirstmodesoftheISOwindfieldaccordingtothevectorEOFexpansionwithstrongeramplitudeoftheEOF1timecoefficientinse-verefloodyearsthaninseveredroughtyears.Theanalysesalsorevealthatat500hPaand200hPa,theatmosphericISOactivityovertheChangjiang-HuaiheRiverbasin,NorthChina,andthemiddle-highlatitudesnorthofChinaisstrongerforseverefloodthanforseveredrought.TheISOmeridionalwindoverthemiddle-highlatituderegionscanpropagatesouthwardsandmeetwiththenorthwardpropagatingISOmeridionalwindfromlowerlatituderegionsovertheChangjiang-HuaiheRiverBasinduringseverefloodyears,butnotduringseveredroughtyears.

简介：PossiblerelationshipsbetweenMJOandthesevererain-snowweatherinEasternChinaduringNovemberof2009areanalyzedandresultsshowthatastrongMJOprocessisoneofthestrongimpactfactors.MJOisveryactiveovertheIndianOceaninNovember2009.Especially,itmaintains9daysinMJOphase3,justcorrespondingtothetwostrongestrain-snowprocesses.CompositesofMJOeventsshowthatwhentheMJOconvectivecenterislocatedovertheIndianOcean,theprobabilityofrainfallissignificantlyincreasedandthetemperatureislowerthannormalineasternChina,whichisconsistentwiththesituationinNovemberof2009.Atmosphericcirculationanomaliesofmid-andhigher-latitudescanbeinfluencedbythetropicalMJOconvectionforcingandthisinfluencecouldberealizedbyteleconnection.WhentheMJOisovertheIndianOcean,itisfavorableforthemaintenanceofacirculationpatternoftworidgesversusonetroughatmid-andhigher-latitudes.Meanwhile,thewesternPacificsubtropicalhighisstrongerandmorewestwardthannormal,andasignificantconvectivebeltappearsovereasternEastAsia.AllthesecirculationanomaliesshowninthecompositeresultalsoappearedintheobservationsinNovember2009,whichindicatesthegeneralfeaturesofrelationshipsbetweentheMJOandthecirculationanomaliesovertheextratropics.Besidesthezonalcirculationanomalies,theMJOconvectioncanalsoleadtomeridionalcirculationanomalies.WhentheMJOconvectionislocatedovertheIndianOcean,thewesternPacificisdominatedbyanomalousdescendingmotion,andtheeasternEastAsiaiscontrolledbystrongconvergenceandascendingmotion.Therefore,ananomalousmeridionalcirculationisformedbetweenthetropicsandmiddlelatitudes,enhancingthenorthwardtransportationoflow-levelmoisture.Itispotentiallyhelpfultounderstandingandevenforecastingsuchkindofrain-snowweatheranomaliesasthatinNovember2009usingMJO.