简介:Aheavyrainfallassociatedwiththedeepeningofamonsoondepressionhappenedinthesummerof2005.Thisprocesswasfirstdiagnosticallyanalyzedandthe3Dstructureofthemonsoondepressionwasdiscussed,thenthisstructurewascomparedwiththoseofthemonsoondepressioninSouthAsiaandthelowvortexintheMeiyufront.TheresultsshowedthattheheavyrainfalldirectlyresultedfromamonsoondepressioninSouthChina,andthelarge-scaleenvironmentprovidedafavorablebackgroundforthedeepeningofthemonsoondepression.The3Dstructureofthemonsoondepressionwasasfollows.Inthehorizontaldirection,thereexistedaconvectivecloudbandtothesouthofthemonsoondepression,whichlayinaconvectivelyinstablearea,witharelativelystrongascendingmotioninthemidandlowlevelsofthetroposphere,andtheascendingmotionmatchedwellwithamoisttongue,aconvergencearea,andabandofpositivevorticityinthemidandlowlevelsofthetroposphere.Intheverticaldirection,thedepressionhadanobviouslycycloniccirculationinthemidandlowlevelsofthetroposphere,butnocirculationfromabove300hPa.Themonsoondepressioncorrespondedtoconvergenceandpositivevorticityinthelowlevels,buttodivergenceandnegativevorticityintheupperlevels.Theupwarddraftofthedepressioncouldreachtheupperlevelsofthetroposphereinthewestofthedepression,whilethedescendingmotionlayintheeast.Therewasalow-leveljettothesouthofthedepression,whiletheupper-leveljetwasnotobvious.Thedepressionwasverticallywarmintheupperlevelsandcoldinthelowlevels,andtheaxisofthedepressiontiltedsoutheastwardwithheight,whosecharacteristicsweredifferentnotonlyfromthemonsoondepressioninSouthAsiabutalsofromthelowvortexintheMeiyufront.
简介:Basedontheanalysesonamplitudesofhistoricalvariationoftemperatureandprecipitationinthepast500yearsandlatest100years,accordingtotheregionalclimatechangescenariosforChinaestimatedbycompositeGCM,thepotentialimpactsofclimatechangeoncroppingsystemsinChinainfuturearesimulatedandassessedusingthecroppingsystemmodeldevelopmentspeciallyfortheChinesecroppingpatterns.Itisshownthatundertheprojectedfutureclimatechangeby2050themostpartsofthepresentdoublecroppingareawouldbereplacedbythedifferenttriplecroppingpatternswhilethecurrentdoublecroppingareawouldshifttowardsthecentralpartofthepresentsinglecroppingarea.Moreexplicitly,thenorthernboundaryoftriplecroppingareawouldshiftfromitscurrentborderattheChangjingRivertotheHuangheRiver,ashiftofmorethan5degreesoflatitude.Andtheshiftofmultiplecroppingareasleadstoasignificantdecreaseofsinglecroppingarea.Furthermore,consideringthechangesmentionedaboveincombinationwiththelikelynegativebalanceofprecipitationandevapotranspirationand,therefore,increaseofmoisturestress(i.e.lesswateravailability),aswellasthepossibleincreaseofheatstressdisasteranddecreaseofLGS(lengthofgrowingseason),thepotentialimplicationofclimatechangeforagricultureinChinaarealsoanalyzedroughlyinthispaper.Asaresult,however,itisstillverydifficulttoreachaspecificconclusionthatthefutureclimatechangewillhefavorableorunfavorabletofarminChinabecauseofthecomplicatedChinesefarmingpatterns,thecomplex-varioussocialandeconomicenvironmentofagriculturaldevelopmentand,especially,agreatscientificuncertaintiesintheinvestigation/predictionofclimatechange.
简介:RecentadvancesinthestudyofnonlinearatmosphericandclimatedynamicsinChina(2003-2006)arebrieflyreviewed.Majorachievementsinthefollowingeightareasarecovered:nonlinearerrordynamicsandpredictability;nonlinearanalysisofobservationaldata;eddy-forcedenvelopeRossbysolitontheory;sensitivityandstabilityoftheocean'sthermohalinecirculation;nonlinearwavedynamics;nonlinearanal-ysisonfluctuationsintheatmosphericboundarylayer;thebasicstructuresofatmosphericmotions;someapplicationsofvariationalmethods.
简介:这研究在中国调查在夏天降雨之间的统计连接,使用欧亚的融雪水等价物(SWE)驻扎的从513的夏天降雨观察的数据集并且在在从1979~2004的时期期间的NCEP/NCAR分析的前面的春天,观察卫星的融雪水等价物,和大气循环变量。开始的二个联合模式被使用单个价值分解(SVD)识别方法。春天SWE可变性的领先的SVD模式在西藏的高原和东亚的一些小区域与相反的异例在大多数欧亚大陆显示出协调负异常。模式显示强壮内部年度可变性,迭加在上一内部发生在1980年代末的十的变化,与坚持的否定阶段在19791987并且经常的积极阶段以后。当领先的模式在它的积极阶段时,它在整个大多数欧亚大陆在春天对应于更少的SWE。同时,在西藏的高原和东亚,在南方的夏天降雨和东南中国的一些小区域的过多的SWE趋于被增加,而它将在黄河的起来到达被减少。在里面最近二十年,在欧亚大陆的减少的春天SWE可以在南方和东南中国是为在诺思和东北中国和更多重要降雨事件的严重干旱的原因之一。春天SWE可变性的第二个SVD模式在西方、东方的欧亚大陆出现在空间变化对面,当大多数西藏的高原和东亚在阶段时。这个模式显著地在诺思和东北中国与成功的夏天降雨相关,少些也就是说在东方欧亚大陆和西藏的高原在西方的欧亚大陆和过多的SWE触发SWE趋于在诺思和东北中国与减少的夏天降雨被联系。
简介:潮湿运输和在东北中国的普遍大雨和本地大雨事件的预算的特征从1961鈥?在东北中国用NCEP-NCAR分析6-hourly和每日的数据和200个车站的每日的降水数据被学习005。结果证明在有在东北中国的普遍大雨的时期期间,亚洲季风是很活跃的并且monsoonal向北方,潮湿运输显著地被加强。普遍重降雨从水蒸汽主要从亚洲季风区域发源的大区域获得提高的水蒸汽供应,它包括东方亚洲副热带的季风区域,华南海,和东南和西南热带季风区域。有在华东和它的沿海的区域上收敛的monsoonal潮湿电流的几个分支,在他们向北方被加强然后继续进东北中国的地方。因此,向北方提高了monsoonal潮湿运输是在东北中国的普遍大雨的关键。相反,在东北中国的本地重降雨从有限区域导出水蒸汽,由westerlies搬运了。本地蒸发也在水蒸汽供应和潮湿的本地再循环过程起一个重要作用。简言之,东北中国的普遍大雨主要走水路被引起亚洲季风带的蒸汽移流,而本地重降雨被西的风地的集中主要引起。
简介:TheregionalizationofclimateinChinaisbasedonathree-levelclassificationintermsoflastingdaysforaccumulatedtemperature(AT),aridityindex,andJulymeantemperature.Basedondailymeteorologicalobservationaldatafrom756stations,trendsandinterdecadalvariationinindicesforclassifyingtemperaturezones,moistureregionsandclimaticsubregionsintheperiod1961–2010arediscussed.ResultsrevealthatthenationwideAT10℃(AT10)anditslastingdaysarebasicallyincreasing,whilearidityinnorthernXinjiangisdecreasing.TheincreasingtrendofJulymeantemperatureinNorthChinaisfoundtobenotablylargerthaninSouthChina.Intermsoftheirnationalaverages,amarkedstepincreaseofAT10anditslastingperiod,aswellasJulymeantemperatureoccurredaround1997,whilethearidityindexpresentsnosuchclearchange.Bycomparingregionalizationareasfor1998–2010withthosefor1961–97,itisfoundthatthesemi-humid,semi-dryanddryregionsinthesub-temperatezone,aswellasthehumidregioninthemiddlesubtropicalzone,haveexperiencedsubstantialshrinkageintermsofarea.Incontrast,theareasofsemi-dryanddryregionsinthewarmtemperatezone,aswellasthehumidregioninthesouthsubtropicalzone,presentdrasticallyincreasingtrends.Owingtotheinfluenceofsuchstepchangesthattookplacein1997,thatparticularpointintimeshouldbegivencloseattentioninfuturestudiesregardingtheregionalizationofclimateinChina.
简介:自从2003,这篇论文考察中央规模天气动力学的主要理论进步,包括:(1)平衡并且失衡的流动的动态机制被使用学习中央规模循环的开始和发展问题。对称的不稳定性和横向波浪的不稳定性在线和旋涡空气传送对流被分析,并且进一步的研究在非线性的对流对称的不稳定性上被做了。在强迫对流和不稳定的传送对流和中央规模运动的波浪特征之间的相互作用也被讨论。(2)动态边界层建模的中间的空气被开发。复杂非线性的相互作用在大气的边界层和自由大气层之间理论上被分析。低级前面的地形学边界层和另外的边界层的结构动态问题被讨论。(3)在东亚空气发行量的背景下面的meso-β-scale暴风雨的形成和发展与MPV(潮湿的潜在的涡度)的变化被诊断异例。,并且在潮湿的空气。
简介:这篇论文在东北中国和它的连接上探讨冬季空气温度的interannual变化到前面的欧亚的雪盖子。结果证明在东北中国上在10月欧亚的雪盖子和后面冬季的空气温度之间有重要否定关联。位于东方西伯利亚并且到湖贝加尔湖的东北的雪盖子在冬季空气温度异例起一个重要作用。更多(更少)在10月的东方西伯利亚雪能引起气压是更高的一个大气的发行量异例在模式(更低)比在极的区域的正常并且更低(更高)在北中间高度的纬度。由于到下列冬季的从10月的东方西伯利亚雪的坚持,冬季大气的异例是有利的(相反)到寒冷的普遍运动,空气向北中间高度的纬度从极的区域集中并且因此,降低(更高)在东北中国上的温度。同时,当10月雪盖子是更多(更少)时,在西北的太平洋的SST连续地更低(更高)总体上;然后,低的阿留申群岛之土人和东亚马槽被增强(变弱),赞成更低(更高)在东北中国上的温度。
简介:Basedonacurrentfogdetectiontheory,amultibandthresholdmethodforMODISdatawasputforwardtodetectdaytimefogintheSouthChinaSea.ItusedBands1,2,18,20and31ofMODISdatatoseparatefogfromthecloudandtheseasurface.Thedigitaldetectionindexeswereasfollows.IfRB1<20%,RB2<20%andRB1>RB2,thepixelwasidentifiedtobetheseasurface.IfRB1>55%,RB2>55%andTB31<273K,thepixelwasidentifiedtobeamiddle-andhigh-levelcloud.IfIFC>20,thepixelwasclassifiedtobeseafog.ThemethodwasverifiedwithseafogdataobservedfromthecoastalregionofGuangdongduringJanuary-April2011.Outofthe13samplesofsatellitedetection,ninewereconsistentwiththesurfaceobservations,threewereidentifiedtobelow-levelthecloudaccordingtothesatellitedetectionbutfogaccordingtothesurfaceobservations,andonlyonesamplewasidentifiedtobetheoceansurfacebythesatellitedetectionbutfogbythesurfaceobservations.BecausetheMODISdatacannotpenetratethecloudorfog,themodelwasdesignedforasinglefieldofviewwhichhadonlyonelayerofcloudorfog.Itcanaccuratelydistinguishfogwhichisnotcoveredbythecloud,butitidentifiesfogascloudiftheformeriscoveredbyacloud.Generallyspeaking,themodeliseffectiveandfeasible.
简介:用先进研究WRF(ARWWRF)当模特儿并且Gridpoint统计插值(GSI)三维的变化分析(3DVAR)系统,吸收ATOVS的影响(先进初学者运作垂直更健全)通过原型社区放射的转移模型(pCRTM)的发光在预报在2005年6月20-21日在中国的东南发生在中央广东省上的重暴风雨上被评估。为这个盒子的一双比较实验(NODA和DA)与多重配置被进行,包括嵌套有4-km和12-km格子距离的领域。结果证明由通过数据吸收改变起始的条件,有偶极子的结构的一个修改分叉和潮湿领域与西南东北取向被加到雨线的轴。当一口西南的低级喷气(LLJ)带的更多的潮湿在Longmen的天文台车站附近被集成进雨线的东北部分时,,潮湿静电干扰精力(MSE)的振幅在中间的层次在底层实质地增加了,导致在在500hPa和850hPa之间的MSE扩大差别;空气变得更不稳定。因而,对流降雨在Longmen车站附近在省的东北部分增加了,它与降雨的观察分发一致。
简介:用U.S.National,环境预言/公民的中心在1湯挠獡?桔?敲?瑬?桳睯摥琠慨?桴牥?獩愠挠楲楴慣?楤瑳湡散搠?潦?体噄?为大气的研究分析数据集中湩戠牡'覙H楮?瑡潭灳敨敲圮敨?桴?楤瑳湡散戠瑥敷湥猠灥牡瑡摥瘠牯楴散?獩猠慭汬牥琠慨?牯攠畱污琠?绥鳟彌B?潶瑲捩獥猠汥?牯慧楮敺椠Ь
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
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简介:在广东省的自动气象站的格子数据,海军的研究实验室的卫星产品,常规气象学的数据和观察的NCEP全球数据吸收系统分析和环境条件被使用,大气的循环,并且在南部的中国诊断热带气旋Higos的增强的原因和机制的物理特征。结果显示出那高温度的有利环境条件,内在的表面的湿度,强壮的上面的分叉,弱垂直的风砍,并且在南部的Higos旁边的一条西南喷气溪流是的persistenceof贡献了紧张的themaintenance和Higos的重新增强的必要成分。从更低的对流层的冷空气的下沉侵入是为它在土地上的增强的批评条件。弱冷空气引起的正面的开始增加了更低的tropospheric集中并且直焰,并且潜伏的热由大雨释放了的冷凝作用支持了集中。从这个积极反馈过程,Higos获得了一增加积极涡度并且在土地上重新加强。重新增强对风和压力而且到它的温暖的核心的同时的热身运动的减小的逐渐增加到期不仅。
简介:Dailysnowdatafor2300climatestationscoveringtheperiodfrom1951through1980havebeenusedtomonitoranddiagnosesecularvariations,year-to-yearfluctuations,andthespatialcharacteristicsofsnowvariationtrendsinChina.AnexaminationoftimeseriesrevealsthatthereisastrongteleconnctiontoENSO,tomajorvolcaniceruptions,aswellastotheCO2-inducedwarming.Thecountry-widesnowmassvariationsarepositivelycorrelatedwithglobalmeantemperature,increasingduringthecurrentwarmingperiodanddecreasingduringtherecentcoolingperiodpriortothemid1960s.AsynchronousrelationshipexistsbetweenElNino/SouthernOscillationandsnowywinterinChina.Theyear-to-yearsnowfluctuationsseemtobegenerallyoutofphasewithvolcanicactivity.Theanomalymapshowsthatsnowmassincreasedinhighaltitudesandmoistregions,whileitdecreasedinaridlowlandandthesouthernbounda-ryzoneduringthewarmingperiod.ThepotentialCO2-inducedchangesinsnowmasswillfurtheraggravatetheregionaldifferentiationbetweenhighmountainsandlowlands,betweenmoistandaridregions.Thenumberofsnowcoverdayswilldecreaseinthenorthernlowlands,andsnowfallwillincreaseintheQinghai-XizangPlateau,highmountains,andthelowerreachesoftheChangjiang(Yangtze)River.
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:Aregionalclimatemodelisemployedtosimulatetheaerosols(dust,sulfate,blackcarbon,andorganiccarbon)andtheirdirecteffectontheclimateoverChina.Theemphasisisonthedirectradiativeforcingduetothechangeinmixingstateofaerosols.Theresultsshowthatdirectradiativeforcingissignificantlydifferentbetweenexternallyandinternallymixedaerosols.Atthetopoftheatmosphere(TOA),theradiativeforcingofexternallymixedaerosolsislargerthanthatofinternallymixedones,especiallyintheTarimdesertregionwherethedifferenceisabout0.7Wm2.Atthesurface,however,thesituationbecomesopposite,especiallyintheSichuanbasinwherethedifferenceisabout-1.4Wm2.Nonetheless,eitherexternallyorinternallymixedaerosolsinChinacanresultinasignificantcoolingeffect,exceptforthewarminginSouthChinainwinterandtheslightwarminginNorthChinainFebruary.Thecoolingeffectinducedbyexternallymixedaerosolsisweakerthanthatinducedbyinternallymixedaerosols,andthisismoreobviousinspringandwinterthaninsummerandautumn.Inspringandsummer,theinhibitingeffectofexternallymixedaerosolsonprecipitationislessthanthatofinternallymixedaerosols,whereasinautumnandwinterthedifferenceisnotobvious.
简介:在2015年9月8-9日发生在四川省上的一个地区性的重降水事件基于从气象站获得的时时观察的降水数据和NCEPFNL数据被分析。二个潮湿的动态参数,即,潮湿的涡度(m)和潮湿的分叉(m),被用来诊断这个重降水事件。结果证明在西南的中国上的地形学有这二个参数的能力上的重要影响诊断降水。当地形学的影响是弱的时(即,低高度),m不能确切在事件的起始的阶段描绘降水的地点。然后,当降水发展,它描绘地点的能力显著地改善。特别地,m在事件的山峰阶段期间与降水的地点与最好一致。而且,m中心的进化与降水中心的进化显示出高一致性。为m,尽管一些虚惊的区域是明显的,它几乎完全在降水事件期间反映降水的地点。然而,m中心与降水中心显示出矛盾。这些结果建议m和m有一个重要能力预言降水的地点。而且,m以预言降水中心的可变性比m有一个更强壮的能力。不管多么当地形学的影响是强壮的时(即,高高度),这两二个潮湿的动态参数是不能的在全部降水事件期间描绘降水的地点和中心,建议他们的弱能力在复杂地形学上预言降水。