学科分类
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27 个结果
  • 简介:85-stationdailyprecipitationdatafrom1961-2010providedbytheNationalMeteorologicalInformationCenterandtheNCEP/NCAR2010dailyreanalysisdataareusedtoinvestigatethelow-frequencyvariabilityontheprecipitationofthefirstrainseasonanditsrelationshipswithmoisturetransportinSouthChina,andchannelsoflow-frequencywatervaportransportandsourcesoflow-frequencyprecipitationarerevealed.Theannuallyfirstrainingseasonprecipitationin2010ismainlycontrolledby10-20dand30-60doscillation.Therainfallismore(interrupted)whenthetwolow-frequencycomponentsareinthesamepeak(valley)phase,andtherainfallislesswhentheyaresuperposedintheinversephase.The10-20dlow-frequencycomponentofthemoisturetransportismoreactivethanthe30-60d.The10-20dwatervaporsourceslieintheSouthIndiaOceannear30°S,theareabetweenSumatraandKalimantanIsland(thesouthwestsource),andtheequatorialmiddlePacificregion(thesoutheastsource),andtherearecorrespondingsouthwestandsoutheastmoisturetransportchannels.Byusingthecharacteristicsof10-20dwatervaportransportanomalouscirculation,thecorrespondinglow-frequencyprecipitationcanbepredicted6dahead.

  • 标签: LOW-FREQUENCY precipitation characteristics wavelet analysis LOW-FREQUENCY
  • 简介:ENERGETICDIAGNOSISFORTWOKINDSOFLOWLEVELJETSWangZhongxing(汪钟兴)(矫梅燕)(1.DepartmentofEarthandSpaceSciences,UniversityofScienceand...

  • 标签: low-level JET HEAVY RAIN ENERGETIC DIAGNOSIS
  • 简介:在大气的低频率的波浪上的海洋的强迫的效果(LFW为短)在海洋和空气分别地作为一个独立系统被拿的地方,在热带被分析。在这里,海洋的效果作为蒸发风反馈是parameterized(EWF为短)并且SST强迫。在EWF的调整下面,没有EWF,从那SST戏强迫一个不同角色因此LFW是diabatic飘动,由多重因素的相互作用强迫了,在热带。关键词大气的LFW-海洋的强迫-EWF-放射的冷却-SST这份报纸被鈥?首先支持海洋的科学,州的海洋的管理,地球物理的液体动力学的国家重点实验室和数字建模鈥的研究所?

  • 标签: ATMOSPHERIC LFW OCEANIC FORCING EWF RADIATIVE
  • 简介:在在灰尘天气的半球和它的可能的角色的低频率摆动在2002在诺思中国上袭击事件作为案例研究被分析。结果证明阿留申群岛之土人Low在3060天的摆动上在南半球与环极涡旋被连接,与趋于加深可能对尘暴事件的产生有用的阿留申群岛之土人Low的弱环极涡旋。在这后面的可能的机制是吝啬的经向环流的内部半球的相互作用,与在东亚上的主要可变性。在在上面的水平对流层的南半球的高纬度的带的吝啬的偏午可以带北半球的,它然后在北半球影响地方性环流。因此,低频率摆动电视连接是在在诺思中国上在南半球发行量和灰尘事件之间联合的一个可能的连接。然而,内部低频率摆动的年变化是不清楚的。

  • 标签: 低频振荡 2002年 中国北部 沙尘暴 大气环流
  • 简介:动态、数字的方法被用来热强迫讨论大气的反应到SST。结果表演为行星的规模系统,热强迫能快速激动的站的SST稳定的大气的平衡状态回答,它被明显的大规模电视连接摆动在东方西方和南方北方方向描绘。为摘要的规模系统,SST热强迫主要使大气的低频率的摆动激动。在SST之间的某基本关系和动态过程热强迫和大气的反应模式被揭示,一些新观点被介绍。

  • 标签: SST FIELDS thermal FORCING OSCILLATION LOW-FREQUENCY
  • 简介:TheArcticsea-iceextenthasshownadecliningtrendoverthepast30years.Icecoveragereachedhistoricminimain2007andagainin2012.Thistrendhasrecentlybeenassessedtobeuniqueoveratleastthelast1450years.Inthesummerof2010,averylowsea-iceconcentration(SIC)appearedathighArcticlatitudes--evenlowerthanthatofsurroundingpackiceatlowerlatitudes.Thisstrikinglowiceconcentration--referredtohereasarecordlowiceconcentrationinthecentralArctic(CARLIC)--isuniqueinouranalysisperiodof2003-15,andhasnotbeenpreviouslyreportedintheliterature.TheCARLICwasnottheresultoficemelt,becauseseaicewasstillquitethickbasedonin-situicethicknessmeasurements.Instead,divergenticedriftappearstohavebeenresponsiblefortheCARLIC.AhighcorrelationbetweenSICandwindstresscurlsuggeststhattheseaicedriftduringthesummerof2010respondedstronglytotheregionalwindforcing.ThedrifttrajectoriesoficebuoysexhibitedatranspolardriftintheAtlanticsectorandaneastwarddriftinthePacificsector,whichappearedtobenefittheCARLICin2010.Undertheseconditions,moresolarenergycanpenetrateintotheopenwater,increasingmeltthroughincreasedheatfluxtotheocean.Wespeculatethatthisdivergenceofseaicecouldoccurmoreofteninthecomingdecades,andimpactonhemisphericSICandfeedbacktotheclimate.

  • 标签: sea ICE concentration CENTRAL Arctic Beaufort
  • 简介:Haze-to-fogtransformationduringalonglasting,lowvisibilityepisodewasexaminedusingtheobservationsfromacomprehensivefieldcampaignconductedinNanjing,Chinaduring4-9December2013.Inthisepisode,hazewastransformedintofogandthefoglastedfordozensofhours.Theimpactsofmeteorologicalfactorssuchaswind,temperature(T)andrelativehumidity(RH)onhaze,transitionandfogduringthisepisodewereinvestigated.Resultsrevealedsignificantdifferencesbetweenhazeandfogdays,duetotheirdifferentformationmechanisms.Comparisonwasmadeforboundary-layerconditionsduringhazydays,haze-to-fogdaysandfoggydays.DistributionsofwindspeedandwinddirectionaswellassynopticweatherconditionsaroundNanjinghaddeterminativeimpactsontheoccurrencesandcharacteristicsofhazeandfog.WeakenedsoutherlywindinsouthernNanjingresultedinhighconcentrationofpollutants,andhazeeventsoccurredfrequentlyduringthestudyperiod.Thewindspeedwaslessthan1ms-1inthehazeevent,whichresultedinastableatmosphericconditionandweakdispersionofthepollutants.Theheightofthetemperatureinversionwasabout400mduringtheperiod.Theinversionintensitywasweakandthetemperature-differencewas4℃km-1orlessinhaze,whiletheinversionwasstronger,andtemperature-differencewasabout6℃km-1,approachingtheinversionlayerintensityinthefogevent.HazeeventisstronglyinfluencedbyambientRH.RHvaluesincreased,whichresultedinhazedaysevidentlyincreased,suggestingthatanincreasingfractionofhazeeventsbecausedbyhygroscopicgrowthofaerosols,ratherthansimplybyhighaerosolloading.WhenRHwasabove90%,hazeaerosolsstartedtobetransformedfromhazetofog.Thisstudycallsformoreeffortstocontrolemissionstopreventhazeeventsintheregion.

  • 标签: HAZE FOG TRANSFORMATION METEOROLOGICAL elements
  • 简介:DISTRIBUTIONOFLOWFREQUENCYWAVESINNORTHPACIFICANDINTRASEASONALABNORMALITYOFTHEWESTERNPACIFICSUBTROPICALHIGHLiXingliang(李兴亮)(Me...

  • 标签: LOW FREQUENCY wave SUBTROPICAL high ABNORMALITY
  • 简介:EarlystudiessuggestedthattheAleutian-Icelandiclowseesaw(AIS)featuresmultidecadalvariation.Inthisstudy,themultidecadalmodulationoftheAISandassociatedsurfaceclimatebytheAtlanticMultidecadalOscillation(AMO)duringlatewinter(February-March)isexploredwithobservationaldata.Itisshownthat,inthecoldphaseoftheAMO(AMOI-),aclearAISisestablished,whilethisisnotthecaseinthewarmphaseoftheAMO(AMO[+).ThesurfaceclimateoverEurasiaissignificantlyinfluencedbytheAMO'smodulationoftheAleutianlow(AL).Forexample,theweakALinAMOI-displayswarmersurfacetemperaturesovertheentireFarEastandalongtheRussianArcticcoastandintoNorthernEurope,butonlyovertheRussianFarEastinAMO{+.Similarly,precipitationdecreasesovercentralEuropewiththeweakALinAMOI-,butdecreasesovernorthernEuropeandincreasesoversouthernEuropeinAMOI+.

  • 标签: Aleutian-Icelandic LOW seesaw ATLANTIC Multidecadal Oscillation
  • 简介:Inthispaper,anerrorsourceintheatmosphericcomponentoftheCZ(Cane-Zebiak)modelisdiscussed,whichismissingafreemodein“theexactsolutions”.However,theimprovedschemeisproposed,whichisthecomputationalschemewithadjustedwindorobserveduandvaslateralboundaries.Thesimulationsshowthatthesimulatedsurfacewindbytheimprovedschemestrong-lybearsresemblancetotheobservationexceptfortheareanearthewestandtheeastboundariesoftheintegratedarea.Theseresultssupporttheconclusionthatthewindstresssimulatedbytheim-provedschemewithlateralboundariesismuchbetterthanthatsimulatedbytheCZmodel,andshowthatinteractionbetweenlowandmiddlelatitudeshasanimportantinfluenceontheENSOvariabilityintheCZmodel.Therefore,consideringitsimpactontheCZmodelcanimprovecapa-bilityoftheCZmodelforsimulatingENSOvariability.

  • 标签: INTERACTION ENSO VARIABILITY error source ATMOSPHERIC
  • 简介:ATibetanozonelowwasfoundinthe1990saftertheAntarcticozonehole.Whetherthisozonelowhasbeenrecoveringfromthebeginningofthe2000sfollowingtheglobalozonerecoveryisanintriguingtopic.WiththemostrecentmergedTOMS/SBUV(TotalOzoneMappingSpectrometer/SolarBackscatterUltraViolet)ozonedata,theTibetanozonelowanditslong-termvariationduring1979-2010areanalyzedusingastatisticalregressionmodelthatincludestheseasonalcycle,solarcycle,quasi-biennialoscillation(QBO),ENSOsignal,andtrends.TheresultsshowthattheTibetanozonelowmaintainsandmaybecomemoresevereonaverageduring1979-2010,comparedwithitsmeanstateintheperiodsbefore2000,possiblycausedbythestrongerdownwardtrendoftotalozoneconcentrationovertheTibet.Comparedwiththeozonevariationoverthenon-Tibetanregionalongthesamelatitudes,theTibetanozonehasalargerdownwardtrendduring1979-2010,withamaximumvalueof-0.40±0.10DUyr1inJanuary,whichsuggeststhestrengtheningoftheTibetanozonelowincontrasttotherecoveryofglobalozone.RegressionanalysesshowthattheQBOsignalplaysanimportantroleindeterminingthetotalozonevariationovertheTibet.Inaddition,thelong-termozonevariationovertheTibetanregionislargelyaffectedbythethermal-dynamicalproxiessuchasthelowerstratospherictemperature,withitscontributionreachingaround10%ofthetotalozonechange,whichisgreatlydifferentfromthatoverthenon-Tibetanregion.

  • 标签: 南极臭氧洞 西藏 长期变化 统计回归模型 藏族地区 臭氧总量
  • 简介:Basedonthedailymeantemperatureand24-haccumulatedtotalprecipitationovercentralandsouthernChina,thefeaturesandthepossiblecausesoftheextremeweathereventswithlowtemperatureandicingconditions,whichoccurredinthesouthernpartofChinaduringearly2008,areinvestigatedinthisstudy.Inaddition,multimodelconsensusforecastingexperimentsareconductedbyusingtheensembleforecastsofECMWF,JMA,NCEPandCMAtakenfromtheTIGGEarchives.ResultsshowthatmorethanathirdofthestationsinthesouthernpartofChinawerecoveredbytheextremelyabundantprecipitationwitha50-areturnperiod,andextremelylowtemperaturewitha50-areturnperiodoccurredintheGuizhouandwesternHunanprovinceaswell.Forthe24-to216-hsurfacetemperatureforecasts,thebias-removedmultimodelensemblemeanwithrunningtrainingperiod(R-BREM)hasthehighestforecastskillofallindividualmodelsandmultimodelconsensustechniques.TakingtheRMSEsoftheECMWF96-hforecastsasthecriterion,theforecasttimeofthesurfacetemperaturemaybeprolongedto192hoverthesoutheasterncoastofChinabyusingtheR-BREMtechnique.ForthesprinkleforecastsovercentralandsouthernChina,theR-BREMtechniquehasthebestperformanceintermsofthreatscores(TS)forthe24-to192-hforecastsexceptforthe72-hforecastsamongallindividualmodelsandmultimodelconsensustechniques.Forthemoderaterain,theforecastskilloftheR-BREMtechniqueissuperiortothoseofindividualmodelsandmultimodelensemblemean.

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  • 简介:Inthispaper,five-yearsimulateddatafromalow-resolutionglobalspectralmodelwithtriangulartrunca-lionatwavenumber10areanalyzedinordertostudydynamicalfeaturesandpropagationcharacteristicsofintraseasonaloxillationsoverthemid-latitudesandthetropicalatmosphere.Thesimulationsshowthatthereisthe30-50dayperiodicoscillationinthelow-resolutionspectralmodelwithoutnon-seasonalexternalforcing,andspatialscaleoftheintraseasonaloscihationsisoftheglobe.Furtheranalysisfindsthatpropagationcharac-tersofintraseasonaloscillationsoverthemid-latitudesandthetropicsaredifferent.The30-50dayoscillationoverthetropicsexhibitsstructureofthevelocitypotentialwavewithwavenumber1inthelatitudinalandthecharacterofthetravelingwaveeastwardatspeedof8longitudes/day.However,the30-50dayoscillationsinmid-latitudeatmosphereexhibitphaseandamplitudeoscillationofthestandingplanetarywavesandtheyarerelatedtotransformofteleconnectionpatternsoverthemid-latitudes.Theenergyisnotonlytransferredbetweenthetropicsandthemiddle-highlatitudes,butalsobetweendifferentregionsoverthetropics.Basedontheanalysisof5-yearbandpassfiltereddatafroma5-layerglobalspectralmodelofJow-ordetwithtruncatedwavenumberl0,investigationisdoneofthesourceofintraseasonaloscillationsintheextratropicalmodelatmosphereanditsmechanism.Resultsshowthat(1)theconvectiveheattransferredeastwardalongtheequatorservesasthesourceoftheintraseasonaloxillationbothinthetropicalandtheextratropicalatmos--phere;(2)thevelocity-potentialwaveofazonalstructureofwavenumber1givesrisetooxillationindivergentandconvergentwindfieldsofadipole-formasseenfromtheequatorialIndianOceantothewesternPacificduringitseastwardpropagation,thusindicatingtheoscillationinthedipole-formheatsoure:e/sinkpattertl;(3)thetropicalheat-sourceoscillationisresponsibleforthe

  • 标签: :intraseasonal OSCILLATION teleconnectionnormal MODE GLOBAL spe
  • 简介:中等范围的天气的欧洲中心从微波手足更健全的、高分辨率动力学手足预报重新分析过渡期间(时代过渡期间)气象学和大小更健全,并且在观察系统气味卫星的地球上监视仪器的臭氧被使用分析截止的动态、化学的特征低(关口)在在七月初2007的东北中国上的事件。结果在100300hPa显示出上层的温暖核心的气旋的极的同温层的起源,与塑造漏斗的对流顶层侵入进联系了就在COL中心上面中间对流层。列臭氧和臭氧侧面上的同温层的侵入的影响用卫星大小被调查。当COL的紧张在2007年7月10日达到顶点时,全部的列臭氧(TCO)增加到达了最大值(4070杜)。这能动态地被归因于两个对流顶层(75%)的降下并且向下越过对流顶层(25%)同温层的臭氧搬运。tropospheric臭氧侧面的分析在关口中心前在上层的前面区域附近越过对流顶层为充满臭氧的同温层的空气的不可逆的搬运/混合提供了证据。这臭氧侵入由上面的tropospheric风经历了下游的运输,导致由在从向经由南朝鲜的北日本海的华东延长的宽广区域上的1216杜的TCO的另外的增加。气象学的分析也在中间和更低的对流层在气旋的发展前显示出同温层的侵入的领先。

  • 标签: 中国东北地区 卫星观测 化学特性 对流层顶 数值天气预报 地球观测系统
  • 简介:Byusingthedatasetoflightraindaysandlowcloudcoverat51stationsinSouthChina(SC),andthemethodoflinearregressionandcorrelativeanalysis,weanalyzethespatiotemporalcharacteristicsofthelightraindaysandlowcloudcoverincludingannualvariationandlong-termseasonalchange.Theresultsareasfollows:(1)ThetrendsoflightraindaysandlowcloudcoveroverSCareopposite(lightraindaystendedtodecreaseandlowcloudcovertendedtoincreaseinthepast46years).Thevaluedistributedineastishigherthanthatinwest,andcoastalareahigherthaninlandarea.(2)Theregressioncoefficientsoflightraindaysandlowcloudcoverduring1960-2005are4.88d/10yearsand1.14%/10yearsrespectively,whichhadallpassedthe0.001significancelevel.(3)Variationsoflightraindaysarerelativelysmallinspringandsummer,buttheircontributionsarelargerforannualvaluethanthatofautumnandwinter.(4)Therearetworegionswithlargevaluesofaerosolopticaldepth(AOD),whichdistributeincentralandsouthernGuangxiandPearlRiverDelta(PRD)ofGuangdong,andthevalueofAODinPRDisupto0.7.Theaerosolindexdistributedincoastalareaishigherthanintheinlandarea,whichissimilartothelightraindaysandlowcloudcoveroverSC.AerosolindexesinSCkeptincreasingwithfluctuationduringthepast27years.TheGDPofthethreeprovincesinSCincreasedobviouslyduringthepast28years,especiallyinGuangdong,whichexhibitedthatthereissimultaneouscorrelationbetweenlightraindayswiththevariablesoflowcloudcoverandreleaseofaerosolsoverSCduring1960to2005.

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