简介:DISTRIBUTIONOFLOWFREQUENCYWAVESINNORTHPACIFICANDINTRASEASONALABNORMALITYOFTHEWESTERNPACIFICSUBTROPICALHIGHLiXingliang(李兴亮)(Me...
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+.
简介:Inthispaper,anerrorsourceintheatmosphericcomponentoftheCZ(Cane-Zebiak)modelisdiscussed,whichismissingafreemodein“theexactsolutions”.However,theimprovedschemeisproposed,whichisthecomputationalschemewithadjustedwindorobserveduandvaslateralboundaries.Thesimulationsshowthatthesimulatedsurfacewindbytheimprovedschemestrong-lybearsresemblancetotheobservationexceptfortheareanearthewestandtheeastboundariesoftheintegratedarea.Theseresultssupporttheconclusionthatthewindstresssimulatedbytheim-provedschemewithlateralboundariesismuchbetterthanthatsimulatedbytheCZmodel,andshowthatinteractionbetweenlowandmiddlelatitudeshasanimportantinfluenceontheENSOvariabilityintheCZmodel.Therefore,consideringitsimpactontheCZmodelcanimprovecapa-bilityoftheCZmodelforsimulatingENSOvariability.
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.
简介:Usingfoursatellitedatasets(TOMS/SBUV,OMI,MLS,andHALOE),weanalyzetheseasonalvariationsofthetotalcolumnozone(TCO)anditszonaldeviation(TCO*),andrevealtheverticalstructureoftheOzoneLow(OV)overtheAsiancontinent.Ourprincipalfindingsare:(1)TheTCOovertheAsiancontinentreachesitsmaximuminthespringanditsminimumintheautumn.TheOzoneLowexistsfromMaytoSeptember.(2)TheOzoneLowhastwonegativecores,locatedinthelowerandtheupperstratosphere.Thelowercoreisnear30hPainthewinterand70hPaintheotherseasons.Theuppercorevariesfrom10hPato1hPaamongthefourseasons.(3)ThepositionoftheOzoneLowinthelowerandtheupperstratosphereovertheAsiancontinentshowsseasonalvariability.
简介:同位素在在地球科学跟踪并且标明日期起一个重要作用,特别87Rb-86Sr系统。与地球科学的发展,整个岩石的分析斜面足够地满足要求因为科学研究和微量分析变得越来越重要。激光脱离多收集者诱导地联合的血浆mass-spectrometry(LA-MC-ICP-MS)广泛地由于它的低样品消费在微地区的分析被使用了,高精确性在矩阵上的situ和低要求,但是当它被严重优秀辨别和集体光谱干扰的各种各样的类型限制,精确地与高Rb/Sr比率和低Sr内容特别为样品测量Sr同位素作文仍然是困难的。因而,热电离mass-spectrometry(提姆)分析同位素的比率的最精确、精确的方法,仍然是分析Sr比率的最流行的方法,特别为有低Sr内容的样品。这篇论文在low-Sr的高精确的Sr同位素分析上做系统的评论地质的样品包括微采样的技术,极端低的程序的空白的化学方法和提姆测量技术。极端低的程序的空白和提姆的联合能被用来与ng大小执行样品的高精确的微量分析,它将无疑是为Rb-Sr地球年代学,地球化学和环境研究的一个重要方向。
简介:BasedontheTaylorseriesmethodandLi’sspatialdifferentialmethod,ahigh-orderhybridTaylor–Lischemeisproposed.Theresultsofalinearadvectionequationindicatethat,usingtheinitialvaluesofthesquare-wavetype,aresultwiththirdorderaccuracyoccurs.However,usinginitialvaluesassociatedwiththeGaussianfunctiontype,aresultwithveryhighprecisionappears.Thestudydemonstratesthat,whentheorderofthetimeintegralismorethanthree,thecorrespondingoptimalspatialdifferenceordercouldbehigherthansix.Theresultsindicatethatthereasonforwhythereisnoimprovementrelatedtoanorderofspatialdifferenceabovesixistheuseofatimeintegralschemethatisnothighenough.TheauthoralsoproposesarecursivedifferentialmethodtoimprovetheTaylor–Lischeme’scomputationspeed.Amorerapidandhighprecisionprogramthandirectcomputationofthehigh-orderspacedifferentialitemisemployed,andthecomputationspeedisdramaticallyboosted.Basedonamultiple-precisionlibrary,theultrahigh-orderTaylor–LischemecanbeusedtosolvetheadvectionequationandBurgers’equation.
简介:Atime-domainmethodisappliedtosimulatenonlinearwavediffractionaroundasurfacepiercing3-Darbitrarybody.ThemethodinvolvestheapplicationofTaylorseriesexpansionsandtheuseofperturbationproceduretoestablishthecorrespondingboundaryvalueproblemswithrespecttoatime-independentfluiddomain.AboundaryelementmethodbasedonB-splineexpansionisusedtocalculatethewavefieldateachtimestep,andthefreesurfaceboundaryconditionissatisfiedtothesecondorderofwavesteepnessbyanumericalintegrationintime.Anartificialdampinglayerisadoptedonthefreesurfacefortheremovalofwavereflectionfromtheouterboundary.Asanillustration,themethodisusedtocomputethesecond-orderwaveforcesandrun-uponasurface-piercingcircularcylinder.Thepresentmethodisfoundtobeaccurate,computationallyefficient,andnumericallystable.
简介:X-raydiffractionmethodsforestimatingthemetamorphicgradeofdiagenetic,anchizoneandepizoneinmetapelitesarereviewedandappliedtosamplesfroma7000m+boreholeinwesternChinaandsurfacesamplesfromthesurroundingZoigêarea.Kübler'sillitecrystallinity(IC)measurementsprovidemoreconsistentresultsthancalculatedvaluesofpercentageofilliteintheI/SmixedlayersandpercentageofI/Smixedlayers.Down-boreholeICvaluesdisplayatypicalburialmetamorphicrelationshipbetweenstratigraphiclevelandIC.Amethodforpreparingverylowgrademetamorphicmapsisdescribed,andisogradsplottedonaregionalgeologicalmapatselectedvaluesofIC,delineatingahightemperaturediageneticzone,ananchizone,andanepizone.ThemapshowsthatICvaluesarecontrolledbystratigraphiclevelinthenorthofthestudyarea(i.e.burialmetamorphism),andproximitytoanigneousintrusivebodyinthesouth(i.e.contactmetamorphism).
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.
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
简介:210Pbwasmeasuredduringthe3rdChineseNationalArcticResearchExpeditioncruisetoinvestigateitsspatialpatterninthewesternArcticOcean,aswellasitsrelationwiththethermoclineintheCanadianBasin.Thespecificactivitiesvariedfrom0.04to2.72,<0.013to4.37,and0.1to4.85Bq/m3fordissolved,particulate,andbulk210Pb,respectively,correspondingtorespectiveaveragesof0.65,0.43,and1.08Bq/m3.IntheCanadianBasin,theminimum210Pbactivitiesoccurredinthethermocline,whichwascharacterizedbylowtemperatureof-1.52°Candsalinityof33.1.Combiningthespatialdistributionof210PbandhydrographicalcharacteristicsinthewesternArcticOcean,thisscenariowasascribedtotheeffectivescavengingof210PbwhenthePacificwaterflowedacrosstheChukchiShelf.Quantitatively,thisinterpretationwassupportedbyboththeshorterresidencetimesandhigherscavengingefficiencies(SE)ofdissolved210PbovertheChukchiShelf.ThehighestSEvalueswereobservedintheHeraldShoalandbottomwatersovertheslope.
简介:Yinshananticlineistheproductoftectono-dynamicdeformation-metamorphism.Alongtheaxisoftheanticlineexistsabrittle-ductileshearingzonewhichobviouslycontrolstheore-formation.Mineralizationoccursalongtheaxisoftheanticlineinawidthofabout1000m.Intheminingarea,volca-no-subvolcanicrocksofEarlyYanshanperiodaredividedintothreecycles:Iintermediateacidicdacitelavaanddaciteporphyry;Ⅱacidicamphibolelipariteandquartzporphyry;Ⅲintermediateandesiteporphyrite.AmongthemactivitiesofⅠandⅡcyclesaremoreintensiveandareintimatelyrelatedtothemineralization.Yinshanoredepositistheresultofcombinativeprocessesoftectono-dynamicandvolcano—magmatichydrothermalfluids,sothattherearetwocentersofmetallogeniczoning,onebeingtheaxialstrainzoneofYinshananticlinewhichisthecenteroffirstorder,andtheotherbeingporphyrystock,2ndorder.
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。
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.
简介:Thelong-termtimeseriesanalysisoftheSST(seasurfacetemperature)intheEasternEquatorialPacificOceanandthemonthlyMSL(meansealevel)inthetropicalPacificOceanisconducted.Theirquasiperiodicandlow-frequencyoscillationfeaturesarerevealed.Thesignificantperiodsoflow-frequencyfluctuationsformonthlyMSLintheareaof20°N-20°Sarebetween43.5monthsand50.0months,approximatingcloselyto47.6monthswhichisthesignificantperiodofSSTintheEasternEquatorialPacificOcean.Fromtheresultsofspace-spectralanalysis,thelow-frequencyfluctationsofmonthlyMSLinthetropicalPacificOceanappeartohaveaanticlockwisecircularly-propagatingpattern,whichis,theEasternPacificOcean(off-shoreofMexico)→theareaofNEC(NorthEquatorialCurrent)→theWesternEquatorialPacificOcean→theareaofNECC(NorthEquatorialCounter-Current)→theEasternEquatorialPacificOcean.ThephasesofthepatterncorrespondtothoseofElNinocycle.Onthebasis