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14 个结果
  • 简介:Theinterestinthenationallevelsoftheterrestrialcarbonsinkanditsspatialandtemporalvariabil-itywiththeclimateandCO2concentrationshasbeenincreasing.HowtheclimateandtheincreasingatmosphericCO2concentrationsinthelastcenturyaffectthecarbonstorageincontinentalChinawasin-vestigatedinthisstudybyusingtheModifiedSheffeldDynamicGlobalVegetationModel(M-SDGVM).TheestimatesoftheM-SDGVMindicatedthatduringthepast100yearsacombinationofincreasingCO2withhistoricaltemperatureandprecipitationvariabilityincontinentalChinahavecausedthetotalvege-tationcarbonstoragetoincreaseby2.04PgC,with2.07PgCgainedinthevegetationbiomassbut0.03PgClostfromtheorganicsoilcarbonmatter.TheincreasingCO2concentrationinthe20thcenturyisprimarilyresponsiblefortheincreaseofthetotalpotentialvegetationcarbon.Thesefactorialexperimentsshowthattemperaturevariabilityalonedecreasesthetotalcarbonstorageby1.36PgCandprecipitationvariabilityalonecausesalossof1.99PgC.TheeffectoftheincreasingCO2concentrationaloneincreasedthetotalcarbonstorageinthepotentialvegetationofChinaby3.22PgCoverthepast100years.Withthechangingoftheclimate,theCO2fertilizationonChina'secosystemsistheresultoftheenhancednetbiomeproduction(NBP),whichiscausedbyagreaterstimulationofthegrossprimaryproduction(GPP)thanthetotalsoil-vegetationrespiration.OurstudyalsoshowsnotableinterannualanddecadalvariationsinthenetcarbonexchangebetweentheatmosphereandterrestrialecosystemsinChinaduetothehistoricalclimatevariability.

  • 标签: 气候变化 生态系统 二氧化碳 碳储量 大气化学
  • 简介:TheaimofthisworkisanimprovementoftheparameterizationofthesoilmoistureintheschemeoftheLandSurfaceProcessModel(LSPM)forapplicationsoverdesertareas.Infact,inverydryconditions,thewatervapourfluxplaysanimportantroleintheevaporationprocessesandinfluencestheundergroundprofilesofhumidityandtemperature.TheimprovedversionofsoilmoistureparametcrizationintheLSPMschemehasbeencheckedbyusingthedatatakenfromthedatabaseofthefieldexperimentHAPEX-Sahel(Hydrology-AtmospherePilotExperimentintheSahel,1990-1992).ModelsimulationsrefertothreedifferentstationslocatedinNiger(Fallow,MilletandTigersites)whereinputdataforLSPMandobservationsweresimultaneouslyavailable.TheresultsofsimulationstakingintoaccountthewatervapourfluxinthesoilmodelLSPM,seemtocomparebetterwiththeobservedbehaviourofsoilmoistureandturbulentheatfluxesthanthoseoverlookingthewatervapourflux,confirmingthegreatimportanceofthewatervapourinsuchdryconditions.

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  • 简介:在中国上的暴风雪的第三个阶段的energetics用ECWMF数据被分析。为中东马槽和在25282008年1月上向中国发展了的西方的和平的马槽的精力预算的分析由是关键来源和与马槽联系的旋涡动能中心的主要水池的ageostrophic风显示出geopotential的移流。精力变换学期,相互作用动能变换和baroclinic变换的大小,太小,不能解释精力中心和喷气条纹的发展。精力中心经由ageostrophicgeopotential流动的集中在他们的入口区域获得了精力,然后由一样的流动在他们的出口区域失去了精力。在入口区域,流动收敛了,增加geopotential坡度,它产生了更大的因地球自转而引起的风和更高的动能,导致在这个区域的一个上升运动。当马槽搬到中国时,流动的集中在入口区域引起的上升运动在中央、南部的中国上加强了暴风雪。

  • 标签: 中国南方 涡动动能 雪灾 能量收支 入口区域 能量中心
  • 简介:Avariationaltechnique(VT)isappliedtoestimatesurfacesensibleandlatentheatfluxesbasedonobservationsofairtemperature,windspeed,andhumidity,respectively,atthreeheights(1m,4m,and10m),andthesurfaceenergyandradiationbudgetsbythesurfaceenergyandradiationsystem(SERBS).Themethodfullyusesallinformationprovidedbythemeasurementsofairtemperature,wind,andhumidityprofiles,thesurfaceenergybudget,andthesimilarityprofileformulaeaswell.DatacollectedatFeixiexperimentstationinstalledbytheChinaHeavyRainExperimentandStudy(HeRES)Programareusedtotestthemethod.Resultsshowthattheproposedtechniquecanovercomethewell-knownunstablilityproblemthatoccurswhentheBowenmethodbecomessingular;incomparisonwiththeprofilemethod,itreducesboththesensitivitiesoflatentheatfluxestoobservationalerrorsinhumidityandthoseofsensibleheatfluxestoobservationalerrorsintemperature,whiletheestimatedheatfluxesapproximatelysatisfythesurfaceenergybudget.Therefore,thevariationaltechniqueismorereliableandstablethanthetwoconventionalmethodsinestimatingsurfacesensibleandlatentheatfluxes.

  • 标签: 热流 剖面法 变量 能量平衡 大气物理学
  • 简介:Inaccordancewithanewcompensationprincipleofdiscretecomputations,thetraditionalmeteo-rologicalglobal(pseudo-)spectralschemesofbarotropicprimitiveequation(s)aretransformedintoperfectenergyconservativefidelityschemes,thusresolvingtheproblemsofbothnonlinearcomputa-tionalinstabilityandincompleteenergyconservation,andraisingthecomputationalefficiencyofthetraditionalschemes.Asthenumericaltestsofthenewschemesdemonstrate,insolvingtheproblemofenergyconser-vationinoperationalcomputations,thenewschemescaneliminatethe(nonlinear)computationalin-stabilityand,tosomeextenteventhe(nonlinear)computationaldivergingasfoundinthetraditionalschemes,Furthercontrastsbetweennewandtraditionalschemesalsoindicatethat,indiscreteopera-tionalcomputations,thenewschemeinthecaseofnondivergenceiscapableofprolongingthevalidin-tegraltimeofthecorrespondingtraditionalscheme,andeliminatingcertainkindofsystematicalcom-putational“climatedrift”,meanwhileincreasingitscomputationalaccuracyandreducingitsamountofcomputation.Theworkingprincipleofthispaperisalsoapplicabletotheproblemconcerningbaroclin-icprimitiveequations.

  • 标签: PERFECT energy CONSERVATIVE FIDELITY and traditional
  • 简介:在在过去的几十年的陆地表面过程的理解变化在响应气候的流动改变的表面精力要求趋势和interannual可变性的知识。在我们的学习,社区陆地模型版本3.5(CLM3.5),从普林斯顿大学由最近的更新的混合reanalysis观察的表面气候数据开车,被用来在1948~2000期间获得表面精力流动的全球分布。把数据和模拟结果,长期的趋势和气候的变量和表面精力流动的interannual可变性(IAV)基于气候因为50+年的这跨度被导出并且分析。有为气候的变量和表面精力流动的强壮的长期的趋势和大IAV的区域被识别。这些分析在气候和表面流动的空间模式揭示季节的变化;然而,在为在0年不充分做的过去的锝?上的表面精力流动的趋势和IAV的空间模式为气候的变量对应于那些,显示到在气候的forcings的变化的陆地表面的复杂回答。

  • 标签: 地表能量通量 气候变化 年际变化 普林斯顿大学 空间格局 地表面
  • 简介:A落后关联分析与一个21天的宽外袍COARE解决云的模型模拟数据被进行识别在表面降雨和对流可得到的势能(披肩)之间的阶段关系并且联系了物理过程。分析表演最大值否定落后在模型领域之间的关联意味着披肩和降雨发生在附近落后小时6。最小的吝啬的披肩落后通过蒸汽冷凝作用和免职,水蒸汽集中,和热分叉的吝啬、对流的降雨而它落后经由到下雨层状的区域,蒸汽冷凝作用和免职的从对流区域的hydrometeor集中的运输的层状的降雨,水蒸汽存储,并且在下雨层状的区域上加热分叉。

  • 标签: 对流有效位能 地表降水 物理过程 相位差 显性 仿真数据
  • 简介:一些重要诊断特征为一模型物理背景在模型精力运输,变换,和周期被反映。诊断大气的精力周期是向理解并且改善数字模型的一个合适的方法。在这研究,混合时空域精力周期的明确的表达被计算,在大气的精力以内的静止、短暂的波浪的角色全球地区性的吸收和预言系统(葡萄)模型骑车被诊断并且与为2011年7月的NCEP分析数据相比。精力周期的带平均数的部件的贡献被调查解释数字模型的表演。

  • 标签: GRAPES模式 能量循环 能源运输 混合空间 时间域 诊断
  • 简介:Characteristicsofthewavesources,energypropagationandconversionforanomalousRossbywaveactivities(RWAs)alongtheWestAsianjetstream(WAJS)insummerareexaminedbasedontheNCEP/NCAR(NationalCentersforEnvironmentalPrediction/NationalCenterforAtmosphericResearch)reanalysisdatafrom1958to2003,usingthevorticitysourceequation,theEliassen-Palm(EP)flux,andthewaveenergyequationunderdiabaticheating.ThestudyaimstofindthedynamicalcausesforRWAanomaliesalongtheWAJSandtoimprovetheunderstandingofmid-highlatitudecirculationanomalies.TheresultsshowthatthenegativevorticitysourceandthestrongEPfluxdivergenceovertheMediterraneanSeaandtheNorthAtlantic-ScandinavianPeninsulaareaactasthewavesourcesforRWAanomaliesalongtheWAJS.Whentheintensityandpositionofthewavesourcesareanomalous,theexcitedeastward-propagatingRWAalongtheWAJSalsobehavesanomalously.Instrong(weak)yearsofRWA,RossbywavesexcitedbythestrongdivergenceofEPfluxesovertheIceland-ScandinavianPeninsulaarea(easttotheScandinavianPeninsula)propagateeastwardandsoutheastward.Theeastwardpropagatingwavesbecomestrengthened(weakened)afterturningsoutheastwardneartheUralMountainsandthenenteringtheAsiansubtropicalwesterlyjetstream(ASWJS)overtheCaspianSea-AralSea-Xinjiang.Thesoutheastwardpropagatingwavesalsostrengthen(weaken)afterdirectlyenteringtheASWJSovertheeasternMediterranean-theBlackSea.Furthermore,thedivergenceofEPfluxesovertheMediterraneanalsostrengthens(weakens)inthestrong(weak)years,sotheyjointlybringaboutthestrong(weak)RWAalongtheWAJS.Finally,thepertur-bationavailablepotentialenergy(PAPE)alongtheWAJS(15°-60°E)producedbydiabaticheating,isfargreaterthantheconversionfromthekineticenergyofthebasicflowintotheperturbationkineticenergyandfromtheavailablepotentialenergyofthebasicflowintoPAPE.TheRWAalongtheWA

  • 标签: NCEP NCAR 气象学 大气现象 波浪