简介:Abetterunderstandingofthelong-termglobalcarboncyclerequiredestimateofthechangesinterrestrialcarbonstorageafterthelastglacialperiod.Theresultsofsimulationatmid-Holocene(MH)fromPMIP(PaleoclimateModelingIntercomparisonProject)andthemoderndatafromCRU(ClimateResearchUnit,EastAngliaUniversity,UK)allowustousetheAtmosphere-VegetationInteractionModel(AVIM)tosimulatetheChineseterrestrialnetprimaryproductivity(NPP)at6kaBPandpresenttime.ThechangeofNPPandtotalNPPinChinafromnowtomid-Holoceneareabout54gm-2yr-1and0.63Pgyr-1,respectively,mainlyduetothebuild-upoftemperateforestandtropicalrainforest.ChineseterrestrialNPPvariationfromMHtonowiscloselyrelatedtothevariationinintensityofAsianmonsoon,whichcontrolledtheclimate-vegetationpatternchange.
简介:Inthisstudy,cloudbaseheight(CBH)andcloudtopheight(CTH)observedbytheKa-band(33.44GHz)cloudradarattheBoseongNationalCenterforIntensiveObservationofSevereWeatherduringfall2013(September-November)wereverifiedandcorrected.Forcomparativeverification,CBHandCTHwereobtainedusingaceilometer(CL51)andtheCommunication,OceanandMeteorologicalSatellite(COMS).Duringrainfall,theCBHandCTHobservedbythecloudradarwerelowerthanobservedbytheceilometerandCOMSbecauseofsignalattenuationduetoraindrops,andthisdifferenceincreasedwithrainfallintensity.Duringdryperiods,however,theCBHandCTHobservedbythecloudradar,ceilometer,andCOMSweresimilar.Thinandlow-densitycloudswereobservedmoreeffectivelybythecloudradarcomparedwiththeceilometerandCOMS.Incasesofrainfallormissingcloudradardata,theceilometerandCOMSdatawereproveneffectiveincorrectingorcompensatingthecloudradardata.Thesecorrectedclouddatawereusedtoclassifycloudtypes,whichrevealedthatlowcloudsoccurredmostfrequently.
简介:采用正交小波分解研究了近2ka来青藏高原古里雅冰芯记录的气温和冰川积累量演变多尺度特征,得到了与构成序列中主要气候事件对应的尺度分量。用130a尺度以上分量几乎可以重建冰芯记录中的主要冷暖或干湿气候事件。平均而言,温度和冰川积累量配置在大多数时间尺度上都呈正相关,即暖湿/冷干配置,但在130a尺度上是负相关,即冷湿/暖干配置。20世纪以来的快速增暖增湿发生在260a尺度上。线性增暖趋势和千年尺度分量都是暖湿/冷干配置并占有较大的方差,它们在很大程度上左右着百年尺度上的温湿配置。二者的结合直接导致千年尺度上温湿配置在8世纪出现由冷湿/暖干向暖湿/冷干气候型的转变。