简介：统计downscaling的二条途径在19602008期间在夏天在北京车站基于每日的最大、最小的温度观察的百分位数被用于温度极端的索引。一个人到过由起初使用文件结束分析和逐步的线性回归的下阶层的每天最大、最小的温度，然后计算极端的索引；其它到过直接下阶层由使用季节的大规模温度和geo潜在的高度记录的基于百分位数的索引。交叉验证结果证明后者途径比前者有更好的表演。然后，后者途径在北中国被用于48个气象学的车站。所有48个车站的交叉验证结果显示出在基于百分位数的索引和季节的大规模变量之间的靠近的关联。最后，在北中国的温度极端的索引的未来情形被把统计downscaling用于哈德利中心投射联合模型版本3(HadCM3)在代表性的集中小径下面的模拟4.5(RCP4.5)第五的情形联合了模型内部比较的工程(CMIP5)。结果证明每日的最大的温度的第90百分位数将在所有地s珀?珀由大约1.5talSe增加吗？？

简介：

简介：Shallowfreshwaterbodiesinpeatareascouldbeanimportantcontributortogreenhousegasesintheatmosphere.Inthisstudy,thepartialpressureofCO2inthesurfacewateroftheDianshanLakewasinvestigatedinsituinAugust2011.TheaveragepCO2inthestudyareawas2300μatmandfluctuatedwithintherangeof989–5000μatm.pCO2showedareversetrendtothevariationsofpHandDOinthesurfacewateroftheDianshanLake.ThewatertoairdiffusionfluxofCO2oftheupstream,middlelakeanddownstreamwererespectively63,33and14mmol/m2/d.Onaverage,thediffusionfluxofCO2ofthewholelakewas31mmol/m2/d.Consequently,ourresultsshowthatduringthesamplingseason,theDianshanLakeappearstobeagreatsourceofCO2.ItisalsodemonstratedthatrespirationcouldbethedominantbiochemicalreactionintheDianshanLakeinsummer.

简介：UsingNCEPreanalysisdataandanairflowtrajectorymodelbasedontheLagrangianmethod,theHybridSingle-ParticleLagrangianIntegratedTrajectory(HYSPLIT)model,thedailybackwardtrajectoriesontheheightof850hPaabovetheSouthChinaSea(SCS)areaaresimulatedfromApriltoJune.TheonsetdateoftheSCSsummermonsoonfrom1948to2009isdeterminedaccordingtothesimulatedsourceofairflowinthemonitoredareaoftheSCS.ByanalyzingtheSCSmonsoononsetdatesoverthe62years,wefoundthatthenumberofyearsinwhichtheSCSmonsoononsetisearlieraccountsfor13%,andthelateryears14%,thenormalyears73%,ofallthe62years.AnalyseswiththeLagrangianmethod,doneincomparisonwiththeothertwomethodswhichcombinewindandpotentialpseudo-equivalenttemperature,wereperformedtodeterminetheonsetdatesoftheSCSsummermonsoon.Insomeyears,thesourceofthesouthwestairflowinthemonitoredareaoftheSCSisinthesubtropicalregionbeforetheonsetoftheSCSmonsoon,sotheairflowfromthesubtropicscanbedistinguishedwiththeairflowfromthetropicsbyusingtheLagrangianmethod.Thesimulationbythetrajectorymodelindicatedthatinsomeyears,aftertheonsetofSCSsummermonsoon,theSCSwillbecontrolledbythesoutheastwindinsteadofthesouthwesterlyusuallyexpected.

简介：Duetothehighertemporalandspatialresolutionandthebetterintegralityoflong-termsatelliteinfrared(IR)BrightnessTemperature(TBB)data,aclimatologyofdeepconvectionduringsummeroverSouthChinaandtheadjacentwatersispresentedinthispaperbasedonthe1-hourlyinfraredIRTBBdataduringJune-Augustof1996-2007(except2004).TheresultsshowthatthegeographicdistributionofdeepconvectiondenotedbyTBB≤-52℃overSouthChinaandtheadjacentwatersarebasicallyconsistentwithpreviousstatisticalresultsbasedonsurfacethunderstormobservationsandlow-orbitsatellitelightningobservations.Themonthly,ten-day,five-dayanddiurnalvariationsofdeepconvectioninthisregionarefocusedoninthispaper.Thereare5activedeep-convectionareasinJune-August.Themonthlyvariationsofthedeepconvectionarecloselyassociatedwiththelarge-scaleatmosphericcirculations.ThedeepconvectionoverthelandareasofSouthChinaismoreactiveinJunewhilethatovertheSouthChinaSeaismoreactiveinJulyandAugust.Thedevelopmentofdeepconvectionisprominentlyintermittentanditsperiodisabout3to5five-dayperiods.However,thedeepconvectionoverthecoastalareasinSouthChinaremainsmoreactiveduringsummerandhasnoapparentintermittence.Theten-dayandfive-dayvariationsofdeepconvectionshowthattherearedifferentvariationsofdeepconvectionoverdifferentareasinSouthChinaandtheadjacentwaters.ThetendencyofdeepconvectionoverthelandareasofSouthChinaisnegativelycorrelatedwiththatovertheSouthChinaSea.Thediurnalvariationsofdeepconvectionshowthatthesea-landbreeze,causedbythethermaldifferencesbetweenlandandsea,andthemountain-valleybreeze,causedbythethermaldifferencesbetweenmountainsandplainsorbasins,causedeepconvectiontopropagatefromseatolandintheafternoonandfromlandtoseaaftermidnight,andtheconvectionovermountainspropagatesfrommountainstoplainsaftermidnight.Thedifferen

简介：RelativerolesofEkmantransportandEkmanpumpingindrivingsummerupwellingintheSouthChinaSea(SCS)areexaminedusingQuikSCATscatterometerwinddata.ThemajorupwellingregionsintheSCSarethecoastalregionseastandsoutheastofVietnam(UESEV),eastandsoutheastofHainanIsland(UESEH),andsoutheastofGuangdongprovince(USEG).ItisshownthattheEkmantransportduetoalongshorewindsandEkmanpumpingduetooffshorewindstresscurlplaydifferentrolesinthethreeupwellingsystems.InUESEV,EkmanpumpingandEkmantransportareequallyimportantingeneratingupwelling.TheEkmantransportincreaseslinearlyfrom0.49SvinMayto1.23SvinAugust,whiletheEkmanpumpingincreasesfrom0.36to1.22Svduringthesameperiod.InUESEH,themeanestimatesofEkmantransportandEkmanpumpingare0.14and0.07Sv,respectively,indicatingthat33%ofthetotalwind-drivenupwellingisduetoEkmanpumping.InUSEG,themeanEkmantransportis0.041SvwiththepeakoccurringinJuly,whileEkmanpumpingismuchsmaller(0.003onaverage),indicatingthattheupwellinginthisareaisprimarilydrivenbyEkmantransport.Inthesummersof2003and2007followingElNio-SouthernOscillation(ENSO)events,bothEkmantransportandEkmanpumpingdecreaseinUESEVduetotheabnormallyweaksouthwestmonsoon.Duringthesameevents,however,EkmantransportisslightlyenhancedandEkmanpumpingisweakenedinUESEHandUSEG.

简介：ByusingNCEPGODASmonthlyseasurfaceheight(SSH)and160-stationmonthlyprecipitationdatainChina,theseasonalandinterannualcharacteristicsofSSHareanalyzedoverthetropicalPacific,andcorrelationsbetweenSSHandsummerrainfallarediscussed.Theresultsareshownasfollows:(1)ThetropicalPacificSSHtakesona'V'patternintheclimaticfieldwithaneastwardopening,anditishigherinthewesternpart(inthenorthwesternpart)thanintheeasternpart(inthesouthwesternpart).Thehigh-valueareasaremorestableinthenorthwest,andthevaluerange(greaterthan0.8m)islargerinspringandsummerthaninautumnandwinter.Thehigh-valueareainthesouthwesternpartisthelargest(smallest)andmorenortherly(southerly)inspring(summer).SSHishigherinspringandautumnthaninsummerandwinterovertheequatorialzone.(2)TheinterannualanomaliesoftheSSHarethestrongestoverthetropicalwesternandsouthwesternPacificandarestrongerinwinterandspringthaninsummerandautumn.TheinterannualanomaliesarealsostrongovertheequatorialmiddleandeasternPacific.Thedistributionrangesarelargerandtheintensitiesarestrongerintheautumnandwinter.ThereisacloserelationshipbetweentheSSHinterannualanomaliesandENSOeventsinautumn,winterandspring.(3)WhenENSOeventstakeplaceinwinter,accordingtothesimultaneousrelationshipamongthetropicPacificSSH,850hPawindfieldsandthesummerprecipitationofChina,itcanbepredictedthattheprecipitationwillbesignificantlymorethannormaloverthesouthoftheYangtzeRiver,especiallyoverDongtingLakeandPoyangLakeregion,easternQinghai-TibetPlateau,Yangtze-HuaiRiverValley,easternpartofInnerMongoliaandlessthannormalovertheareaofGreatBandofYellowRiver,NorthChinaandSouthChinainsuccessivesummers.

简介：Usingtheregionalair-seacoupledclimatemodelRegCM3-POM,aseriesofnumericalexperimentsareperformedtosimulatethesummerclimatein1997and1998withdifferentcouplingtimesteps.Theresultsshowthatthecoupledmodelhasgoodperformanceonthesimulationofthesummerseasurfacetemperature(SST)in1997and1998,andthesimulationresultsofCPL1(withthecouplingtimestepat1hour)aresimilartothoseofCPL6(withthecouplingtimestepat6hours).ThecoupledmodelcanwellsimulateSSTdifferencesbetween1997and1998.Asforthesimulationofthedroughtin1997andthefloodin1998,theresultsofCPL6aremoreaccurate.Thecoupledmodelcanwellsimulatethedroughtin1997overNorthChina,andcomparedwiththeresultsoftheatmospheremodelRegCM3,thesimulationabilityofthecoupledmodelisimproved.Thecouplingmodelhasbetterabilityinthesimulationofthecirculationinthemiddleandlowlevels,andthewatervaportransportationinthecouplingmodelisreasonableinboth1997and1998.RegCM3(anuncoupledmodel)cannotcorrectlysimulatethetransportationpathdifferencesbetween1997and1998,butthecoupledmodelcansimulatethedifferenceswell.

简介：Thestudypresentedhereininvestigatedthemaincharacteristicsofcarbonmonoxideintraseasonalvariabilityandevaluateditspossibleimpactfactorsusingtheuppertroposphereandlowerstratosphere(UT/LS)AuraMicrowaveLimbSounder(MLS)observationsoverTibetanPlateauanditsadjacentareasinsummer(JunetoAugust)of2005and2006.ObservationsshowapersistentconstituentextremeextendingupintotheUT/LSthroughoutsummer,aswellasatemporallyreversedphasevariationbetweenthecarbonmonoxideandozoneinUT/LS.Theintraseasonaloscillations(ISOs)ofcarbonmonoxideduringsummerareinvestigatedbyusingmethodsofwaveletandbandpassfilteranalysis.ItisfoundthatISOsovertheTibetanPlateauhaveperiodsof10to20daysand30to60days.Theformermainlyappearedinuppertropospherewhilethelatterinlowerstratosphere.FurtheranalysisshowsthatthesetwoperiodsofISOsinUT/LSaremainlyinphasetotheactivitiesofconvectionoverthesouthoftheplateauandthevariationofSouthAsiaHigh,respectively.TheabovetwofactorsandtheirdynamicalcouplingmayberesponsibleforthetracerISOsatdifferentlevels.

简介：NutrientandChlorophyll-a(Chl-a)concentrationswereinvestigatedmonthlyalongthreetransectsextendingfromamaricultureareatoopenwatersaroundtheZhangziIslandareafromJulytoDecember2009.Theobjectiveofthisstudyistoillustratefoodavailabilitytothebottom-sowedscallopPatinopectenyessoensisundertheinfluencesoftheYellowSeaColdWaterMass(YSCWM),freshwaterinputandfeedbacksofcultivatedscallops.SignificantthermalstratificationwaspresentinopenwatersfromJulytoOctober,andsalinitydecreasedinJulyandAugustinsurfacelayersinthemariculturearea.Nutrientconcentrationsincreasedwithdepthinbothareasinsummer,butweresimilarthroughwatercolumninNovemberandDecember.Onaverage,nutrientincreasedfromsummertoautumninallcomponentsexceptammonia.Nutrientconcentrationslowerthantheminimumthresholdsforphytoplanktongrowthwerepresentonlyinupperlayersinsummer,butstoichiometricnitrogenlimitationexistedintheentireinvestigationperiod.Column-averagedChl-aconcentrationwaslowerinopenwatersthaninmaricultureareainallmonths.ItincreasedsignificantlyinmaricultureareainAugustandOctober,andwaslessvariableinopenwaters.OurresultsshowthatnutrientslimitationtophytoplanktongrowthispresentmainlyinupperlayerinassociationwithstratificationcausedbyYSCWMinsummer.FreshwaterinputandupwellingofnutrientsaccumulatedinYSCWMcanstimulatephytoplanktonproductioninmariculturearea.FarmingactivitiesmaychangestoichiometricnutrientratiosbuthavelessinfluenceonChl-aconcentration.