简介:本文选择天山开都河流域为研究区,基于巴音布鲁克和大山口2个水文站1957—2011年的日径流量观测资料,采用年最大值法(AM)抽取径流序列样本,用线性趋势法、Mann-Kendall趋势检验和Pettitt检验分析年最大日流量、春季最大日流量和夏季最大日流量序列的变化规律;并运用广义极值分布(GEV)对标准他的最大日流量序列进行拟合,分析洪水频率的变化特征。结果表明:提取的6个最大日流量序列均不存在明显的趋势性,且突变点不显著,其中巴音布鲁克站年最大日流量、春季最大日流量和大山口站年最大日流量序列近似服从Frechet分布,而大山口站春季最大日流量、夏季最大日流量和巴音布鲁克站夏季最大日流量序列则服从Gumbel分布。1980年代以来,开都河流域洪水的发生频次明显增加;巴音布鲁克站夏季洪水次数持续增加,大山口站春季和夏季洪水次数均呈增加趋势,且春季洪水出现时间均有所提前。春季显著升温与冬季降水增加,是春季融雪性洪水出现时间和水量变化的主要原因;而夏季降雨量和降雨频率显著增加,是夏季洪水形成与频率变化的主导因素。
简介:InordertostudytheclimatevariabilitiesofthesealevelaroundtheKoreanPeninsula,tidaldataobservedatlocalstationsinKoreawerecomparedagainstthoseobtainedusingTOPEX/POSEIDON(T/P)altimetricsealeveldata.Inthecourseofourstudy,theamountofsealevelrisewasestimatedusingthetidaldatafrom9stationsselectedbyananomalycoherencyanalysis.Theresultsindicatedthatthesealevelhasrisenby0.28cmyr-1aroundtheKoreanPeninsulaoverthepasttwodecades.Theextentofsuchariseisabouttwotimeshigherthanthatoftheglobalincrease(0.1-0.2cmyr-1).However,becausemostglobalwarmingeffectsoccurredmainlyovermid-andhigh-latitudes,thislevelofchangeappearstoberealistic.Accordingtothespectralanalysis(ataspectralwindowofk=2,kisthenumberofsubdivisions),thedecadalbandofsealevelvariabilityiscomputedat30%oftheenergy.Itsspectralpeakisfoundat12.8years.Intheinterannualband,thepredominantsealevelvariabilityisinthe1.4-1.9-yearband,withasharppeakat1.6years.Asecondarypeak,althoughmarginal,hasaperiodof2.2years.BasedonourestimatesofsealevelheightfromTopex/Poseidon,thequasi-biennialperiodicityof1.6yearsistherepresentativeinterannualsealevelvariabilityintheseasadjacenttoKorea.Trendsvarygreatlyaccordingtothegeographicallocation,fromamaximumof1.0cmyr-1(thesouthernsectoroftheEastSea)toaminimumof0.17cmyr-1(thenorthernsectoroftheEastSea).Thisisfairlyconsistentwiththequalitativedescriptionalreadygivenwithreferencetotheglobalmap.AsananaloguetothepatternseeninKorea,thatoftheYellowSearevealspracticallythesametrendasthatoftheadjacentseas(0.56cmyr-1).However,inthecaseofTOPEX/POSEIDON(T/P)data,thereisnoclearevidenceofalinkagebetweentheinterannualsealevelvariabilityaroundtheKoreanPeninsulaandENSO.
简介:在最低一半的可变厚度--模型水平(LML)经常在大气的模型被使用计算象潜伏、理智的表面那样的诊断的地加热的表面流动。模仿的热带气旋(TC)上的LML的效果进化在使用theWeather研究并且预报的这研究(WRF)被调查模型。当LML被放在12m下面时,结果在TC进化上表明了LML的著名影响。TC增强率与一降低LML日益增多地减少了,但是它的最终的紧张变化是相对小的。最大的10-m风显示出不同行为到最小的海水平压力和平均azimuthally的正切的风,并且因此,风压力关系被改变LML因此改变。TC发行量是更多与更高的LML联合收缩了。表面潜伏的热流动被提高LML极大地提高,在LML的风速度在那里起了一个主导的作用。处于在LML的风速度的变化他们的侧面差别,而且他们被带从的不同高度依赖于不仅。由于提高的表面热流动,更多的强烈的潜伏的热版本发生在eyewall,它增加了暴风雨增强。更高的LML趋于生产更大的暴风雨,因此,表面磨擦被增强它接着和加热的增加的diabatic导致了更强壮的边界层流入。
简介:Thedynamicalframeworkofthenine-levelversionoftheIAPAGCMispresentedinthispaper.Theemphasisofthemodel’sdescriptionisputonthefollowingtwoaspects:(1)Amodel’sstandardatmosphere,whichisasatisfactoryapproximationtotheobservedtroposphereandlowerstratospherestandardatmosphere,isintroducedintotheequationsofthemodeltopermitamoreaccuratecalculationoftheverticaltransportterms,especiallynearthetropopause;(2)Theverticallevelsofthemodelarecarefullyselectedtoguaranteeasmoothdependenceoflayerthicknessuponpressureinordertoreducethetruncationerrorinvolvedintheunequalintervalverticalfinite-differencing.Fortestingthemodel,twokindsoflinearbaroclinicRossby-Haurwitzwaves,oneofwhichhasadynamicallystableverticalstructureandtheotherhasarelativelyunstableone,areconstructedtoprovideinitialconditionsfornumericalexperiments.Thetwowaveshavebeenintegratedformorethan300daysand100daysre
简介:CloudresolvingWeatherResearchandForecasting(WRF)modelsimulationsareusedtoinvestigatetropicalcyclone(TC)genesisefficiencyinanenvironmentwithanearbottomvortex(EBV)andanenvironmentwithamid-levelvortex(EMV).Sensitivityexperimentsshowthatthegenesistimingdependsgreatlyoninitialvorticityverticalprofiles.Thelargertheinitialcolumnintegratedabsolutevorticity,thegreaterthegenesisefficiencyis.Giventhesamecolumnintegratedabsolutevorticity,abottomvortexhashighergenesisefficiencythanamid-levelvortex.Acommonfeatureamongtheseexperimentsistheformationofamid-levelvorticitymaximumpriortoTCgenesisirrespectivewheretheinitialvorticitymaximumlocates.BoththeEMVandEBVscenariossharethefollowingdevelopmentcharacteristics:1)atransitionfromnon-organizedcumulus-scale(~5km)convectivecellsintoanorganizedmeso-vortex-scale(~50to100km)systemthroughupscalecascadeprocesses,2)theestablishmentofanearlysaturatedaircolumnpriortoarapiddropofthecentralminimumpressure,and3)amultipleconvective-stratiformphasetransition.Agenesisefficiencyindex(GEI)isformulatedthatincludesthefollowingfactors:initialcolumnintegratedabsolutevorticity,vorticityattopoftheboundarylayerandverticallyintegratedrelativehumidity.ThecalculatedGEIreflectswellthesimulatedgenesisefficiencyandthusmaybeusedtoestimatehowfastatropicaldisturbancedevelopsintoaTC.
简介:Tropospheric臭氧集中,是一种重要空气污染物质,被人工智能结构的使用建模。在伊斯坦布尔的城市里从空气污染测量车站获得的数据在组成模型被利用。为用遗传上训练的多水平的臭氧集中的评估的一个监督算法细胞的神经网络(ML-CNN)被介绍,开发,并且适用于真实数据。一个基因算法在CNN模板的优化被使用。模型结果和实际测量结果被比较并且统计上评估了。在臭氧集中的季节的变化被multilevel-CNN模型结构估计的集中有效地反映,这被观察,与0.57的关联价值查明了在之间实际并且模型结果。为技术建模的multilevel-CNN象在在空气污染应用程序在复杂媒介联系数据的另外的当模特儿的技术一样令人满意,这被显示出。
简介:The3-hour-intervalpredictionofground-leveltemperaturefrom+00houtto+45hinSouthKorea(38stations)isperformedusingtheDLM(dynamiclinearmodel)inordertoeliminatethesystematicerrorofnumericalmodelforecasts.NumericalmodelforecastsandobservationsareusedasinputvaluesoftheDLM.AccordingtothecomparisonoftheDLMforecaststotheKFM(Kalmanfiltermodel)forecastswithRMSEandbias,theDLMisusefultoimprovetheaccuracyofprediction.
简介:在这篇论文,统计远离台风和非带的上层的急流有关在暴雨之间的关联被分析。在200hPa的急流是的结果表演常常SW(90.2%)在在哪个暴雨发生的时期期间。在权利的降雨区谎言饲养喷气斧子的区域。当暴风雨加强时,喷气趋于更强壮并且变得非带。与MM4模型一起,数字模拟和诊断在8月19日为台风No.9711(Winnie)被执行到20。1997。远暴雨是紧关联词到喷气和低级台风马槽。喷气的分叉地与v部件有关。上面的水平能在底层引起关於气压变化的风集中。这是低级台风马槽的表格和暴风雨的力量的结果。由规模分析,有在在在300-hPa下面的喷气后面的正确入口区域的横向的反的循环铺平的中间的规模的一个分支,这被发现,它对维护很重要并且暴雨加强。反的循环的这个分支相对喷气的非带的特征的加强。从中央规模分叉地的域和非带的风地,我们知道更强壮的对称在喷气的二个方面由横向的循环引起了。降雨喷气有的非带的特征的反馈和加强导致暴雨的是有利的加强的积极反馈机制。
简介:Inanefforttoassessthereliabilityofsatellitealtimetersystems,theauthorsconductacomparativeanalysisofsealeveldatathatwerecollectedfromtheTOPEX/POSEIDON(T/P)altimeterand10tidegauges(TG)nearthesatellitepassinggroundtracks.TheanalysisismadeusingdatasetscollectedfrommarginalsearegionssurroundingtheKoreanPeninsulaatT/Pcyclesof2to230,whichcorrespondtoOctober1992toDecember1998.Propertreatmentoftidalerrorsisaverycriticalstepindataprocessingbecausethestudyareahasverystrongtide.WhentheT/Pdataareprocessed,theproceduresofParkandGamberoni(1995)areadaptedtoreduceerrorsassociatedwiththetide.WhentheT/Pdataareprocessedinthisway,thealiasperiodsofM2,S2,andK1constituentsarefoundtobe62.1,58.7,and173daysrepectively.ThecompatibilityoftheT/PandTGdatasetsareexaminedatvariousfilteringperiods.Theresultsindicatethatthelow-frequencysignalsoftheT/Pdatacanbeinterpretedmoresafelywithlongerfilteringperiods(suchasuptothemaximumselectedvalueof200days).WhenRMSerrorsforthe200-daylow-passfilterperiodarecomparedwithall10tidalstations,thevaluesspantherangeof2.8to6.7cm.TheresultsofacorrelationanalysisforthisfilteringperiodalsoshowastrongagreementbetweentheT/PandTGdatasetsacrossallstationsinvestigated(e.g.,p-valuesconsistentlylessthan0.001).Henceaccordingtotheanalysis,theconclusionismadethattheanalysisofsurfacesealevelusingsatellitealtimeterdatacanbemadesafelywithreasonablyextendedfilteringperiodssuchas200days.