简介：Stabilityparameters(Monin-ObukhovlengthL,gradientRichardsonnumberRiandbulkRischardsonnumberRi),whichareapplicableinurbanenvironment,werediscussedforwaysofcalculatingclassificationstandards.Gradientobservationsfroma325-mmeteorologicaltowerinBeijingareusedtocategorizeRibbasedonthreedifferentstandardsofstabilityproposedbyD.Golder,IrwinandHoughton.TheresultsshowthatitisrelativelyreasonablefortheregionofBeijingtoapplytheclassificationstandardbyIrwin.

简介：Anobjectiveanalysisoftropicalcyclonetracksisperformed,withwhichthetracksof131tropicalstorms(TSs)in1972-2011areseparatedintothreetypesthatmovewest-,north-andnorthwestward,denotedasTypesA,BandC,respectively.TypeA(21TSsand16%oftotal)hastheorigininthesouthwesternBayofBengal,withtheTSinaunimodaldistributionasitsseasonalfeature,occurringmainlyinautumn;18ofthe21TSs(takingup90%)landmostlyonthewesternBaycoast(westof85°E);5%ofType-ATSsattainsthewindspeedof>42.7to48.9m/s.TypeAhaslittleornoeffectonTibet.TypeB(74TSs,56.6%ofthetotal)hasitspreferableorigininthecentralBayofBengal,withtheTSinabimodaldistributionasitsseasonalpattern.Thistypedenotesthetravelinthenorthinspring,withthelandfallof67ofthe74TSs(accountingfor91%)mainlyonthemiddlecoastoftheBay(85°to95°E),and19%oftheTSsreachingthewindvelocityof>42.7to48.9m/s,whichexertgreateffectonTibetanditisthisTStrackthatgivesstrongprecipitationonitswaythroughthisregion.TypeC(36TSs,27.5%ofthetotal)hasitsmainorigininthesouthernpartofthebay,andtheseTSsareformedlargelyinautumn,movinginthenorthwestdirection,and23ofthe36TSs(64%)landmostlyonthewesternBaycoast,lastingforalongertime,withalmostnoimpactuponTibet.

简介：在这研究，Jenkinson和Collison(1977)基于兰姆(1950)的一个打字计划开发的分类计划被使用在一个每月的基础上从吝啬的海平面的压力获得发行量类型。从1951～2002的每月吝啬的海平面的压力数据被用来导出六个发行量索引并且向一个发行量目录提供27种发行量类型。最经常发生了的五种主要类型(N，NW，C，CSW，和SW)被分析在各种各样的时间规模上与哈尔滨的温度揭示他们的关系。逐步的多重回归被用来重建温度异例。发生的所有类型和三个学生的合成地图的每月吝啬的降雨打字(C，CSW，和SW)与哈尔滨的降水相关被学习。结果证明在冬季的主导的类型是类型N和NW。类型C，CSW，和SW在夏天经常发生。类型N和NW赞成一个否定温度异例并且当类型C，CSW，和SW经常导致一个积极温度异例并且对应于更多的降雨时，对应于更少的降雨。而且，一个成功的统计模型能被建立与仅仅，六之一索引并且大规模吝啬的温度。用模型，在在1951和2002之间的温度异例的77.3%全部的变化能被重建。类型C与全部的降雨有一种靠近的关系，类型C降水在在最近的年里决定哈尔滨的全部的降雨起一个主要作用。这个分类计划是有温度的一个统计downscaling模型和它的关系，降水能被用来预报地区性的气候。[出版摘要]

简介：基于地面的云分类由于在在不同大气的条件下面的云的外观的极端变化是挑战性的。质地分类技术最近被介绍了处理这个问题。一个新奇质地描述符，突出的本地二进制模式(SLBP)，为基于地面的云分类被建议。SLBP利用最经常发生的模式(突出的模式)捕获描述的信息。这个特征使SLBP柔韧到噪音。用基于地面的云图象的试验性的结果证明建议方法能比当前的最先进的方法完成更好的结果。

简介：BasedontheJointTyphoonWarningCenter(JTWC)best-trackdatasetbetween1965and2009andthecharacteristicparametersincludingtropicalcyclone(TC)position,intensity,pathlengthanddirection,amethodforobjectiveclassificationoftheNorthwesternPacifictropicalcyclonetracksisestablishedbyusingk-meansClustering.TheTClifespan,energy,activeseasonandlandfallprobabilityofsevenclustersoftropicalcyclonetracksarecomparativelyanalyzed.Thecharacteristicsoftheseparametersarequitedifferentamongdifferenttropicalcyclonetrackclusters.Fromthetrendofthepasttwodecades,thefrequencyofthewesternrecurvingcluster(accountingfor21.3%ofthetotal)increased,andthelifespanelongatedslightly,whichdiffersfromtheotherclusters.TheannualvariationofthePowerDissipationIndex(PDI)ofmostclustersmainlydependedontheTCintensityandfrequency.However,theannualvariationofthePDIinthenorthwesternmovingthenrecurvingclusterandthepelagicwest-northwestmovingclustermainlydependedonthefrequency.

简介：Basedonthetropicalcyclone(TC)observationsinthewesternNorthPacificfrom2000to2008,thispaperadoptstheparticleswarmoptimization(PSO)algorithmofevolutionarycomputationtooptimizeonecomprehensiveclassificationrule,andapplytheoptimizedclassificationruletotheforecastingofTCintensitychange.Intheprocessoftheoptimization,thestrategyofhierarchicalpruninghasbeenadoptedinthePSOalgorithmtonarrowthesearcharea,andthustoenhancethelocalsearchability,i.e.hierarchicalPSOalgorithm.TheTCintensityclassificationruleinvolvescoreattributesincluding12-HMWS,MPI,andRainratewhichplayvitalrolesinTCintensitychange.ThetestingaccuracyusingthenewminedrulebyhierarchicalPSOalgorithmreaches89.6%.ThecurrentstudyshowsthatthenovelclassificationmethodforTCintensitychangeanalysisbasedonhierarchicPSOalgorithmisnotonlyeasytoexplainthesourceofrulecoreattributes,butalsohasgreatpotentialtoimprovetheforecastingofTCintensitychange.

简介：ThisstudyinvestigatesclassificationanddiurnalvariationsoftheprecipitationechoesoverthecentralTibetanPlateaubasedontheobservationscollectedfromaC-bandvertically-pointingfrequency-modulatedcontinuous-wave(C-FMCW)radarduringtheThirdTibetanPlateauAtmosphericScientificExperiment(TIPEX-Ⅲ)2014-IntensiveObservationPeriod(2014-IOP).Theresultsshowthat51.32%oftheverticalprofileshavevalidechoeswithreflectivity>-10dBZ,and35.06%ofthevalidechoprofilesproduceprecipitationattheground(precipitationprofiles);stratiformprecipitationwithanevidentbright-bandsignature,weakconvectiveprecipitation,andstrongconvectiveprecipitationaccountfor52.03%,42.98%,and4.99%oftheprecipitationprofiles,respectively.About59.84%oftheprecipitationoccursintheafternoontomidnight,while40.16%oftheprecipitationwithweakerintensityisobservedinthenocturnalhoursandinthemorning.Diurnalvariationofoccurrencefrequencyofprecipitationshowsamajorpeakduring2100-2200LST(localsolartime)with59.02%beingthestratiformprecipitation;thesecondarypeakappearsduring1300-1400LSTwith59.71%beingtheweakconvectiveprecipitation;thestrongconvectiveprecipitationoccursmostly(81.83%)intheafternoonandeveningwithtwopeaksover1200-1300and1700-1800LST,respectively.Startingfromapproximately1100LST,precipitationechoesdevelopwithenhancedverticalairmotion,elevatedechotop,andincreasingradarreflectivity.Intenseupwardairmotionoccursmostfrequentlyin1700-1800LSTwithasecondarypeakin1100-1400LST,whilethetopsofprecipitationechoesandintenseupwardairmotionreachtheirhighestlevelsduring1600-1800LST.Theatmosphericconditionsintheearlymorningaredisadvantageousforconvectiveinitiationanddevelopment.Aroundnoon,theconvectiveavailablepotentialenergy(CAPE)increasesmarkedly,convectiveinhibition(CIN)isgenerallysmall,andasuper-dry-adiabaticlayerispresentnear