简介：Thispaperanalyzesthecharacteristicsofsupertyphoons(STYs)overthewesternNorthPacific(WNP)from1965to2005anddescribestheseasonalvariabilityofSTYactivity.TherelationbetweenSTYactivityandtheElNio-SouthernOscillation(ENSO)aswellasthepossiblereasonfortheinfluenceoftheENSOonSTYactivityarealsoinvestigated.Theresultsshowedthataboutonefifthofthetropicalcyclones(TCs)overtheWNPcouldreachtherankofSTY.MostSTYsappearedfromJulytoNovem-berwhiletherewasahighestratiobetweennumberofSTYsandtotalnumberofTCsinNovember.MostSTYsappearedeastofthePhilippineSea.InElNioyears,affectedbyseasurfacetemperature(SST),monsoontroughandweakverticalwindshear,TCfor-mationlocationsshiftedeastwardandthereweremoreSTYsthaninLaNiayearswhentheaffectingfactorschanged.

简介：ThisstudyexaminesthemodulationoftropicalcyclogenesisovertheSouthChinaSea(SCS)bytheElNio-SouthernOscillation(ENSO)Modokiduringtheborealsummer.Resultsrevealthatthereweremoretropicalcyclones(TCs)formedovertheSCSduringcentralPacificwarmingyearsandlessTCfrequencyduringcentralPacificcoolingyears.Howdifferentenvironmentalfactors(includinglow-levelrelativevorticity,mid-levelrelativehumidity,verticalwindshear,andpotentialintensity)contributetothisinfluenceisinvestigated,usingagenesispotential(GP)indexdevelopedbyEmanuelandNolan.CompositeanomaliesoftheGPindexareproducedforcentralPacificwarmingandcoolingyearsseparately,whichcouldaccountforthechangesofTCfrequencyovertheSCSindifferentENSOModokiphases.Thedegreeofcontributionbyeachfactorisdeterminedquantitativelybyproducingcompositesofmodifiedindicesinwhichonlyoneofthecontributingfactorsvaries,withtheotherssettoclimatology.Theresultssuggestthattheverticalwindshearandlow-levelrelativevorticity,whichareassociatedwiththeENSOModoki-inducedanomalouscirculationsinMatsuno-Gillpatterns,makethelargestcontributionstotheENSOModokimodulationoftropicalcyclogenesisovertheSCSasimpliedbytheGPindex.TheseresultshighlighttheimportantrolesofdynamicfactorsinthemodulationofTCfrequencyovertheSCSbytheENSOModokiduringtheborealsummer.

简介：Thispaperdiscussesnumericalresultsfromthree-dimensionallargeeddysimulationsofanoscillatingcylinderunderprescribedmovementsinuniformflow.Sixcases,namelypurein-line,purecross-flowandtwogroupsof'FigureofEight'oscillationpatternsareunderinvestigationatReynoldsnumberRe=24000.The'FigureofEight'patternineachgroupiswithidenticalshapebutoppositeorbitaldirections.Thenumericalresultsonhydrodynamicforces,higherorderforcecomponents,andvortexsheddingmodesareextensivelystudiedandcomparedwiththemeasuredexperimentaldata.Itisfoundthatthefluidforceinphasewiththevelocity,whichrepresentstheenergytransferbetweenthefluidandthecylinder,hasoppositesignanddifferentmagnitudeduetotheoppositeorbitaldirection.Higherorderforcecomponentsincross-flowdirectionarefoundtooccuratoddnumbertimesoftheoscillatingfrequency,whileevennumbersdominatethehigherorderforcecomponentsinin-linedirection.The2Cand2Tvortexsheddingmodesarewellreproducedduetotheoppositeorbitaldirectioneffect.Comparisonsbetweennumericalandexperimentalresultsindicatethatthepresentnumericalmodelcouldbearationaltoolfortheidentificationofhydrodynamiccoefficientswhicharenormallyappliedinempiricalmodelstopredictthevortex-inducedvibrationsofslendermarinestructures.

简介：用1955年1月-2001年12月美国Scripps海洋研究所的海温再分析资料、美国NCEP再分析资料和美国气候预测中心（CPC）资料，讨论了热带太平洋ENSO与热带印度洋海温距平以及与印度洋偶极予（Dipole）的关系，研究结果发现：在垂直最大温度距平曲面（MTAL）上，热带印度洋海温距平分布存在着与热带太平洋ENSO密切相关的Dipole现象，其中最大的相关在太平洋ENSO超前印度洋Dipole一个月。但是，热带印度洋Dipole的分布与Saij定义的位置略有不同，为东北西南向，它们分别在6°S-10°S、65°E-75°E（西印度洋）和2°N-6°N、85°E-95°E（东印度洋），它是赤道印度洋的一个主要海温距平系统。另外，在热带印度洋东北部与ENSO相关的海温距平是一个上下不一致的系统，该海温距平并没有伸展到海面，从海面到20m-50m的浅薄水层，则为与赤道西南印度洋相同符号的海温距平分布。因此在海面，海温距平不存在与ENSO有关的Dipole现象，赤道印度洋Dipole只存在于次表层以下，这是赤道印度洋Dipole与ENSO不同之处。这种赤道东北印度洋表层与赤道西南印度洋表层同符号的海温距平现象，有可能是海气热力过程如感热过程造成的。热带印度洋Dipole的周期要小于EINinO3,一般为1a-6a。

简介：Correspondingtotheslidingandtheoverturningfailure,theelementarymotionmodesofcaissonbreakwaterincludethehorizontal-rotationaloscillationcoupledmotion,thehorizontalsliding-rotationaloscillationcoupledmotion,thehorizontalvibrating-upliftrockingcoupledmotion,andthehorizontalsliding-upliftrockingcoupledmotion.Themotionmodeofacaissonwilltransformfromonetoanotherdependingonthewaveforcesandthemotionbehaviorsofthecaisson.Thenumericalmodelsoffourmotionmodesofcaissonaredeveloped,andthenumericalsimulationprocedureforjointmotionprocessofvariousmodesofcaissonbreakwaterunderwaveexcitationispresentedandtestedbyaphysicalmodelexperiment.Itisconcludedthatthesimulationprocedureisreliableandcanbeappliedtothedynamicstabilityanalysisofcaissonbreakwaters.

简介：ThestudyprovidesoneofthefirstlinesofevidenceshowinglinkagesbetweenAntarcticphytoplanktonabundanceandcompositioninresponsetoENSO,basedonhistoricalreconstructionofsedimentbiomarkers.Inadditiontosedimentbiomarkers,fieldmeasuredandremotesensingdataofphytoplanktonabundancewerealsorecordedfromPrydzBay,EasternAntarctica.CommunitystructureoffieldmeasuredphytoplanktonshowedsignificantElNino/LaNina-relatedsuccessionduring1990to2002.Ingeneral,thenumberofalgaespeciesdecreasedduringElNinoandLaNinayearscomparedtonormalyears.Australsummermonthlyvariationofremotelysensedchlorophyll-a(Chl-a),particulateorganiccarbon(POC),andseasurfacetemperature(SST)indicatedthatENSOimpactedthetimingofphytoplanktonbloomsduring2007to2011.Phytoplanktonblooms(indicatedbyChl-aandPOC)precededtheincreasesinSSTduringElNinoyears,andlaggedbehindtheSSTincreasesduringLaNinayears.Stratigraphicrecordofmarinesedimentarylipid(brassicasterol,dinosterolandalkenones)biomarkersinferredthattheproportionsofdifferentalgae(diatoms,dinoflagellatesandhaptophytes)changedsignificantlybetweenElNinoandLaNinaevents.Therelativeproportionofdiatomsincreased,withthatofdinoflagellatesbeingdecreasedduringElNinoyears,whileitwasreversedduringLaNinayears.