简介：Inthispaper,twosnowfallcasesunderdifferentweatherconditionsinnorthernChinaaresimulatedbyusingthemesoscalemodelMM5.Two-waynestingstructureofdomainsisdesignedforeachcase.AmongtheexplicitschemesofMM5,theReisnergraupelschemeisselectedtodescribethemicrophysicalprocess.Thesimulatedsnow-bandsoftwocasesarebasicallyconsistentwithobservations.Thesimulatedresultsofmicrophysicalprocessesaremainlydiscussed.Thehydrometeorsandtheirsourcesandsinksunderdifferentweatherbackgroundsaredescribed.Thefeedbackeffectsofmicrophysicalprocessesonthethermalanddynamicprocessesarealsodiscussed.Methodthatoutputstheaccumulativesourcesandsinksperhourisusedtoanalyzethedistributioncharacteristicsofhydrometeorsduringthestrongestsnowfallperiod.Twosensitivitytests(calledheattestanddragtest)areconductedtoexaminetheeffectsofmicrophysicalpro-cessesoncloudproducedbythelatentheatanddragforce.Resultshaveshownthatthedistributionofparticleshasacloserelationwithtemperature.Thetem-peratureofBeijingsnowfallisunder0℃andthereexistvaporandsolidphaseparticles,whileLiaoningsnowfallhasvapor,liquid,andsolidphaseparticlesduetothewarmtemperature.Thedistributionoftheseparticlesisnotthesameatdifferentdevelopmentstages.Fromtheanalysesofthecharacteristicsofsourcesandsinks,itisfoundthatsnowismainlyproducedbythedepositionandaccretionwithice.Cloudwateriscrucialtograupel.Themeltingofice-phaseparticlesenhancestherainproduction.Theresultsofheattestsanddragtestsrevealthatthemicrophysicalprocesseshaveinteractedwiththedynamicandthermalprocesses.Latentheatreleaseofhydrometeorsfeedsbackpositivelyonsnowfallwhilethedragforcenot.Atlast,comparisonsofsimulatedresultshavebeendonebetweenthetwodifferentkindsofsnowfallcases.ThemicrophysicalprocessesofLiaoningsnowfallcaseismorecomplicatedthanthoseofBe

简介：ByemployingtheimprovedT42L9spectralmodelintroducedbyNMC(Beijing)fromECMWFandutilizingtheFGGE-IIIbdatacoveringtheperiodof14—19June1979,theatmosphericresponsestotheabnormalsoilmoistureduringthemedium-rangeperiodhavebeenstudiednumerically.Accordingtotheinitialfieldat12GMT14June,afive-daynumericalexperimentunderdifferentconditionsofthesoilmoisturehasbeencarriedoutrespectively.ThemonthlymeanclimatologicalsoilmoistureforJunehasbeenusedinthecontrolexperimentintheinitialtimeanditchangeswithtimeaccordingtothemoisturebudgetequationatthelandsurface.Comparingwiththeexperimentswithdryorwetsoil.onecanconcludethat:1)Sourceofprecipitationovercontinentsinsummerconsistsoftheland-surfaceevaporationandthemoisturetransferfromoceans.Theirintensitiesarecomparableduringthemedium-rangetimescalewhenthesoilevaporatesitsmoisturesufficiently.Therefore,thesoilmoisturecaninfluencetheglobalprecipitationandthegeneralcirculationsignificantly;2)Byinfluencingthethermodynamicdifferencebetweenlandandsea,thesoilmoisturecanchangetheintensityofmonsoonandprecipitationdistribution;3)Theresponseoftheatmospheretotheabnormalsoilmoisturehasthecharacteristicsofgeographicaldistributionandnonlinearinteractions;4)Humanactivi-tiesontheworldcaninfluencetheenvironmentgreatly.

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简介：Thefinitevolumemethod(FVM)hasmanyadvantagesin2-Dshallowwaternumericalsimulation.Inthisstudy,thefinitevolumemethodisusedwithunstructuredtriangulargridstosimulatethetidalcurrents.TheRoeschemeisappliedinthecalculationoftheintercellnumericalflux,andtheMUSCLmethodisintroducedtoimproveitsaccuracy.Thetimeintegralisatwo-stepschemeofforecastandrevision.Fortheverificationofthepresentmethod,theStoker'sproblemiscalculatedandtheresultiscomparedwiththemathematicallyanalyticsolutions.Thecomparisonindicatesthatthemethodisfeasible.Aseaareaofaportisusedasanexampletotestthemethodestablishedhere.Theresultshowsthatthepresentcomputationalmethodissatisfactory,anditcouldbeappliedtotheengineeringfields.

简介：Inthispaperthe0-1combinedBEMisadoptedtosubdividethecomputationaldomainboundary,andtodiscretizetheGreen’sintegralexpressionbasedonLaplaceequation.TheFEMisusedtosubdividethewavesurfaceanddeducethesurfaceequationwhichsatisfiesthenonlinearboundaryconditionsonthesurface.TheequationswithpotentialfunctionandwavesurfaceheightasanunknownquantitybyapplicationofTaylorexpansionapproachcanbesolvedbyiterationwithinthetimestep.Inm-timeiterationwithinthecomputationalprocessoftimestep(n-1)ΔttonΔt,theresultsofthepreviousiterationaretakenastheinitialvalueofthetwo-orderunknowntermsinthepresentiteration.Thus,animprovedtrackingmodeofnonlinearwavesurfaceisestablished,andnumericalresultsofwavetanktestindicatethatthismodeisimprovedobviouslyandismoreprecisethanthepreviousnumericalmodelwhichignoredthetwo-orderunknowntermsofwavesurfacelocationandvelocitypotentialfunctionincomparisonwiththetheoreticalvalues.

简介：在华南海把水泡羽毛的出现特征用作一本参考书，这份报纸继续学习水泡羽毛在冷渗出物生产的地震回答活跃区域。使羽毛建模计划更合理，我们修改了原来的建模计划并且重建一个羽毛水身体模型基于它是的半径的变化，水泡在海水升起。羽毛射击集合的地震记录被前面的模拟获得。单个射击的地震记录显示出一个散布波浪领域的明显的特征和模型的周期的特征。射击集合的地震记录用prestack深度移植被处理。它的成像节的边界有好集中效果。迁居节能与更高的精确性清楚地被想象。上述的研究再次为羽毛生产的地震回答的进一步的学习打了一个基础。他们逐渐地也探查了为羽毛处理方法的一个更合适的地震数据并且为羽毛的鉴定提供了理论指导。

简介：为河环境的保存和恢复，一种沉积补充技术，它传送在水坝下面从水库挖掘或挖出到河的沉积的部分被开发并且在几个水坝尝试性地被实现了。作为补充放的沉积能外面被冲洗并且由洪水或水坝版本下游地搬运了。冲洗沉积被期望贡献降级和低流动的隧道的变化的控制。然而，因为有许多未知因素，这种技术在发展阶段。因此，系统的调查为这种技术的实际管理是必要的。在这研究，沉积涌出上并且在降级的控制上的补充沉积的地点的效果借助于斜槽实验被调查。一个二维的数字模型也被开发进一步在河恢复上调查沉积扩大的效果。数字模型享受在固定的床上存侵蚀和沉积运输。模拟结果对试验性的结果被验证。补充沉积的涌出的过程首先被调查，然后它的效果作为为河床降级的一项反措施被分析。结果如下被总结：(1)扩大在上面翻动为补充沉积和低流动的隧道的变化涌出是有效的。(2)降级的改善能在放置的二种类型的情况中被发现。改善效果上面翻动放置比的大更低翻动在固定的床上的补充地点附近的床的沉积率是的放置(3)在大更低翻动放置与相比上面翻动放置。(4)数字模型被发现作为一个预兆的工具通常成功。

简介：台风Haitang(0505)的轨道，通过了台湾岛并且再登陆了，被使用非静水力学的mesoscale成功地模仿了大气的模型MM5。Itsstructure在登陆阶段上被分析，并且在那里存在，被发现好在thetyphoon之间的关系反常移动轨道和它的不对称现象结构。thetyphoonHaitang上的台湾岛的地面的效果，它让它在登陆前旋转并且介绍“V”打反常动人的轨道inTaiwan海峡，也被模仿了。进一步的分析证明台湾岛的地面不onlydirectly影响移动轨道的台风，而且由影响它的asymmetricstructure改变台风轨道。因此，台风不对称的结构和在反常旋转的台湾岛togetherresults的地面的效果追踪。台湾岛的地面趋于增加台风的SW-NEasymmetric结构并且在从台湾海峡进入并且移动前在台风Haitang的thelandfall过程期间在SE-NW不对称的结构上有不同效果。

简介：一三维(3-D)有限体积沿海的海洋模型(FVCOM)在Benoa海湾被用于水循环和海水交换的学习，巴里岛。M2潮汐的部件在开的边界被强迫，来自六条河的分泌物在数字计算被包括。FVCOM生产的M2潮汐的举起与观察数据有一个好协议。M2潮汐的水流成功地也在ebb潮和洪水潮条件下面被计算。非线性的M2潮汐的剩余水流被海岸线几何学生产，特别包围在Serangan岛和Benoa半岛之间的狭窄的海峡。潮汐的剩余水流也在海湾嘴在海湾和一个小旋涡以内产生了二个小旋涡。河分泌物影响的咸度分发能成功地被计算，在数字计算和观察结果有好关联的地方(r2)0.75。最后在Benoa海湾交换以便检验海水，追踪住处时间的方法和计算的Lagrangian粒子被使用。到涌出海水的粒子运输的机制被两个方法清楚地描绘。

简介：Threenumericalexperimentshavebeencarriedoutbyusingaspectralbarotropicprimitiveequationmo-del.Itisfoundthattheresultsobtainedarequitesimilartothosewiththebarotropicfilteredmodel.Themainresultsreadasfollows:(1)Inthecasewithsymmetricorographyorwithoutorography,ifthemotionissymmetric(withre-specttotheequator,thesameistruehereafter)attheinitialinstant,thenitwouldbesymmetricafterwards.(2)Theantisymmetricorographydistributioncouldcauseantisymmetricmotion,andtheoriginalsym-metricmotionmightbecomeasymmetric.Inordertoexplaintheaboveresults,ithasbeenprovedthattheyaretheoreticallyvalid.Anditisfoundthatifthemotionisantisymmetricattheinitialinstant,thenitwouldbecomeasymmetric.Therefore,nopureantisymmetricmotioncouldbemaintained.

简介：台风Rananim(0414)被从分析的中心和暴风雨(帽子)的预言使用非静水力学的先进地区性的预言系统(ARPS)模仿了。Rananim的预言通常用新一代CINRADDoppler雷达数据与ARPS被改进了。有那或没有使用数据显示出的雷达的数字实验与在ARPS的光线的速度数据能改变的吸收雷达为起始的域建模在对流层的中间和高水平的风域；热带气旋(TC)的好特征被介绍进起始的风，TC的风速度南方的x部件被增加那么它向西是y部件。他们导致在时间TC轨道预报改进在以后乍见陆地。混合混合比率的比率，温度，云水混合比率和雨水的水蒸汽的地被使用雷达反射率数据也改进了。模型对hydrometeors的介绍的起始的反应被增加了。水平模型分辨率在紧张预报上有重要影响，这被显示出，由极大地改进特殊预报TC的TC降雨，和重暴风雨，以及它有时间的分发和变化。

简介：Thispaperextendsapredictionmodelformulti-directionalrandomwavetransformationbasedonanenergybalanceequationbyMasewiththeconsiderationofwaveshoaling,refraction,diffraction,reflectionandbreaking.Thisnumericalmodelisimprovedby1)introducingWen'sfrequencyspectrumandMitsuyasu'sdirectionalfunction,whicharemoresuitabletothecoastalareaofChina;2)consideringenergydissipationcausedbybottomfriction,whichensuresmoreaccurateresultsforlarge-scaleandshallowwaterareas;3)takingintoaccountanon-lineardispersionrelation.PredictionsusingtheextendedwavemodelarecarriedouttostudythefeasibilityofconstructingtheAiHuayachtportinQingdao,China,withacomparisonbetweentwoportlayoutsindesign.Wavefieldsinsidetheportfordifferentincidentwavedirections,waterlevelsandreturnperiodsaresimulated,andthentwokindsofparametersarecalculatedtoevaluatethewaveconditionsforthetwolayouts.AnalysesshowthatLayoutIisbetterthanLayoutII.Calculationresultsalsoshowthattheharborwillbecalmfordifferentwavedirectionsunderthedesignwaterlevel.Onthecontrary,thewaveconditionsdonotwhollymeettherequirementsofayachtportforshipberthingundertheextremewaterlevel.Forsafetyconsideration,theelevationofthebreakwatermightneedtobeproperlyincreasedtopreventwaveovertoppingundersuchwaterlevel.Theextendednumericalsimulationmodelmayprovideaneffectiveapproachtocomputingwaveheightsinaharbor.

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简介：ThecirculationofYellowSeaColdWaterMass(YSCWM)intheSouthernYellowSeaisinvestigatedusingadiagnostic2DMITgcmmodel.Theresolutionofthecomputationalgridis900minthehorizontaland2mintheverticalwhereaninitialtemperaturedistributioncorrespondingtoatypicalmeasuredYellowSeaColdWaterMasswasapplied.TheexistenceofYSCWMthatcausesfluiddensitydifference,isshowntoproducecounter-rotatingcyclonichorizontaleddiesinthesurfacelayer:theinneroneisanti-cyclonic(clockwise)andrelativelyweaker(8–10cms-1)whiletheouteroneiscyclonic(anti-clockwise)andmuchstronger(15–20cms-1).ThisresultisconsistentwiththesurfacepatternobservedbyPangetal.(2004),whohasshownthatamesoscaleanti-cycloniceddy(clockwise)existsintheupperlayerofcentralsouthernYellowSea,andabasin-scalecyclonic(anticlockwise)gyreliesoutsideoftheanti-cycloniceddy,basedonthetrajectoriesanddriftingvelocitiesof23drifters.Belowthethermocline,thereisananti-cyclonic(clockwise)circulation.ThiscomplexcurrenteddysystemisconsideredtobecapableoftrappingsuspendedsedimentsanddepositingthemnearthefrontbetweenYSCWMandthecoastalwatersofftheSubeicoast,providinganexplanationonthesedimentdepthandsizedistributionofmudpatchesintheSouthernYellowSea.Moreover,sensitivetestscenariosindicatethatvariationsofbottomfrictiondonotsubstantiallychangethemainfeaturesofthecirculationstructure,butwillreducethebottomcurrentvelocity,increasethesurfacecurrentvelocityandweakentheupwellingaroundthefrontalarea.

简介：TheMultipleColumnPlatform(MCP)semi-submersibleisanewlyproposedconcept,whichdiffersfromtheconventionalsemi-submersibles,featuringcentrecolumnandmiddlepontoon.Itisparamounttoensureitsstructuralreliabilityandsafeoperationatsea,andarigorousinvestigationisconductedtoexaminethehydrodynamicandstructuralperformanceforthenovelstructureconcept.Inthispaper,thenumericalandexperimentalstudiesonthehydrodynamicperformanceofMCPareperformed.Numericalsimulationsareconductedinboththefrequencyandtimedomainsbasedon3Dpotentialtheory.Thenumericalmodelsarevalidatedbyexperimentalmeasurementsobtainedfromextensivesetsofmodeltestsunderbothregularwaveandirregularwaveconditions.Moreover,acomparativestudyonMCPandtwoconventionalsemi-submersiblesarecarriedoutusingnumericalsimulation.Specifically,thehydrodynamiccharacteristics,includinghydrodynamiccoefficients,naturalperiodsandmotionresponseamplitudeoperators(RAOs),mooringlinetensionarefullyexamined.ThepresentstudyprovesthefeasibilityofthenovelMCPanddemonstratesthepotentialpossibilityofoptimizationinthefuturestudy.

简介：Bystatisticanddynamicanalyses,wehavecometothefollowingconclusions:(1)TheECMWFmedium-termnumericalforecastcanforecastmedium-termactivityofsubtropicalhigh,andtheaccuracyrateofforecastcannothavelargeimprovementbytranslationalcorrections.(2)TheimportantcausefortheECMWFmedium-termnumericalforecasttohaveerrorsin1998isthattheastronomicaltideisnotincludedinthemodel.(3)TwoindexesarefoundfromwhichitcanbejudgedthatECMWFmedium-termnumericalforecastwillhaveerrorsiftheastronomicaltideisignoredinthemodel:①Whenthe54.7°lineunderthemoonofthenodicalmonthastronomicalsingularitiescoincideswiththetrough-lineofthesubtropicaljetflowfrom50°Eto150°Eonthe500hPalevelat2000L.T.ofthesameday,andisapproximatelyvertical(α>60°)withtheisotherm,thentheday0-2daysaftertheappearanceofthenodicalmonthastronomicalsingularitiesisdefinedastheinitialday.Theninthreesuccessivedaysaftertheinitialday,ECMWFmedium-termnumericalforecastofthenorthernlatitudeofthe588lineat120°Ewillhavecontinuouserrorsaslargeastwolatitudes(7/9).Otherwise,itwon'thavecontinuouserrors(13/13).②Otherwise,ifthe54.7°lineisintherangeofalowpressurebetweentwohighpressures,thenthereisadispersiveerroronthedayofthenodicalmonthastronomicalsingularities(5/7).Thereisnotanyerror(6/6)otherwise.

简介：Afamilyofunconditionallystabledirectintegrationalgorithmwithcontrollablenumericaldissipationsisproposed.Thenumericalpropertiesofthenewalgorithmsarecontrolledbythreeparametersα,βandγ.Bytheconsistentandstabilityanalysis,theproposedalgorithmsachievethesecond-orderaccuracyandareunconditionallystableundertheconditionthatα≥-0.5,β≤0.5andγ≥-(1+α)/2.Comparedwithotherunconditionallystablealgorithms,suchasChang’salgorithmsandCRalgorithm,theproposedalgorithmsarefoundtobesuperiorintermsofthecontrollablenumericaldampingratios.Theunconditionalstabilityandnumericaldampingratiosoftheproposedalgorithmsareexaminedbythreenumericalexamples.Theresultsdemonstratethattheproposedalgorithmshaveasuperiorperformanceandcanbeusedexpedientlyinsolvinglinearelasticdynamicsproblems.

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简介：BasedontherealcaseofafrontalprecipitationprocessaffectingSouthChina,27controllednumericalexperimentswasmadefortheeffectsofhydrostaticandnon-hydrostaticeffects,differentdrivingmodels,combinationsofinitial/boundaryconditions,updatesoflateralvaluesandinitialtimelevelsofforecast,onmodelpredictions.Featuresabouttheimpactofinitial/boundaryconditionsonmesoscalenumericalweatherprediction(NWP)modelareanalyzedanddiscussedindetail.Sometheoreticallyandpracticallyvaluableconclusionsaredrawn.ItisfoundthattheoveralltendencyofmesoscaleNWPmodelsisgovernedbyitsdrivingmodel,withtheinitialconditionsshowingremarkableimpactsonmesoscalemodelsforthefirst10hoursofthepredictionswhileleavinglateralboundaryconditionstotakecaretheperiodbeyond;thelatteraffecttheinnerareaofmesoscalepredictionsmainlythroughthepropagationandmovementofweathersignals(waves)ofdifferenttimescales;initialvaluesofexternalmodelparameterssuchassoilmoisturecontentmayaffectpredictionsofmorelongertimevalidity,whilefastsignalsmaybefilteredawayandonlyinformationwithtimescale4timesaslargeasormorethantheupdatedperiodofboundaryvaluesmaybeintroduced,throughlateralboundary,tomesoscalemodels,etc.Someresultsmaybetakenasimportantguidanceonmesoscalemodelanditsdataassimilationdevelopmentsofthefuture.

简介：ThecalculatingschemesofunderlyingsurfaceprocessesinthemodeldescribedbyLietal.(1989)aremodifiedwithinclusionofsimplelandsurfaceprocessesandoceanicmixedlayerprocesses,thenasimulationonthezonalwindalong90°EfromtheNortherntotheSouthernHemispherewithmoun-tainsisperformed.Comparisonsoftheresultsandtheobservationsshowthatthemodifiedmodelnotonlyhasanexcellentstabilityincalculationbutalsocanbetterdisplaytheseasonalchangeofthewindfield,theabilityofthepresentmodelisimprovedascomparedwiththatofthepreviousone.Basedonthesimulations,theauthorsinvestigatetheeffectsofQinghai-XizangPlateausnowcoverontheformationofSouthAsianmonsoonbythickcningthesnowdepthandbyincreasingthesnowalbedo.Themainresultsarcasfollows:ThesummermeridionalcirculationoverthesouthofthePlateauanditsvicinityisweakeued,andtheprecipitationreduced.However,overthenortherntropics,thecirculationisenhanced,andtheecipitationisincreased,andthelandandtheairaboveitbecomewarmer,thetropicaleasterlyjetisweakened.