简介：Inthispaper,aWindDirectionChangeIndex(WI),whichcandescribefour-dimensionalspatiotemporalchangesoftheatmosphericcirculationobjectivelyandquantitatively,isdefinedtostudyitsevolutionandseasonalvariation.ThefirstfourmodescanbeobtainedbyEOFexpansionofthezonallyaveragedWI.ThefirstmoderevealsthebasicspatialdistributionoftheannuallyaveragedWI.Thesecondmodereflectsthequasi-harmonicpartsoftheWIdeviations.Tropical,subtropicalandextratropicalmonsoonareascanbeclearlyreflectedbythismode.Thethirdmodereflectsthenon-harmonicpartsoftheWIdeviations.Itshowstheso-calledFebruaryreverseinstratosphericatmosphereaswellastheasymmetricseasonalchangesfromspringtofallandfromfalltospringduetoboththeland-seadistributioncontrastbetweentheNorthernandSouthernHemispheresandthenonlineareffectofatmosphericandoceanfluids.Thefourthmoderevealsthenorthwardadvancingoftheglobalreversedwindfieldsfromspringtosummerandtheirsouthwardwithdrawalfromsummertoautumn.

简介：Twodifferentmethodsforincorporatingdiffractioneffectintowaveactionbalanceequationbasedcoastalspectralwavemodels,WABEDandSWAN,arediscussedandevaluatedwithrespecttotheirformulations,numericalimplementations,andmodelingcapabilities.Bothmodelswereruntosimulatethewavetransformationthroughagapbetweentwoinfinitelylongbreakwatersandthatacrossanellipticalshoalobservedinlaboratorystudies,withtheemphasislaidonthediffractioninducedbyeitherobstaclesorwaveamplitudevariations.CalculationsofWABEDwerecomparedwithSommerfeld'sanalyticalsolutions,experimentalobservationsandSWANsimulations.Itisshownthatbothmethodscanpredictreasonablywavediffractionforthetwocasesstudiedherein,andafairlybetterperformanceisprovidedbyWABEDforstrongerdiffractioncase.

简介：Duetocentrifugalforcesinabendsecondarycurrentsperpendiculartothemainflowaregenerated.Becausetheycanbethereasonforimportantbedformingprocessessuchasmeanderingtheyhavetobetakenintoaccountinmorphodynamicsimulations.Theirinfluenceonthebedshearstressisproportionaltotheratioofwaterdepthandcurveradius.Thelatteroneisacurveparameterandisnotdefinedin2Ddigitalterrainmodels.Thispaperpresentsanewformulationforthebedshearstresswhichtakesintoaccounttheinfluenceofsecondarycurrentsindepthaveragedsimulationswithoutusingthecurveradius.ThenewformulationisappliedtoamorphodynamicmodeloftheWeserestuarylocatedinNorthernGermany.Itscapabilitytosimulatethedeflectionofthebedshearstressinbendsisshown.BecauseofthesmoothnessofthecurvesintheWesernosignificantdifferencesinthebedevolutioncanbeseeninthiscase.

简介：这份报纸考虑为一个关上的线性量系统构造一个直接联合量观察员的问题。建议分布式的观察员由观察员网络在一时间收敛到一致，这平均的振荡器和它被显示出的量泛音的一个网络组成观察员的每个元素在估计量工厂的指定输出的感觉。一个例子和模拟被包括说明观察员网络的性质。

简介：Thepapermainlyfocusesondescribingthemodificationmadetoanewdepth-averagedtwo-equationturbulentclosuremodelbasedontherevisedκ-ωmodelrecently.Inthecaseofsidedischargedjetswithtempera-turedifferenceandtransversecurrent,thenewmodelhasbeeninvestigatednumericallyindetail.Asapracticalexampleofapplicationtousethenewmodel,thesidedischargeofthecoolingwaterfromthreeoutletsintoanatu-ralriverononebankhasbeensimulated,andthegeomorphicvariationunderwaterhasbeentreatedsuitably.Twodepth-averagedmodels,andhavebeenused,thelaterwastheuniqueoneuptothepresent.Emphasisisplacedonthecomparativeresearchwithdifferentmodelsunderthesamecomputationalconditions.Ithasbeenverifiedthatifthedischargedflowratesarerelativelysmall,whenthepollutantplumeinthenearandtransitionalzonsispredicted,theagreementwithexperimentalandfielddatasimulatedbythemodelisbetterthanbythemodelorothermethodscommonlyusedinengineering.