简介：Windspeedscalinginsimilaritylawinwind-generatedwavesandthedragcoefficientarestudied.Inanalyzingthedatainthewindwavechannel,itisfoundthattheu.scalinggreatlyreducesthescatterintheU10scaling.Theu.scalinghasmuchlessscatterthanthescalingusingotherwindspeeds.Thefrictionvelocityseemstoplayadistinctiveroleinwavegrowth.Theresultisimportantintheapplicationsofthesimilaritylawandinwavemodeling.Intheoryitgivesaninsightintothemechanismofwindwaveinteraction.Itisfoundthatwavesteepnessisimportantininfluencingthedragcoefficient.Thevariabilityofthecoefficientsinthecurrentlywidelyuseddragformcanbeexplainedbythedifferencesinwavesteepnessintheobservations.Adragcoefficientmodelwithwindspeedandwavesteepnessasparametersisproposed.AnexplanationforKahma'sresultthattheu.scalingdoesnotreducethescatterintheU10scalingisgiven.

简介：Inthevisiblespectrum,theatmosphericattenuationstosunlightmainlyincludeaerosolscattering,atmosphericmoleculeRayleighscatteringandozoneabsorption,whileinthenear-infraredspectrum(from650nmto1000nm),wemusttakewater-vaporabsorptionintoaccount.Basedontheatmosphericcorrectiontheory,usingspectrumirradiancedatameasuredbyInstantaneousGroundspectrometer,ozonecontentmeasuredbyMicrotopsⅡozonemonitor,water-vaporcontentandaerosolopticalthicknessmeasuredbysunphotometer,wegiveanewwaytostudywater-vaporabsorptiontosunlight,andtheresultshowsthatthemainpeakvaluesofwater-vaporabsorptioncoefficientsare0.025cm-1,0.073cm-1,0.124cm-1,0.090cm-1,0.141cm-1and0.417cm-1,whichrespectivelylieat692nm,725nm,761nm,818nm,912nmand937nm.

简介：Thediffuseattenuationcoefficient(Kd)fordownwellingirradianceiscalculatedfromsolarirradiancedatameasuredintheArcticOceanduring3rdand4thChineseNationalArcticResearchExpedition(CHINARE),including18stationsandninestationsselectedforirradianceprofilesinseawaterrespectively.Inthisstudy,thevariationofattenuationcoefficientintheArcticOceanwasstudied,andthefollowingresultswereobtained.First,therelationshipbetweenattenuationcoefficientandchlorophyllconcentrationintheArcticOceanhastheformofapowerfunction.Thebestfitisat443nm,anditsdeterminationcoefficientismorethan0.7.Withincreasingwavelength,thedeterminationcoefficientdecreasesabruptly.At550nm,itevenreachesavaluelowerthan0.2.However,theexponentfittedisonlyhalfofthatadaptedinlow-latitudeoceanbecauseofthelowerchlorophyll-specificabsorptionintheArcticOcean.Theupshotwasthat,inthecaseofthesamechlorophyllconcentration,theattenuationcausedbyphytoplanktonchlorophyllintheArcticOceanislowerthaninlow-latitudeocean.Second,thespectralmodel,whichexhibitstherelationshipofattenuationcoefficientsbetween490nmandotherwavelength,wasbuiltandprovidedanewmethodtoestimatetheattenuationcoefficientatotherwavelength,iftheattenuationcoefficientat490nmwasknown.Third,theimpactfactorsonattenuationcoefficient,includingseaiceandseawatermass,werediscussed.Theinfluenceofseaiceonattenuationcoefficientisindirectandisdeterminedthroughthecontrolofenteringsolarradiation.Thelinearrelationshipbetweenaveragingseaiceconcentration(ASIC,from158Juliandaytoobservationday)andthedepthofmaximumchlorophyllisfittedbyasimplelinearequation.Inaddition,theseawatermass,suchastheACW(AlaskanCoastalWater),directlyaffectstheamountofchlorophyllthroughtakingmorenutrient,andresultsinthehigherattenuationcoefficientinthelayerof30–60m.Con

简介：Thehollow-pipeperforatedbreakwaterisoflowreflection.Inthispaperthefunctionsofreflectioncoefficientsofbothregularandrandomwavesaretheoreticallyderived,basedontheconceptoflinearsuperimpositionofreflectedandincidentwavesandwiththetotalflowratecontinuityofintegralforminsteadofthenon-continuityoftheboundarycondition,andbasedontheconceptoflinearwavespectrumtheory.Comparisonsbetweentheoreticalresultspresentedhereandmeasurementsofmodeltestsshowreasonableagreement.

简介：Thispaperpresentsastudyondragcoefficientsundertyphoonwindforcingbasedonobservationsandnumericalexperiments.ThefrictionvelocityandwindspeedaremeasuredatamarineobservationplatformintheSouthChinaSea.Threetyphoons:SOULIK(2013),TRAMI(2013)andFITOW(2013)areobservedatabuoystationinthenortheastseaareaofPingtanIsland.Anewparameterizationisformulatedforthewinddragcoefficientasafunctionofwindspeed.Itisfoundthatthedragcoefficient(Cd)increaseslinearlywiththeslopeof0.083?10?3forwindspeedlessthan24ms?1.Toinvestigatethedragcoefficientunderhigherwindconditions,threenumericalexperimentsareimplementedforthesethreetyphoonsusingSWANwavemodel.Thewindinputdataareobjectivereanalysisdatasets,whichareassimilatedwithmanysourcesandprovidedeverysixhourswiththeresolutionof0.125°×0.125°.Thenumericalsimulationresultsshowagoodagreementwithwaveobservationdataundertyphoonwindforcing.Theresultsindicatethatthedragcoefficientlevelsoffwiththelinearslopeof0.012?10?3forhigherwindspeeds(lessthan34ms?1)andthenewparameterizationimprovesethesimulationaccuracycomparedwiththeWu(1982)defaultusedinSWAN.

简介：Thecalculativemethodofheattransfercoefficientbetweenicecoverandwaterisanalyzedconsideringtheheatbalanceaticecoverbottomfirstly.Theheattransfercoefficientiscalculatedwiththemeteorological,oceanographicdataandseaiceconditionsmeasuredontheJZ20-2Oil/GasPlatformintheBohaiSeaduringthewinterof1997/1998.Fromtheresults,itisshownthattheheattransfercoefficientissmallerinthefreezingandmeltingperiods,whichisabout0.16×10-3and0.04×10-3respectively.Inthemiddleoficeseason,theheattransfercoefficienthasalargervalue,whichisabout0.5×10-3.Lastly,theinfluencesoficethicknessandicetypeontheheattransfercoefficientarediscussed.Withtheheattransfercoefficientdeterminedabove,theoceanicheatfluxinthewinterof1997～1998iscalculated,anditstrendinthewinterisanalyzed.ThisstudycanbereferencedintheseaicenumericalsimulationandpredictionintheBohaiSea.

简介：Verticalstructuresofmomentumexchangecoefficientandsedimentconcentrationarethekeysintheresearchonestuarineandcoastalsuspendedsedimenttransport.Basedontheparabolicmixinglengthdistributionpattern,thedistributionpatternofverticalmomentumexchangecoefficientwhichissuitableforestuarineandcoastalwatersisconstructed.AcomparisonwithsteadyflowandmeasuredmomentumexchangecoefficientduringonetidalcycleintheMenaiStraitofEnglandshowsthattheresultofthispatternisclosertothemeasuredvaluesthanthoseofcommonlyusedRouse'sandvanRijn'spatterns,andthepatternisalsosuitableforestuarineandcoastalwaters.Successively,basedonthepreconditionthatmomentumexchangecoefficientisequivalenttosedimentturbulentdiffusioncoefficient,andcombiningwiththeDiffusionTheory,weobtaintheexponentialverticaldistributionpatternofsedimentconcentration,whichisalsosuitableforestuarineandcoastalwaters.Thereby,usingmeasuredverticalstratifiedsedimentconcentrationdataoftheSouthandtheNorthPassagesoftheYangtzeEstuaryandZhoushanarchipelagowatersforfittingcalculation,andcomparingtheresultswiththosefromRouse's(1938)andZhangetal.'s(1989)formulas,theresultsshowthattheexponentialverticaldistributionpatternofsedimentconcentrationobtainedinthepresentstudynotonlyovercomesthedefectofRouse'sformulathatthesurfacesedimentconcentrationwillbe0,butalsohasaholistichigherprecisionalongtheverticallinesthanthoseofRouse'sandZhangetal.'sformulas.

简介：ExperimentalstudiesonthefrictioncoefficientbetweenconcreteandthetopsurfaceofarubblemoundfoundationinChinaarereviewed.Throughcomparisonofdifferenttestresults,thedevelopmentofthisresearchiscomprehensivelyanalyzed.Anexperimentiscarriedoutintheconditionsimilartoprototype.Theprocesscurveoffrictioncoefficientwiththetestblockslidingisanalyzedandastandardfordeterminationofthefrictioncoefficientisdefined.ThevariationfeaturesofthefrictioncoefficientareanalyzedonthebasisofthepresentexperimentalresultsandotherstudiesinChina.Itisshownthatthefrictioncoefficientbetweenconcreteandthetopsurfaceofarubblemoundfoundationdecreaseswiththeincreaseofthefoundationpressure,andthefrictioncoefficientforaveryfinelevelingbedissmallerthanthatforafinelevelingbed.

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