简介:TostudytheTaiwanStrait(TS),anunusualseaarea,thenumericalmodelinmarginalseasofChinaisusedtosimulateandanalyzethetidalwavemotioninthestrait.ThenumericalmodelingexperimentsreproducetheamphidromicsystemoftheM2tideinthesouthendoftheTaiwanstrait,andconsequentlyconfirmtheexistenceofthedegenerateamphidromicsystem.Onthisbasis,furtherdiscussionisconductedontheM2systemanditsformationmechanism.ItcanbeconcludedthatthetidalwavesoftheTSisconsistedoftheprogressingwavefromthenorthentranceandthedegenerateamphidromicsystemfromthesouthentrance,inwhichtheprogressingwavefromthenorthentrancedominatesthetidalwavemotioninthestrait.Exceptfortheconvergenteffectcausedbythelandformandboundary,thedegenerateamphidromicsystemproducedinthesouthofthestraitisanotherimportantfactorforthefollowingphenomena:thelargetidalrangeinthemiddleofthestrait,theconcentrativezoneofco-amplitudeandco-phaselineinthesouthofthestrait.ThedegenerateamphidromicsystemismainlyproducedbytheincidentPacificOceantidalwavefromtheLuzonstraitandtheactionbytheshorelineandlandform.Thepositionoftheamphidromicpointiscompelledtomovetowardsouthwestuntildegeneratingbythepowerfulprogressingwavefromthenorthentrance.
简介:Asimplethree-dimensionaltidalmodelisusedtoexaminetheM2tidalcurrentdistributioninanortheasternpartoftheEastChinaSea,especiallytheverticalvariationofthecurrentintheregion.ComputedM2currentiscomparedwithobservationsavailableandfoundtobeingoodagreement.Mainfeaturesofthecalculatingmethodinthisstudyare:(1)Verticalvariationofthetidalcurrentistakenasafunetionofthedepth-meanvelocity:(2)themethodisapplicabletoavarietyoftheverticaleddyviscosities;(3)ithasafineverticalresolution,especiallyneartheseabootom.So,thismethodnotonlyenablesustogetasteadystatesolutioneasilybutalsodepictseffectsofthefrictionontheverticalvariationofthecurrentmuchbetter.
简介:WhiletheAntarcticSlopeCurrent(ASC)hasbeenintensivelystudiedfortheEastAntarcticaslopeareaandtheWeddellSea,itsfateinthewesternAntarcticPeninsula(WAP)regionremainsmuchlessknown.DatafromtwocruisesconductedneartheSouthShetlandIslands(SSIs)andtheElephantIsland(EI),oneinaustralsummerof2004andoneinaustralwinterof2006,wereanalyzedtoprovideabroadpictureofthecirculationpatternoverthecontinentalslopeofthesurveyedarea,andaninsightintothedynamicalbalanceofthecirculation.Theresultsindicatethatsouthwestwardcurrentsarepresentovertheupperslopeinthestudyarea,indicatingtheASCintheWAPregion.NeartheShackletonGap(SG)northoftheEI,thesouthwestwardslopecurrentsneartheshelfbreakarecharacterizedbyawatermasscolderandfresherthantheambientwater,whichproducescross-slopedensitygradientsandthenverticalshearofthealong-slope(oralong-isobath)velocity.Theverticalshearisassociatedwithareversalofthealong-slopecurrentfromnortheastwardatsurfacetosouthwestwardindeeperlayers,oradepth-intensificationofthesouthwestwardslopecurrents.ThewatermasswithtemperatureandsalinitycharacteristicssimilartotheobservedcoldandfreshwaterisalsorevealedonthesouthernslopeoftheScotiaSea,suggestingthatthiscoldandfreshwaterisoriginatedfromtheScotiaSeaslopeandflowssouthwestwardthroughtheSG.OvertheshelfnorthoftheSSIs,thecoldandfreshwatermassisalsoobservedandoriginatesmainlyfromtheBransfieldStrait.Inthisarea,verticalstructureofthesouthwestwardslopecurrentsisassociatedwiththeonshoreintrusionoftheupperCircumpolarDeepWaterthatcreatescross-slopedensitygradients.
简介:ViathevaluableopportunityoftheThreeGorgesReservoir(TGR)135-mfillinginJune2003,theYangtzedischargeandsuspendedsedimentconcentration(SSC)enteringtheestuaryduringtheperiodfrom15Mayto15July2003wereanalyzedtoexaminetheinstanteffectsofthefillingonthem.TheYangtzedischargeandSSCenteringtheestuaryintheperiodsbefore,duringandafterthefillingclearlyindicatedthreephases:1)thepre-storagephasecharacterizedbynaturalconditions,inwhichtheSSCincreasedwithincreasingwaterdischarge;2)thestoragephase,duringwhichtheSSCdecreaseddramaticallywithdecreasingwaterdischarge;and3)thepost-storagephase,duringwhichboththeSSCandwaterdischargeremainedatrelativelylowlevelsfirstuntiltheendofJune,thentheSSCincreasedgraduallywithincreasingwaterdischarge.ItseemsthatthetimesfortheinstanteffectsofthedecreasingdischargedownstreamfromtheupperYangtzeontheYangtzedischargeandSSCenteringtheestuaryduetotheTGR135-mfillingtotakeplacewereabout5dand1drespectively,whilebothwereabout18dforthoseoftheincreasingdischarge.Thisprobablyreflectsthebufferingandresultantlyhysteresisofthe1800-kmstretchfromtheupperYangtzetotheestuary.TheresultsarehelpfulforscientificandhydrologicalinvestigationoftheYangtzemainstreamdownstreamfromtheTGRDamandoftheestuarineandadjacentcoastalwaters.
简介:针对信息化海洋测绘这一重要问题进行了探讨,就目前存在的一些模糊认识进行了分析澄清.对相关文献涉及的数据信息准确性、语言表述严谨性和学术观点合理性问题,进行了核实和讨论,提出了我们的观点:一是认为对一些重要数据的引用有误,容易误导读者,影响到引用数据的权威性;二是认为海洋测绘一直就归属于测绘学科,而不是游离其外,更不宜将其纳入海洋学;三是认为不能简单用海图集合这个概念来代替海洋测绘的成果或数据集合,海图集合论不是海洋测绘的核心理论;四是认为海洋测绘一直就是按照纵向分离、横向融合的理念和模式发展的,不依信息化进程而改变,改变的只是它的发展深度和广度.
简介:获取近岸水体中悬浮物浓度及相关信息对于理解和管理海洋环境相当重要。历史上对于悬浮物浓度的监测往往通过费时费力的出海观测,而这种观测具有很大的局限性,每次观测只能获取一个站位的信息。为了更快更有效的获得即时悬浮物浓度相关信息,很多新的监测手段及相关科技被开发及应用。各种机载,卫星载遥感设各被用于获得及时,全面的沉积物信息。DominiqueDumnd,JeromeBijaoui在2000年刊发了关于光学传感设备可以有效应用于浅海海洋环境中以获取各种环境参数。YogeshC,AgrawalHC,Pottsmith等人于2001年尝试用激光传感设备获取水体悬浮沉积物浓度及相关粒径分布信息。FranciscoPedocchi,MarceloH,Garcia于2006年分析了关于用LaserIn-SituScatteringandTransmissometry(LISST-ST)监测悬浮物颗粒粒径及沉降速度的可靠性。HKHa,HsuWY在2009年尝试了用声学多普勒测速仪(ADV)监测可凝性沉积物浓度。ChenShuisen,FangLigang在2009年成功应用海水浊度遥感信息研究沉积物侵入黄河口影响范围。在文章中回顾了近些年大部分关于水体(海口,近岸等)沉积物浓度监测相关科技及方法。同时展现了一个ABS的具体应用实例,通过实例分析更好的了解各种监测方法的优略。详细分析了作为最近国际上应用做广泛的声学多普勒测速仪(ADV)的其优势,应用范围等相关信息。对比了传统的分析方法和近代分析方法,以此呈现未来海洋悬浮物浓度监测科技的发展趋势。
简介:针对我国船舶油污损害赔偿基金理赔工作中发现的制度性问题,分析了产生问题的原因,通过学习借鉴我国法院审判实践及国外同类基金运作经验,提出了符合实际需求的解决途径,并基于兼顾效率和公平的原则,对规范我国油污基金理赔工作的《船舶油污损害赔偿基金征收使用管理办法》提出了修订建议。