Intrusion of Kuroshio water onto the continental shelf of the East China Sea

As a fundamental study to evaluate the contribution of the Kuroshio to primary production in the East China Sea (ECS), we investigated the seasonal pattern of the intrusion from the Kuroshio onto the continental shelf of the ECS and the behavior of the intruded Kuroshio water, using the RIAM Ocean Model (RIAMOM). The total intruded volume transport across the 200m isobath line was evaluated as 2.74 Sv in winter and 2.47 Sv in summer, while the intruded transport below 80m was estimated to be 1.32 Sv in winter and 1.64 Sv in summer. Passive tracer experiments revealed that the main intrusion from the Kuroshio to the shelf area of the ECS, shallower than 80m, takes place through the lower layer northeast of Taiwan in summer, with a volume transport of 0.19 Sv. Comparative studies show several components affecting the intrusion of the Kuroshio across the 200 m isobath line. The Kuroshio water intruded less onto the shelf compared with a case without consideration of tide-induced bottom friction, especially northeast of Taiwan. The variations of the transport from the Taiwan Strait and the east of Taiwan have considerable effects on the intrusion of the Kuroshio onto the shelf.     

Steroid and triterpenoid distributions in bransfield strait sediments: Hydrothermally-enhanced diagenetic transformations

Recent sediments from Bransfield Strait, Antarctica have been analyzed for triterpenoid and steroid hydrocarbons, sterols and steroid ketones to consider the effects of hydrothermal fluids on the sedimentary organic matter. The steroid distributions in unaltered and altered sediments are controlled more by inputs from source organisms than by the effects of hydrothermal activity, which is suggested to be limited to low temperature alteration. Nevertheless, chemical reactions occurred in altered sediments and include dehydration of sterols to sterenes, isomerization of triterpenes and sterenes, rearrangement of sterenes to diasterenes and reductive processes leading to generation of phytane from phytol via phytenes.     

海坛海峡二维潮流场数值模拟

海坛海峡为南北狭长型海峡，海峡内潮波属于前进波．本文建立了平面二维浅水波数学方程，利用欧拉-拉格朗日差分方法得到数值解，模型采用随时间变化的动边界技术，成功地模拟了海坛海峡的前进波特征，并根据实测数据进行了验证．同时计算了同潮时线和等振幅线，不同时刻的潮流场和潮流平均流速分布．计算结果表明，北部湾口M2分潮高潮时间比南部湾口早约5～6min，等振幅线范围约为2．12～2．15m．海峡内流速分布呈南北强、中间弱的特点，最大流速1m／s左右．     

弯睾鲫吸虫[Carassotrema flecterotestis(Zhukov,1971)comb.nov.]及其毛蚴发育观察

本文对取自台湾海峡棱鮻 (Lizacarinatus)消化道的弯睾软穴吸虫 (HapalotremaflecterotestisZhukov, 1971)进行重新描述,并对其毛蚴的体外发育进行观察.根据Yamaguti(1971)区分单孔科 (Haploporidae)和叉盘科 (Waretrematidae)的标准,同意李敏敏(1984)将其从单孔科移出并入叉盘科.在与叉盘科已知属比较后,我们发现该吸虫除睾丸形状外,其他主要特征与鲫吸虫属 (CarassotremaPark, 1938)的相似.因此,我们拟将其作为后者的同物异名,并将该吸虫重新命名为弯睾鲫吸虫 [Caras sotremaflecterotestis(Zhukov, 1971)comb. nov. ].实验结果表明:在室温 7~24℃(均值为 15. 3℃)条件下,其虫卵从单个卵细胞到毛蚴孵出共需 12d.     

The influence of hydrography on the distribution of phytoplankton in the southern Taiwan Strait

During the period August 1985 to May 1986, phytoplankton in the southern Taiwan Strait was collected and studied for distributional variability in relation to hydrography. The results indicated that maximum standing crops of phytoplankton occurred in October and May due to the outgrowth of certain species of diatoms and blue-green algae. The majority of phytoplankton appeared in the water in the top 25 m and occurred in distinct clusters under the influence of water movement. Multivariate analysis indicated that hydrographic parameters, which accounted for the variability of phytoplankton distribution, varied seasonally. Vertical, spatial and temporal variabilities were also apparent. The close relationship between hydrography and algal distribution justifies the use of variations in the phytoplankton population as a useful tracer of water movement.     

台湾海峡MERIS数据大气校正研究

根据MERIS(Medium Resolution Imaging Spectrometer,中等分辨率成像光谱仪)L1B产品特点,以台湾海峡为研究区域,开展MERIS数据大气校正研究。在阐述水色遥感数据大气校正原理的基础上,首先进行水体像元提取和辅助参数空间内插,获取大气校正所需的数据集。接着进行耀斑反射率计算和校正并利用加倍法精确计算瑞利散射。最后针对台湾海峡水体为清洁到轻度浑浊,提出先区分水体类别,再分别利用epsilon指数外推法进行一类水体气溶胶散射计算,和利用神经网络法计算二类水体离水反射率即ρw的方法。对大气校正的结果进行ρw负值像元数统计和光谱分析表明,该方法不仅降低ρw为负值的像元数,而且使大气校正后水体的光谱曲线同现场数据保持较好的一致性。     

New Methods of Fitting the Membership Function of Oceanic Water Masses

1　Introduction　Watermassanalysisisanimportantsubjectinphys icaloceanographystudies (PickardandEmery ,1 990 ;YeandLi,1 992 ) .Helland Hansenplottedin 1 91 6theT Scurve ,whichisafterwardsknownasoneoftheT Sdiagrams ,andsuggestedthatawatermasscanbedefinedby…     

The East Greenland Spill Jet as an important component of the Atlantic Meridional Overturning Circulation

The recently discovered East Greenland Spill Jet is a bottom-intensified current on the upper continental slope south of Denmark Strait, transporting intermediate density water equatorward. Until now the Spill Jet has only been observed with limited summertime measurements from ships. Here we present the first year-round mooring observations demonstrating that the current is a ubiquitous feature with a volume transport similar to the well-known plume of Denmark Strait overflow water farther downslope. Using reverse particle tracking in a high-resolution numerical model, we investigate the upstream sources feeding the Spill Jet. Three main pathways are identified: particles flowing directly into the Spill Jet from the Denmark Strait sill; particles progressing southward on the East Greenland shelf that subsequently spill over the shelfbreak into the current; and ambient water from the Irminger Sea that gets entrained into the flow. The two Spill Jet pathways emanating from Denmark Strait are newly resolved, and long-term hydrographic data from the strait verifies that dense water is present far onto the Greenland shelf. Additional measurements near the southern tip of Greenland suggest that the Spill Jet ultimately merges with the deep portion of the shelfbreak current, originally thought to be a lateral circulation associated with the sub-polar gyre. Our study thus reveals a previously unrecognized significant component of the Atlantic Meridional Overturning Circulation that needs to be considered to understand fully the ocean׳s role in climate.     

台湾海峡海洋捕捞业管理策略和投资方向

本文收集了１９８５￣１９９４年福建省在台湾海峡生产的具有代表性的５０对拖网渔船、１２０艘单拖渔船、４８组灯光围网渔船、３８对大围缯渔船、３１艘定置网渔船的技术参数及生产资料，计算并分析了其适正捕捞力量、经济指标，得出了一些有益的结论：（１）根据台湾海峡渔业资源，把握正确的投资方向，已成为进一步发展海洋捕捞业的关键。（２）由于台湾海峡的渔业资源正遭受越来越大的压力，为了保护渔业资源，应当限制捕捞力量     

1998年冬季台湾海峡的暖水入侵及其生态响应

就1998年2－3月台湾海峡AVHRR表层水温和SeaWiFS叶绿素数据以及当年2月20日至3月8日在台湾海峡北部海区所实施的多学科现场调查资料进行综合分析，着重探讨暖水入侵的过程及其生态响应。结果表明，1998年冬季由澎湖水道北上进入台湾海峡的高温高盐黑潮入侵水强度大于往年，在2月8日－3月13日期间不断增强，直至侵占整个海峡东侧海域，迫使低温低盐且富含营养盐的闽浙沿岸水主流顺大陆沿岸南下。这一过程向海峡西侧海域输入营养盐并使之达到适宜的水温，极可能是西侧海域出现叶绿素高值区、呈现出与往年相反的叶绿素分布态势的主控机制。分析这一现象与1997－1998年的E1 Nino事件可能存在着某种关联。