黑潮对中国近海热盐输运的季节和年际变化

应用垂向混合坐标系海洋模式（HYCOM）,对赤道以及北太平洋进行了气候态模拟和1990-1999年的模拟.给出了黑潮对我国近海热量和盐量输运的定量结果,并对其季节和年际变化特征进行了分析.气候态模拟的结果表明,黑潮对东海的热量输运与该区域的海表面热通量同量级,且呈反向变化,热量输运冬季最大,夏季最小,7月为-9×1013W,2月为2.5×1014W,春、秋为过渡季节.黑潮向南海输运的热量除夏季为负值外,其它季节均为正值.黑潮年均向东海输运热量1.67×1014 W,向南海输运热量1.5×1014W.盐量输运的变化趋势与热量一致.对1990-1999年的模拟结果进行小波分析表明,黑潮对东海热量和盐量输运具有4~7年的显著周期,且与厄尔尼诺现象密切相关.厄尔尼诺年,黑潮向东海输运的热量和盐量均有明显减小.黑潮对南海热量和盐量输运的周期约为3~4年.黑潮对南海的热量输运也与厄尔尼诺现象存在负相关关系.     

Sea surface temperature records of core ZY2 from the central mud area in the South Yellow Sea during last 6200 years and related effect of the Yellow Sea Warm Current

Sea surface temperature (SST) records in the South Yellow Sea during the last 6200 years are reconstructed by the unsaturation index of long-chain alkenones (K 37 U ’) in sediment core ZY2 from the central mud area.The SST records varied between 14.1 and 16.5°C (15.6°C on average),with 3 phases:(1) A high SST phase at 6.2-5.9 cal ka BP;(2) A low and intensely fluctuating SST phase at 5.9-2.3 cal ka BP;and (3) A high and stable SST phase since 2.3 cal ka BP.Variation of the SST records is similar to intensity of the Kuroshio Current (KC),and corresponds well in time to global cold climate events.However,the amplitude of the SST response to cooling events was significantly different in different phases.The SST response to global cooling event was weak while the KC was strong;and the SST response was strong while the KC was weak.The difference in amplitude of the SST response is possibly caused by the modulation effect of the Yellow Sea Warm Current which acts as a shelf branch of the KC and a compensating current induced by the East Asia winter monsoon.The warm waters brought by the Yellow Sea Warm Current cushion the SST decrease induced by climate cooling,and both the Kuroshio and East Asian winter monsoon play important roles in the modulation mechanism.The SST records display a periodicity of 1482 years.The same period was found in the KC records,indicating that variation of the SST records in the central South Yellow Sea is strongly affected by KC intensity.The same period was also found in Greenland ice cores and North Atlantic and Arabian Sea sediment cores,showing a regional response of marine environmental variability in the East China Seas to that in the global oceans.     

西北太平洋环流和海温数值模拟

基于Ecom-si建立了一个西北太平洋海洋数值模式,综合考虑了侧边界通量、海表面风应力、热通量、蒸发和降水等因素,模拟并分析了西北太平洋环流和海温的基本特征.模式验证结果表明,模式计算的海温与日本2008年西北太平洋实测温度走航断面资料吻合良好.模式再现了低纬度海区表层自东向西流动的北赤道流、强西边界流黑潮、东海的台湾...     

黄、东海沿岸海表温度变化与厄尔尼诺的关系

利用黄、东海沿岸8个长期水文观测站多年海表温度资料,分析黄、东海沿岸海表温度的季节和年际变化特征,重点分析在1982—1983年和1997—1998年两次厄尔尼诺年期间的异常变化,以及ENSO影响黄、东海沿岸海表温度的可能机制。结果表明,在厄尔尼诺发生年,夏季风较弱,鄂霍次克海高压加强,西太平洋副高位置偏南,强度偏强,江淮流域及长江中下游降水偏多,黄、东海沿岸海表温度偏低。黄、东海沿岸海表温度受到ENSO和PDO(太平洋年代际振荡)的影响和调制,在厄尔尼诺发生的前冬半年及当年,黄、东海沿岸海表温度偏低;在厄尔尼诺发生次年,黄、东海沿岸海表温度偏高。厄尔尼诺对黄、东海沿岸海表温度变化的影响通过海洋和大气2个通道,1982—1983年海表温度异常以负异常为主,1997—1998年海表温度异常以正异常为主;ENSO期间,北赤道流减弱,黑潮流量减少,海表温度降低。海表温度受局地气温影响显著,如果ENSO期间东亚气温升高,则黄、东海沿岸海表温度偏高。     

东海PN断面障碍层和水团的季节变化特征及其可能联系

本文利用PN断面的高分辨率海水温-盐-深剖面测量仪(CTD)温度、盐度和密度资料进行分析,发现PN断面处的水团有明显的陆架水和黑潮水的交汇特征,且随着季节的变化PN断面处的水团特征也发生明显的变化.通过观测资料还确定了PN断面处障碍层是常年存在的而且具有显著的季节变化.采用曲线族拟合的水团分析方法,根据不同季节PN断面上陆架水和黑潮水的混合特征,证明了水团混合在障碍层形成及季节变化中的重要作用,发现障碍层的季节变化与陆架水团和黑潮水团混合的季节变化密切相关.夏季,陆架水团向外海延伸,浮置于黑潮水之上,此时障碍层深度最浅,障碍层厚度最大;秋季,黑潮水离岸最近,将黑潮水与陆架水的交汇处向西压迫至陆架内,此时几乎不存在障碍层,零星存在的障碍层深度较深,厚度是一年当中最薄的;冬季,由于黑潮水的核心相对于秋季向深海移动,使得陆架混合水也相应地向外海拓展,而且此时陆架水与黑潮水的交汇处不只在混合层内而是影响到跃层,此季节障碍层是一年当中深度最深,厚度最厚的;春季,黑潮水的核心以及两种水团的交汇处相对于冬季的位置更向深海移动,所以此时PN断面上的障碍层深度和厚度相对于冬季变化不大,只是位置东移.海面风场和净热通量场通过改变...     

舟山以东浅水海域夏季水团及温盐日变化特征

为了探索舟山以东浅水海域夏季水团分布及温、盐日变化规律,基于舟山以东浅水区域时间分辨率为1h的温盐深(CTD)站点数据,首先对数据剖面取平均以研究其温、盐场结构特征,然后利用Fuzzy聚类法对该区域进行水团划分,最后根据水团划分结果分区域统计分析跃层特征,并计算温、盐日变幅极差值以研究其日变化空间的分布特征。结果表明:研究区域可分为沿岸流水团、近岸混合水团、黑潮水团、东海中-深层水团、东海中-深层混合水团;受黑潮支流与沿岸流混合下沉的影响,调查海域中部中-深层水体相对高温、低盐;沿岸流区与黑潮水区10~20m深度层的温、盐日变幅较大,与跃层深度对应较好,表层、次表层的较小,底层的近似为0;近岸混合水团跃层上界深度最大、平均强度最小,该区域表层、底层日变幅相对较大。     

吕宋海峡黑潮表层形态EOF模态分析

应用Argos表层漂流浮标资料所指示的浮标轨迹图以及基于卫星高度计资料和三维水动力模型海面高度场数据的经验正交函数(EOF)模态分析,探讨了黑潮在吕宋海峡形变的时空分布特征.结果表明:吕宋海峡黑潮的形态呈现明显的季节变化,其中跨隙形态为其最基本的形态;秋冬两季,部分黑潮水会以流套和分支的形式入侵南海,流套最西可延伸至118°E;春夏季节则儿乎不出现流套或者分支的结构,相反会有一部分南海水汇入黑潮主干.模型数据模态分析结果还再现了冬季黑潮水沿着南海北部陆坡向西入侵的形态.     

Mass-balance ecosystem model of the East China Sea

Using the Ecopath mass-balance trophodynamic model, this paper analyzed the trophic levels, flows, food web structure and ecosystem maturity of the East China Sea, and identified ecologically important functional groups in the ecosystem. The model is based on fishery resource surveys of the East China Sea in 2000, studies on diet composition and global databases such as FishBase and the Sea Around Us Project Database. The results showed that trophic levels of the functional groups are between 2.86 and 4.37, with an average of 3.32. Anchocy (Engraulis japonicus), small fishes and benthic crustaceans such as shrimps and crabs are important groups in terms of the trophic structure and flow dynamics in the East China Sea. Energy flows of most groups are between specific trophic levels, except file fish (Thamnaconus spp.), pomfret (Pampus spp.) and cephalopods. Trophic transfer efficiency of levels II, III, IV and more than V are 11.8%, 21.1%, 17.4% and 22.1–22.5%, respectively. Effects of fishery – the largest ‘consumer’ of the ecosystem – are much stronger than those exerted by biological groups in the system. The model suggests that the current fishery can further reduce the complexity of the ecosystem. Evaluations of the system indices suggest that maturity of the ecosystem is low. The conclusion of this model indicates that it was the overfishing that caused the ecosystem of the East China Sea declined, which should be taken into account as a critical reference for fisheries management in the future.     

Late Holocene paleoenvironmental changes in the southern Okinawa Trough inferred from a diatom record

We analyzed sediment diatoms from core MD05-2908 to infer climate and paleoenvironmental changes in the southern Okinawa Trough (SOT) over the past 1000 years.Because the study area is located in the East Asia monsoon area and beneath the main axis of Kuroshio Current,the climatic and hydrographical conditions are strongly influenced by both of these factors.The species used as environmental indicators,including the Kuroshio Current species (KC species) and freshwater species,were investigated in this paper.Changes in the abundance of the two groups of species revealed significant variations in water temperature and hydrography in the SOT during the Medieval Warm Period (MWP) and the Little Ice Age (LIA).From 950-1500 AD,the abundance of the KC species increased fluctuantly,while the freshwater species decreased,showing that the influence of the Kuroshio Current was intensified at that interval and the precipitation of the study area was relatively low.The KC species decreased remarkably and was maintained at a low abundance during the interval of 1500-1900 AD,which suggests that the impact of the Kuroshio Current on the SOT weakened during the period corresponding to the LIA.Moreover,the high abundance of the freshwater species at the same interval indicates a distinct increase in precipitation in northeastern Taiwan,which may be correlated to the south-detention of the rainfall belt in China caused by the southward migration of the western Pacific subtropical high.     

Ecological studies on Prochlorococcus in China seas

Prochlorococcus, a tiny oxygenic photosynthetic picoplankton with unique pigment composition, has been found to be ubiquitous and abundant in the world oceans, and has been recognized to be closely related to living resources and environmental issues. It has attracted the interest of marine biologists since its discovery, and field data on it over global oceans have accumulated rapidly in the past 10 years. In China, we have studied Prochlorococcus for 8 years, achieving a basic ecological understanding. The presence of Prochlorococcus in China seas, marginal seas of the west Pacific, was confirmed, and its distribution patterns were also brought to light. Prochlorococcus is very abundant in the South China Sea and the offshore regions of the East China Sea. It is seasonally present in the southeast part of the Yellow Sea and absent in the Bohai Sea. Temporal and spatial variations of the abundance of Prochlorococcus and their affecting factors, physiological and ecological characteristics of Prochlorococcus and their relationships to the other groups of picoplankton, and the importance of Prochlorococcus in total biomass and possible roles in living resources and environmental problems are discussed. In the future, isolation of different Prochlorococcus strains from the China seas and their physiological characteristics, genetic diversity, phylogenies and gene exploiture, etc. are important issues to be addressed.     

Ecological studies on Prochlorococcus in China seas

Prochlorococcus, a tiny oxygenic photosynthetic picoplankton with unique pigment composition, has been found to be ubiquitous and abundant in the world oceans, and has been recognized to be closely related to living resources and environmental issues. It has attracted the interest of marine biologists since its discovery, and field data on it over global oceans have accumulated rapidly in the past 10 years. In China, we have studied Prochlorococcus for 8 years, achieving a basic ecological understanding. The presence of Prochlorococcus in China seas, marginal seas of the west Pacific, was confirmed, and its distribution patterns were also brought to light. Prochlorococcus is very abundant in the South China Sea and the offshore regions of the East China Sea. It is seasonally present in the southeast part of the Yellow Sea and absent in the Bohai Sea. Temporal and spatial variations of the abundance of Prochlorococcus and their affecting factors, physiological and ecological characteristics of Prochlorococcus and their relationships to the other groups of picoplankton, and the importance of Prochlorococcus in total biomass and possible roles in living resources and environmental problems are discussed. In the future, isolation of different Prochlorococcus strains from the China seas and their physiological characteristics, genetic diversity, phylogenies and gene exploiture, etc. are important issues to be addressed.     

1997年冬季东海高氧水分布研究

根据1997年冬季东海表层、10 m层、50 m层、底层溶解氧(DO)的分布情况,在总结水团一般规律的基础上,分析了东海高氧水与台湾暖流和东海高密度水环流的关系.结果表明:东海高氧水的分布与台湾暖流、江浙沿岸流、东海高密度水环流有关,东海北部的垂向混合是充分的.     

中国海域钵水母类(Scyphomedusae)区系的研究

报道了分布在中国海域45种钵水母类的种类组成、生态类群、地理分布及其各海区区系特点,并与邻近海域相比较.研究表明:南海区钵水母类属于印度-马来区系,与马来半岛和菲律宾海域的十分相似;东海区钵水母类属于亚热带区系,与日本南部海域的较为相似;而渤海-黄海区的钵水母类属暖温带区系,与日本北部海域的十分相似.白色霞水母(Cyanea nozakii)、海蜇(Rhopilema esculentum)、黄斑海蜇(Rhopilema hispidum)和口冠水母(Stomolophus meleagris)是中国沿岸大型水母的优势种;近岸暖水性类群是中国海域的优势类群.中国海域钵水母类的地理分布与中国沿岸流和暖流特征相一致.     

An initial note on quasistationary, cold-core Lanyu eddies southeast off Taiwan Island

Drifting buoys,satellite altimetry and satellite-derived sea surface thermal images are used to identify the existence of a large cold-core,cyclonic Kuroshio fontal eddy between Hengchun Peninsula and Lanyu,southeast off Taiwan Island around March 1996.The cold eddy accompanies an offshore meander of the Kuroshio near Lanyu,about 70 km and 100 km in horizontal zonal and meridional scales,respectively.The cold eddy is different from normal Kuroshio frontal eddies for its persisting of about 2 months near Lanyu.Supporting evidence suggests that the Kuroshio intruded into the South China Sea(SCS,hereafter) forming a loop-like structure during the persisting period of the cold eddy and that similar eddies occur occasionally in the same location.Compared with the corresponding studies in the Gulf of Mexico,it is suggested that Lanyu cold eddies are SCS analogues of Tortugas eddies found in the southern Straits of Florida.Overshooting of the meandering Kuroshio when it leave the SCS and effects from conservation of potential vorticity are the possible mechanism of eddy genesis.     

海流概率统计特征

非周期性海流作为一种随机变量进行研究,只有具备较长的实测连续资料才可进行分析.本文用概率统计方法分析了黄海和东海六个多昼夜连续海流观测站的资料,得到它们的数字特征.研究结果表明,在A5号站流速模、流向和流速系数均服从一维正态分布;流速的东分量和北分量服从二维正态分布.由于海洋环境的复杂,文中结论还应用与其他海区和台站的资料加以比较验证.     

夏季东海陆架浮游植物类群结构对不同风场条件的响应分析

为探讨东海的主要物理过程对浮游植物生物量和类群结构的时空分布影响,采用高效液相色谱法分析2006年和2011年夏季东海陆架条件下的浮游植物光合色素的组成及含量,并通过CHEMTAX对浮游植物群落的结构进行分析。结果表明,不同风场条件下东海浮游植物生物量和类群结构均有显著差异。在2006年夏季航次,受弱西北风的控制,长江冲淡水向外延伸面积较大,东海陆架叶绿素a的平均浓度为1 228.6ng/L,主要特征光合色素多甲藻素(Peri)、19-己酰基氧化岩藻黄素(19-hex)、19-丁酰基氧化岩藻黄素(19-but)、玉米黄素(Zea)和二乙烯基叶绿素a(DV-Chl.a)相对较高,浮游植物以硅藻(41%)和甲藻(16%)为主要优势类群;2011年夏季航次,受强东南风影响,底层低温高盐水涌升现象明显,东海陆架叶绿素a(Chl.a)的平均浓度(2 677.9ng/L)比2006年高一倍,叶绿素b(Chlb.)、青绿藻素(Prasino)、新黄素(Neo)和别藻黄素(Allo)等光合色素浓度相对较高,硅藻(60%)在浮游植物群落中占主要优势。     

用营养动态模式估算东海区大陆架渔场渔业资源蕴藏量

引用在东海区渔场进行的"海洋生物资源补充调查和资源评价"获得的初级生产力调查结果,综合已有的研究数据,采用PARSONS和CUSHING营养动态模式,对东海区渔场的渔业资源蕴藏量进行了估算。结果表明:1996～2005年东海区大陆架渔场渔业资源平均营养级为3.531级,近10年渔业资源年平均蕴藏量为836×104t,可捕量为418×104t左右;其中东海陆架渔场平均资源量为591×104t,可捕量296×104t;黄海南部平均资源量为245×104t,可捕量123×104t。2002～2005年东海区大陆架渔场平均资源蕴藏量为855×104t,可捕量为428×104t左右;东海区大陆架单位面积渔业资源蕴藏量为14.59t/km2,可捕量7.5t/km2;有机碳与鱼的比例为10.32:1,在世界各渔场中均属于较高水平;东海的单位面积渔业资源蕴藏量为8.89t/km2,东海区海域单位面积渔业资源蕴藏量为10.20t/km2,可捕量分别为4.5t/km2和5.1t/km2,高于黄渤海区和南海,略低于福建海区。目前东海区大陆架渔场的年渔获量已达750×104t左右,远远超过估算的420×104t左右年可捕量水平,使渔业资源始终处于过度捕捞状态。要使渔业资源恢复到良好状态,至少要减少目前40%的渔获量。     

长江口外近岸环流对厄尔尼诺事件的响应

建立了东中国海环流大模型,在此基础上建立包含长江口、杭州湾及邻近海域在内的区域环流模型,较准确地刻画东中国海外海流系和沿岸流系,以及长江口外精细的流系结构。选择典型厄尔尼诺年,模拟长江口外近岸环流的异常变化,探讨长江口外近岸环流与厄尔尼诺事件的响应关系。研究表明:长江口外近岸环流与厄尔尼诺事件存在强烈的响应关系,冬季厄尔尼诺现象发生时长江口及邻近海域的环流明显减弱;台湾暖流受厄尔尼诺事件影响程度显著,流速减小、流幅变窄,台湾暖流对长江口外近岸环流的影响也因此减弱。