Basic characteristics and forming mechanism of the sharp thermocline in the Bohai Sea, Huanghai Sea and northern East China Sea

- On the basis of the fact that the sharp thermocHne in the Bohai Sea and the northern Huanghai Sea is often distributed in the deep valley areas, it has been long thought that the reason of the formation of the sharp thermocHne is that the cold water can be easily kept in valleys. But recent investigations carried out in the southern Huanghai Sea in summer show that all of the sharp thermocHne areas were distributed in the shallow sloping-bottom areas but not in the deep valley areas. Only in autumn would the sharp thermoclines translate to the deep valley areas. In summer, they are characterized by shallow upper mixing layer and thin thickness in the southern Huanghai Sea. In addition to entrainment coming from lower boundary of upper mixing layer the entrainment from upper border of bottom homogeneous layer induced by tidal mixing also plays an important role in the growth and decay of thermoclines in these seas.     

黄海、东海海区水体散射特性研究

半分析模型是水色遥感反演算法的研究热点,而水体后向散射系数对建立半分析水色反演模型是非常重要的参数.通过对黄海、东海海区的水体固有光学量测量数据进行分析,得到水体总后向散射系数与水体总散射系数的关系为乘幂关系,颗粒物后向散射系数随光谱变化的指数在高低浑浊度水体有很大差异,并初步得到黄海、东海海区水体的后向散射系数与总悬浮物浓度的关系,从而为水色半分析模型建立和水光学辐射计算提供一组散射特性模型.     

夏季黄海、东海鞭毛虫的丰度与悬浮颗粒物的关系

对2001年8月黄海中部和南部以及东海北部海洋鞭毛虫的丰度及其与悬浮颗粒物的数量关系进行了研究,发现调查区域内的鞭毛虫丰度为44~12 600个/cm3,它们在悬浮颗粒中所占的比例可达60%以上.悬浮颗粒物的粒径谱可以分为平缓型、驼峰型、浮游生物型和混合型.鞭毛虫丰度的变化与悬浮颗粒物的数量分布具有相似的变化趋势,整体上来说,两者数量的相关性显著,而不同的粒径谱类型中,两者的关系有不同的特点.对两者的数量关系进行了初步的探讨,并为今后海域生态调查中鞭毛虫丰度的快速估计提供一条新的途径.     

Distribution and its mechanism of suspended particulate matters in the southern Huanghai Sea and the East China Sea in summer

Water temperature,turbidity,chlorophyll-a and suspended sediment concentration (SSC) were investigated at 61 stations of eight sections in the southern Huanghai Sea (HS) and the East China Sea (ECS) during the summer (28 June to 15 July) of 2006.The horizontal distribution of suspended parti culate matter (SPM) displayed a high concentration inshore and a low value offshore.The maximum value can reach 10.4 mg/dm 3,which can be found at the Changjiang River mouth.For the same site,the SSC was generally higher at the bottom than on the surface.In the vertical direction,distribution characteristics of turbidity can be divided into two types:in the southern HS high values at the bottom while low values on the surface,and in the ECS high values inshore with low values offshore.The thermocline in the HS and the Taiwan Warm Current in the ECS could be important factors preventing the SPM from diffusing upward and seaward.Even the typhoon Ewiniar was not able to work on the major sediment transport under the thermocline during the observation.     

Quantitative relationship between flagellate abundance and suspended particle density in Huanghai Sea and East China Sea in summer

1 IntroductionInthepast30a, withthewidespread acceptanceof the im portant role played by m icroorganisms inaquaticsystems, thestructure, functionandtheirim -plications ofm icrobialloop have becom e a focus ofattention on m arine ecological studies (Sherr …     

热带海洋温跃层深度与南海夏季风强度关系探讨

计算了1975～1999年南海夏季风强度指数,针对季风强、弱年进行太平洋至印度洋20℃等温面的深度(温跃层深度)距平场合成分析,得到强、弱季风年温跃层深度距平的4种分布形式.使用历年季风强度指数与各月温跃层深度距平作相关计算,发现孟加拉湾和赤道中太平洋的深度距平与季风强度具有很好的正相关,台湾以东海域呈较高的负相关,可作为季风预测的重要因子.     

Ecological characteristics of Ostracoda in the South Huanghai Sea and East China Sea

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Spatial and temporal variations of macro-and mesozooplankton community in the Huanghai Sea (Yellow Sea) and East China Sea in summer and winter

The study was conducted during two cruises of June–August 2006 (summer),and January–February 2007 (winter) in the Huanghai (Yellow) Sea and East China Sea.Spatial and temporal variations of zooplankton abundance,biomass and community structure and its relation to currents and water masses over the continental shelf were examined.A total of 584 zooplankton species/taxa and 28 planktonic larvae were identified during the two surveys.Copepods were the most abundant component among these identified groups.Zooplankton abundance and biomass fluctuated widely and showed distinct heterogeneity in the shelf waters.Five zooplankton assemblages were identified with hierarchical cluster analysis during this study,and they were Huanghai Sea Assemblage,Changjiang Estuary Assemblage,Coastal Assemblage,East China Sea Mixed-water Assemblage and East China Sea Offshore Assemblage.Seasonal changes of zooplankton community composition and its geographical distribution were detected,and the locations of the faunistic areas overlap quite well with water masses and current systems.So we suggest that the zooplankton community structure and its changes were determined by the water masses in the Huanghai Sea and East China Sea.The results of this research can provide fundamental information for the long-term monitoring of zooplankton ecology in the shelf of Huanghai Sea and East China Sea.     

东海、黄海鱼类群落结构的季节变化研究

根据2000年春(4月)、夏(6月)、秋(9月)、冬(12月)四季东海、黄海底拖网鱼类资源调查资料,分析了该海域的鱼类群落结构的四季变化特征.四季全部调查海域中出现的优势鱼种有8种:带鱼、小黄鱼、黄鲫、发光鲷、细条天竺鲷、鳀、鳄齿鱼和刺鲳,其中带鱼和小黄鱼是常年优势种.鱼种季节迁移变化以黄海南部波动最大,东海中部相对较为稳定,东海北部稳定性介于两者之间.生物多样性指数中丰富度指数(D)和Shannon-Wiener多样度指数(H')变化趋势一致,在春、夏两季3个区域相差不大,而在秋、冬两季黄海南部与东海北部和中部有明显分异;种类均匀度指数(J')在四季节3个区域之间相差不大.在暖季(夏、秋)南部鱼类呈向北迁移,而在冷季(冬、春)北部的鱼类有向南迁移的趋势.     

中国近海温跃层判定方法的研究

根据东海以及南海东北部多组资料,探讨了拟阶梯函数法和垂向梯度法在浅海区（水深〈200m）、陆架坡折海域（水深在200m左右）和深水开阔海区（水深〉200m）的应用情况,分析了温跃层在陆架坡折海域的水平衔接问题。对比分析表明：在浅海区,两种方法结果比较一致,特别对某些垂直温度梯度较弱的曲线,拟阶梯函数法和实际水文廓线符合更好。陆架坡折海域,垂向梯度法对于温度梯度相对较弱的跃层刻画不好,而拟阶梯函数法可以对较弱温跃层进行判定,与实际垂直水文结构一致。深水开阔区域,垂向梯度法所得温跃层特征量与实际符合较好,而拟阶梯函数法获得的温跃层强度偏大。因此,对本研究海域来说,当水深≤200m时,采用拟阶梯函数法,当水深〉200m时采用垂向梯度法,最小判定标准统一采用0．05℃／m,可以有效避免陆架坡折海域的水平不连续问题,与实际水文廓线符合较好。     

黄海、东海上空春季气溶胶光学特性观测分析

2003年春季国家卫星海洋应用中心等几家单位在黄海和东海海区进行了为期40 d的二类水体信息测量试验,试验中使用手持太阳辐射计对海区上空大气光学特性进行了观测,并获得了大量晴空天气条件下的大气光学数据.利用本次试验获取的测量数据得到了黄海、东海海区春季的大气气溶胶光学特性,其中包括气溶胶光学厚度和气溶胶粒子谱分布.采用Langley方法对测量得到的太阳直射辐射量进行处理得到了海区上空气溶胶光学厚度,利用得到的气溶胶光学厚度来反演气溶胶粒子谱分布.反演结果表明无云情况下黄海、东海上空的气溶胶光学厚度在0.2~0.4左右,且气溶胶粒子谱分布的变化趋势也很接近;海区上空霾层较厚时测量得到的气溶胶光学厚度明显增大,最大接近0.8;气溶胶粒子谱分布的变化趋势发生了明显的变化.     

The circulation in the southern Huanghai Sea and northern East China Sea in June 1999

On the basis of hydrographic data and current measurement (the mooring system, vessel-mounted ADCP and toward ADCP) data obtained in June 1999, the circulations in the southern Huang-hai Sea (HS) and northern East China Sea (ECS) are computed by using the modified inverse method. The Kuroshio flows northeastward through eastern part of the investigated region and has the main core at Section PN, a northward flow at the easternmost part of Section PN, a weaker anti-cyclonic eddy between these two northward flows, and a weak cyclonic eddy at the western part of Section PN. The above current structure is one type of the current structures at Section PN in ECS. The net northward volume transport (VT) of the Kuroshio and the offshore branch of Taiwan Warm Current (TWCOB) through Section PN is about 26.2×106m3/s in June 1999. The VT of the inshore branch of Taiwan Warm Current (TWCIB) through the investigated region is about 0.4×106m3/s. The Taiwan Warm Current (TWC) has much effect on the currents over the     

Thermal fronts and cross-frontal heat flux in the southern Huanghai Sea and the East China Sea

Synoptic features in/around thermal fronts and cross-frontal heat fluxes in the southern Huanghai./Yellow Sea and East China Sea （HES） were examined using the data collected from four airborne expendable bathythermograph surveys with horizontal approxmately 35 km and vertical 1 m（from the surface to 400 m deep） spacings. Since the fronts are strongly affected by HES current system, the synoptic thermal features in/around them represent the interaction of currents with surrounding water masses. These features can not be obtained from climatological data. The identified thermal features are listed as follows ： （ 1 ） multiple boundaries of cold water, asymmetric thermocline intrusion, locally-split front by homogeneous water of approxmately 18 ℃, and mergence of the front by the Taiwan Warm Current in/around summertime southern Cheju - Changjiang/Yangtze front and Tsushima front; （2） springtime frontal eddy-like feature around Tsushima front; （3） year-round cyclonic meandering and summertime temperature-inversion at the bottom of the surface mixed layer in Cheju - Tsushima front; and （4） multistructure of Kuroshio front. In the Kuroshio front the mean variance of vertical temperature gradient is an order of degree smaller than that in other HES fronts. The southern Cheju- Changjiang front and Cheju -Tsushima front are connected with each other in the summer with comparable cross-frontal temperature gradient. However, cross-frontal heat flux and lateral eddy diffusivity are stronger in the southern Cheju - Changjiang front. The cross-frontal heat exchange is the largest in the mixing zone between the modified Huanghai Sea bottom cold water and the Tsushima Warm Current, which is attributable to enhanced thermocline intrusions.     

黄、东海温盐跃层的分布特征及其季节变化

利用“中韩水循环动力学合作研究”和“中国近海海洋环境综合调查”( 1 996年 4月 -1 999年 1月 )期间各季节 1 2 8°E以西的校正后的 CTD现场水文调查资料 ,对黄、东海温、盐跃层在 4个不同时期 (成长、强盛、消衰和无跃期 )的各特征值的分布特性及其季节变化作了探讨和分析。结果表明 :( 1 )黄海底层显著冷水团的存在 ,使黄海以温跃层占绝对主导地位 ;东海的沿岸海区因受长江径流的影响则以盐跃层为主导。 ( 2 )温跃层的强度主要取决于与其相联的上、下层水团的强弱。冷水团的存在是产生强跃层的根本原因。( 3)夏季东海区双温跃层从浙江近海到济州岛以南水域连成片 ,其分布范围恰好与冬季入侵陆架的黑潮水相一致。 ( 4 )长江冲淡水舌状盐跃层强度等值线在各季节的伸展情况反映了长江冲淡水在各季节的扩散情况 ,一年当中 ,其轴向先从南往北转 ,再从北往南转。 ( 5 )苏北浅滩以及台湾海峡北部终年为无跃区     

东海、黄海浮游植物生物量的粒级结构及时空分布

浮游植物是海洋初级生产力的主要贡献者,初级生产过程是碳的生物地球化学循环的基础,它启动了海洋生态系统的能量流和物质流,支持着大量的渔业生产量.不仅如此,通过复杂的反馈机制,这一过程还对全球气候变化系统产生深远影响.沿岸海域只占全球海洋面积的8%,但却提供了26%的全球生物生产量和2/3到3/4的世界渔业产量.因此,许多重大的国际研究计划,如海岸带陆海相互作用(LOICZ)、全球海洋生态系统动力学研究(GLO-BEC)等,都将近海浮游植物研究作为非常重要的课题.     

Three-dimensional calculations of the currents in the Huanghai Sea and East China Sea during June of 1999

Based on the wind and hydrographic data obtained by R/V Xiangyanghong 14 duringJune of 1999, the currents in the Huanghai Sea and East China Sea are computed by the three dimen-sional non-linear diagnostic, semidiagnostic models and prognostic in the σ coordinate. The computed re-sults show that the density and velocity fields and so on have been adjusted when time is about 3 days,namely the solution of semidiagnostic calculation is obtained. In the northwest part of the computed re-gion, the Huanghai coastal current flows southeastward, and then it flows out the computed region southof Cheju Island. In the west side of the southern part of the computed region, there is other current,which is mainly inshore branch of Taiwan Warm Current, and it flows cyclonically and turns to thenortheast. In the region north of the above two currents, there is a cyclonic eddy southwest of Cheju Is-land, and it has characteristics of high density and low temperature. There is an offshore branch of Tai-wan Warm Current in the west side of the Kuroshio, and it makes a cyclonic meander, then flows north-eastward. The Kuroshio in the East China Sea is stronger, and flows northeastward. Its maximum hori-zontal velocity is 108.5 cm/s at the sea surface, which is located at the northern boundary, and it is106.1 cm/s at 30 m level, 102.2 cm/s at 75 m level and 85.1 cm/s at 200 m level, respectively, whichare all located at the southern boundary. Comparing the results of diagnostic calculation with those ofsemidiagnostic and prognostic calculations indicates that the horizontal velocity field agrees qualitatively,and there is a little difference between them in quantity. The comparison between the computed veloci-ties and the obeered velocities at the mooring station show that they agree each other.     

A study on suspended matters in the South Huanghai Sea in summer time

A joint investigation of marine geoloy in the South Huanshai Sea was carried out by the Institute of Oceanology, Academia Sinica, and the Woods Hole Oceanographic Institution, USA during 1983～1984. This paper reports the investigation results of the suspended matters in the water column at 55 stations in July, 1984 (summer time). The highest concentration region where the value is less than 0.5 mg/L, is found in the central part of the study area and the southern part of Shandong Peninsula. The Taiwan Warm Current which might obstruct the discharge of the Changjiang River to the east of the sea, appears in the distribution of the suspended matters outside the Changjiang River Estuary. Although lots of materials are brought into the sea during the high flow period of the Huanghe and the Chansjiang Rivers in July, this does not form the main scarce of the suspended matters. The main source is the resuspension of depesits. The materials brought by rivers come the second, and biogeneons components in the sea co     

The statistic inversion algorithms of water constituents for the Huanghai Sea and the East China Sea

A group of statistical algorithms are proposed for the inversion of the three major components of Case-Ⅱ waters in the coastal area of the Huanghai Sea and the East China Sea. The algorithms are based on the in situ data collected in the spring of 2003 with strict quality assurance according to NASA ocean bio-optic protocols. These algorithms are the first ones with quantitative confidence that can be applied for the area. The average relative error of the inversed and in situ measured components‘ concentrations are: Chl-a about 37%, total suspended matter (TSM) about 25%, respectively. This preliminary result is quite satisfactory for Case-Ⅱ waters, although some aspects in the model need further study. The sensitivity of the input error of 5% to remote sensing reflectance (Rrs) is also analyzed and it shows the algorithms are quite stable. The algorithms show a large difference with Tassan‘s local SeaWiFS algorithms for different waters, except for the Chl-a algorithm.     

东海、黄海底层鱼类数量分布季节变化的因子分析

根据2000年春(4月)、夏(6月)、秋(9月)、冬(12月)四季东海、黄海底拖网鱼类资源调查资料,使用因子分析的方法分析了该海域鱼类数量分布的季节变化特征。R型分析发现,春季关系最密切的鱼种有4种:斑鳐、凤鲚、海鳗和黑鳃梅童鱼;夏季有5种:鳀、小黄鱼、黄鮟鱇、绿鳍鱼和长蛇鲻;秋季也有5种:带鱼、灰鲳、虻鲉、日本鲭和小黄鱼;冬季有3种:带鱼、鳄齿鱼和发光鲷。历史资源调查证实,夏季的这5个鱼种之间以摄食与被摄食关系为主。进一步分析发现,各季节关系密切的鱼种所聚集分布的水域,正是这些鱼种各季对应的生理周期洄游分布的主要水域。根据Q型分析可以得到各季的综合优势鱼种及其优势分布水域,发现带鱼和小黄鱼是东海、黄海渔业资源的绝对优势鱼种,除了带鱼、小黄鱼以外,其他的综合优势鱼种都是一些价值较低的、生长速度较快的小型鱼类。