The planar photosynthetically available radiation (PAR),turbidity and concentration of chlorophyll a (chl a),were measured at 26 stations in the Huanghai (Yellow) Sea during a cruise of China SOLAS from 19 to 27 March 2005.Due to low chl a (<0.35 mg·m^-3) in upper layers (above 5 m),suspended particulate matter became the major factor that influenced the turbidity in early spring.The calculated vertical diffuse attenuation coefficient of PAR,K_PAR,varied with water depths with a maximum value in the upper 5 m layer.The mean K_PAR in survey area was 0.277±0.07 m^-1 that is considerably higher than most of the other case 2 waters.Within the survey area,K_PAR also showed distinct regional characteristics,corresponding to the distribution of turbidity.Based on measurements,the relationship between K_PAR and turbidity as well as chl a was established.It was suggested that suspended particulate matter plays an important role in light attenuation in the Huanghai (Yellow) Sea in spring.

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/dm³, 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.

为研究珠江口悬浮泥沙输运动力机制，本文发展了一套三维波、流、泥沙耦合数值模型。模型结果与观测数据吻合较好，统计显示模型获得良好的评分分值。利用数值模拟研究了不同强迫（径流，波浪和风）对珠江口中悬浮泥沙的影响。模型结果表明，河口重力环流对珠江口最大浑浊带的发展起着重要作用，特别是在小潮期间。另外，径流的增加可导致泥沙向海输运。底部的悬浮泥沙浓度随着波浪底部轨迹速度和波高的增大而增加。由于西滩水深较浅，波浪对西滩悬浮泥沙的影响大于东槽。西南风引起的波浪对悬沙的影响大于东北风引起的波浪的影响，而东北风致流对悬沙的影响略大于对西南风致流的影响。在其他条件相同情况下，稳定的西南风比稳定的东北风更有利于伶仃洋悬浮泥沙浓度的增加；在稳定的西南风下，伶仃洋平均悬浮泥沙浓度约为稳定东北风下的1.1倍。

Sediment convergence and resuspension are the two major mechanisms in forming turbidity maximum (TM) in the Changfang Estuary.Sediment convergence is mainly controlled by the interaction between runoff and tidal current, the mixing of freshwater and salt water, the former forming tidal TM, whereas the latter forming brackish TM.The TM in the Changjiang Estuary is characterized by a combination of tidal TM and brackish TM, which varies temporally and spatially.

Here, we report the results of high-resolution nitrate measurements using an optical nitrate profiler (in situ ultraviolet spectrophotometer, ISUS) along transect across a high-turbidity shelf (East China Sea) and a low-turbidity shelf (Chukchi Sea). The ISUS-measured nitrate concentrations closely reproduced the results measured by conventional bottle methods in low-turbidity waters. However, for high-turbidity waters of the East China Sea (salinity<30), a correction factor of 1.19 was required to match the standard bottle measurements. The high-resolution ISUS data revealed subtle spatial variability (e.g., a subsurface nitrate minimum) that may have been missed if based solely on bottle results. Four main structures of the nitracline on the East China Sea are apparent from the ISUS nitrate profile. High-resolution nitrate data are important for studying nitrate budgets and nutrient dynamics on continental shelves.

On the basis of the time series of AVHRR data from NOAA satellites and the geographical information system PURSIS, fluctuations of the plume front and the turbidity maximum in the Hangzhou Bay, reflected by the distributions of temperature and suspended sediment concentration respectively, are studied in view of long-term behaviors or seasonal and tidal cycles. The data suggest that the effect of front plays an important role in the development of the turbidity maximum close to the Changjiang Estuary > while the effect of tide dominates over the development of another very turbid water situated in the shoal areas in the southern Hangzhou Bay.

应用Delft3D研究了珠江口最大浑浊带的分布以及影响因素。盐度和悬沙浓度的垂向分布揭示出最大浑浊带范围的变化。最大浑浊带在干季的悬沙浓度比湿季更大，而其中心位置与湿季相比向上游移动10 km。最大浑浊带的形成受到潮汐、径流和地形的综合影响，而沉积物的再悬浮和垂向环流为影响最大浑浊带的主要因素。

Distributions and sources of total organic carbon(TOC)in seabed sediments and their implications for hydrodynamics are analyzed, in the turbidity maximum of the Changjiang Estuary. Ecology ecoenvironmental effects of estuary water on the continuously increasing terrigenous organic carbon from the Changjiang River are also explored through variations of organic carbon content and water quality indicators. Results show that, hydrodynamics exert important influences on distributions of organic carbon in the turbidity maximum of Changjiang Estuary. For their redistribution effect of terrigenous organic carbon within the moving layer in the whole region, variations from land to sea are not indicated by surficial and vertical average values of TOC and total nitrogen (TN) contents in core sediment, as well as organic stable carbon isotopes in surface sediments. However, on the long-time scale, the trend of terrigenous organic carbon decreasing from land to sea is still displayed by variations of stable carbon isotopic average values becoming heavier from land to sea. Previous studies have shown that high content of Chl a cannot appear in the Changjiang Estuary in despite of adequate nourishment supply, because photosynthesis of phytoplankton is constrained by high suspended sediment concentration(SSC). However, an area with a high content of Chl a occurs, which may be caused by resuspended benthic algae with bottom fine grain-size sediments. Tremendous pressures are imposed on the environment of Changjiang Estuary, because of ultrophication trends and special hydrodynamics. Phytoplankton bloom area tends to extend from the outer sea to the mouth of Changjiang River.

浊流是湖泊和海洋中沉积物搬运的主要方式之一,尤其是它形成了世界上众多的作为深水油气田储层的深海碎屑沉积体.最近在南海西北部琼东南盆地的几口钻井已经表明,该盆地发育了大量浊流沉积,而且它们都可能成为优质储层.但是,目前关于这些浊流沉积的来源却存在有很多争论.因此,与评价这些浊积体储层质量同样重要的是要阐明其沉积来源.由于浊流沉积规模巨大,对其进行直接研究较为困难,近些年发展起来的数值模拟技术使得对浊流形成过程的数值模拟研究成为了可能.本研究在基于三维地震资料对浊积体的精细解释基础上,对琼东南盆地西部有钻井约束的地震剖面进行了回剥法恢复其古地貌,并据此建立了数值模拟模型.然后在定义了粒度、初始流速、沉积物浊度等初始边界条件后,通过数值模拟软件ANSYS FLUENT正演模拟了浊流的内部结构和其流体动力学过程,并将模拟结果所产生的浊积体几何形态与其地震反射特征进行对比,讨论其潜在的沉积来源和具体沉积过程.模拟结果表明,经钻井A钻遇的浊积体距离其物源区相对较远,以砂质沉积构成为主.综合考虑所模拟的地震测线位置和方位,对比模拟结果与钻井A的实钻岩性表明,钻井A所钻遇的浊积体来源于越南而不是海南岛.该结果也得到了基于钻井和地震剖面所得出的沉积相平面分布特征的证实.该浊积体物源的确定必将对评价琼东南盆地深水区广泛分布的海底扇的油气勘探潜力具有重要意义.

通过分析长江口最大浑浊带潮周期内定点采集的悬浮物重金属Zn、Pb、Cd、Co和Ni的含量,研究了潮周期内悬浮物重金属含量分布特征和通量及其影响因素。结果表明:5种重金属潮周期内含量均值的大小顺序为:Zn> Ni> Pb> Co> > Cd。潮周期内重金属含量分布特征为:落潮平均含量高于涨潮平均含量;近岸11号站,受附近垃圾处理场污染物排放的影响, Zn和Ni涨潮平均含量高于落潮平均含量;远岸10号站,受海源物质的影响, Cd涨潮平均含量高于落潮平均含量。潮周期内,悬浮物携带的5种重金属主要向东北偏东方向输运,主要为陆源,大部分随悬浮物沉降在11-10号之间的区域。受海源物质的影响,悬浮物中的Cd通量变化相对较小,且输运方向受涨潮流的影响而改为西北向。重金属来源、水体盐度、悬浮物浓度是影响潮周期内悬浮物重金属含量分布的主要因素。Zn、Pb、Co和Ni的含量与海水盐度成正相关,与悬浮物浓度成负相关。受海源物质的影响,Cd的含量与海水盐度和悬浮物浓度的相关性不明显。