Seasonal and annual variations of marine sinking particulate flux during 1993~1996 in the central South China Sea

A total of 67 samples from the upper and lower sediment traps in the central South China Sea were analyzed, which were collected during 1993~1996. It is indicated that the distribution of stable isotope values, surface primary productivity, fluxes of total particulate matter, carbonate, biogenic opal, organic carbon, planktonic foraminiferal species and their total amount exhibit obviously seasonal and annual fluctuations. High values of the fluxes occurred in the prevailing periods of the northeastern and southwestern monsoons, and the low values occurred during the periods between the two monsoons. The fluxes of some planktonic foraminiferal species (Globigerinoides sacculifer, G. ruber, Globigerinita glutinata, Neogloboquadrina dutertrei) and their percentages also exhibit two prominent peaks during the prevailing periods of the northeastern and southwestern monsoons respectively, while those of Globigerina bulloides, Globorotalia menardii and Pulleniatina obliquiloculata only exhibit one peak in the prevailing periods of the northeastern monsoon. In addition, fluxes and percentages of Globigerinoides sacculifer and Globorotalia menardii as well as the fluxes of carbonate and total amount of planktonic foraminifera decrease gradually from 1993 to 1996, and those of Globigerina bulloides, Globigerinita glutinata and biogenic opal increase gradually from 1993 to 1996. The fluxes of carbonate and organic carbon in the upper trap are higher than those in the lower one. The study indicates that the seasonal and annual variations of the sediment fluxes and planktonic foraminiferal species are mainly controlled by the changes of surface primary productivity and hydrological conditions related to the East Asian monsoon. The lower carbonate and organic carbon fluxes in the lower trap are related to the dissolution.     

南海上层环流观测研究进展

回顾了近50a来南海环流研究的进展，重点介绍了近期有关南海上层总环流的观测研究成果，并就南海季风急流、南海暖流、南海南部的次海盆尺度环流，以及南海东北部环流的几个问题进行了专门讨论。     

南海西北部表层沉积物常量元素地球化学特征

分析了南海西北部198个表层沉积物的常量元素地球化学特征,研究了沉积物常量元素的含量分布特征、富集程度和粒度效应。结果显示,沉积物的常量元素以SiO2、Al2O3、CaO含量较高,平均值分别为45.9%、8.53%、16.7%,其中SiO2、Al2O3代表了陆源碎屑组分,CaO代表了生物碎屑组分。陆架区具有较高的SiO2含量,陆坡区具有较高的Al2O3、CaO含量,但是,Al2O3的高含量在深水下陆坡区,而CaO的高含量在上陆坡岛礁区。总体上,常量元素Fe2O3、K2O、MgO、Na2O、TiO2与Al2O3具有相似的含量分布特征,指示细粒组分的吸附作用;而SiO2、CaO与Al2O3呈相反的分布特征以及负相关关系,反映了沉积物的常量元素受到石英矿物和碳酸盐矿物的稀释作用。大部分元素的富集因子介于1~2之间,富集特征不明显,表明碎屑物质主要为地壳来源,仅CaO、MnO出现较高的富集因子,指示陆坡区生物富集作用和深水陆坡区化学沉积作用的贡献。     

TRMM-retrieved Cloud Structure and Evolution of MCSs over the Northern South China Sea and Impacts of CAPE and Vertical Wind Shear

Cloud structure and evolution of Mesoscale Convective Systems(MCSs) retrieved from the Tropical Rainfall Measuring Mission Microwave Imager(TRMM TMI) and Precipitation Radar(PR) were investigated and compared with some pioneer studies based on soundings and models over the northern South China Sea(SCS).The impacts of Convective Available Potential Energy(CAPE) and environmental vertical wind shear on MCSs were also explored.The main features of MCSs over the SCS were captured well by both TRMM PR and TMI.However,the PR-retrieved surface rainfall in May was less than that in June,and the reverse for TMI.TRMM-retrieved rainfall amounts were generally consistent with those estimated from sounding and models.However,rainfall amounts from sounding-based and PR-based estimates were relatively higher than those retrieved from TRMM-TMI data.The Weather Research and Forecasting(WRF) modeling simulation underestimated the maximum rain rate by 22% compared to that derived from TRMM-PR,and underestimated mean rainfall by 10.4% compared to the TRMM-TMI estimate,and by 12.5% compared to the sounding-based estimate.The warm microphysical processes modeled from both the WRF and the Goddard Cumulus Ensemble(GCE) models were quite close to those based on TMI,but the ice water contents in the models were relatively less compared to that derived from TMI.The CAPE and wind shear induced by the monsoon circulation were found to play critical roles in maintaining and developing the intense convective clouds over SCS.The latent heating rate increased more than twofold during the monsoon period and provided favorable conditions for the upward transportation of energy from the ocean,giving rise to the possibility of inducing large-scale interactions.     

东海陆架盆地南部区域地震速度分析

在利用速度谱资料进行速度研究的可行性基础上,使用多种方法对速度谱资料进行甄别、筛选,对有效的速度谱资料进行统计、分析,计算出瓯江、闽江、基隆、晋江4个区域及全区的平均速度趋势,阐明了制作各反射层位平均速度分布图的方法,为本区时深转换提供基础资料。同时,分析了地震地质构造与速度趋势的相关性和一致性,对盆地内构造活动不强的区域等速度线与地层分布趋势及密度的关系进行了探讨,指出其对研究重力资料有一定的指导作用。     

中国东海区海洋倾废管理现状与对策

实现对海洋倾废科学有效管理是保护海洋环境及海洋资源的一项重要内容和主要任务.东海作为我国海洋生产力最大的海区,近年来,随着海洋事业和沿海区域经济的发展,向海上倾倒废弃物的数量和规模都在不断增加.在实际海洋倾倒过程中存在着倾倒区选划利用不合理、违法违规倾倒和执法监管不力等问题,直接影响着东海海洋生态环境平衡与可持续发展.因此,在对1999-2010年东海区海洋倾废活动现状进行全面客观梳理的基础上,就倾倒行为存在的主要问题进行实证分析,并结合东海区沿岸省市海洋发展的情况与对海洋倾倒的实际需求,为实现对海洋倾废合理有效的管理,保护海洋生态环境提出切实可行的对策.     

Methane fluxes and gas hydrates as well as seismic activity in the Okhotsk Sea

The research works of methane concentration in water column of the Okhotsk Sea from 1984 to 2005 were reviewed. And some regularities of methane distribution in water column in the North-East Sakhalin slope of the Okhotsk Sea were concluded.     

渤海湾北部滨外沙坝演变的遥感分析

通过多时相航空遥感影像和MSS、TM、ETM卫星遥感影像的解译、对比,分析渤海湾北部滨外沙坝近50年来的演变过程。结果表明:在波浪、潮汐、潮流和河流等动力因素的作用下,滨外沙坝的动态变化较为明显,在整体西向漂移、向海侧边线蚀退的背景下,个体沙坝的变化表现为陆向蚀退、侵蚀消亡、西南向漂移与端点蚀退、西向漂移与端点延展和海向淤进与陆向蚀退交替等多种态势。     

Comparisons of several evaporation/precipitation datasets for the Bohai Sea based on salinity simulation

Evaporation (E) rate and precipitation (P) rate are two significant meteorological elements required in the ocean baroclinic modeling as external forcings. However, there are some uncertainties in the currently used E/P rates datasets, especially in terms of the data quality. In this study, we collected E/P rates data from ERA-40, NCEP/NCAR Reanalysis, HOAPS for the Bohai Sea and nine routine stations around Laizhou Bay, and made comparisons among them. It was found that the differences in E/P rates between land and sea are remarkable, which was due to the difference in underlying surfaces. Therefore, the traditional way of using E/P rates acquired on land directly at sea is not correct. Since no final conclusion has been reached concerning the net water transport between the Bohai Sea and the Yellow Sea, it is unfeasible to judge the adequacy of the four kinds of data by using the water budget equation. However, the E/P rates at ERA-40 sea points were considered to be the optimal in terms of temporal/spatial coverage and resolution for the hindcast of salinity variation in the Bohai Sea. Besides, using the 3-D hydrodynamic model HAMSOM (HAMburg Shelf Ocean Model), we performed numerical experiments with different E/P datasets and found that the E/P rates at sea points from ERA-40 dataset are better than those from NCEP/NCAR Reanalysis dataset. If NCEP/NCAR Reanalysis E/P rates are to be used, they need to be adjusted and tested prior to simulation so that more close-to-reality salinity values can be reproduced.     

Coralligenous habitat in the northern Adriatic Sea: an overview

The rocky outcrops irregularly scattered in the sandy‐muddy sea bed of the Northern Adriatic, formed by a base rock and a superimposed concretion of vegetal and animal organisms, are considered an infralittoral coralligenous habitat, according to the most recent definition. In the last four decades, research has mainly concentrated on their geology because of the question of the origin of the base rock – very similar to beachrock – which has only recently been attributed to sedimentary cementation induced by methane seeps. Studies on their macrobenthic assemblages have also been published recently, but true comparisons among them are difficult because they mostly refer only to a few selected phyla or to short‐term observations. Very few papers deal with the whole of the animal and plant communities, including all taxonomic groups and the most important environmental variables. On the basis of the literature data concerning several outcrops in the Gulf of Venice, we suggest that the Adriatic reefs differ slightly from the classic deeper coralligenous assemblages around the Mediterranean coast because they have smaller concretions of algae builders. We also suggest that the Northern Adriatic coralligenous reefs are younger than the other reefs occurring in the Mediterranean Sea.