Peaked abundance of Calanus sinicus earlier shifted in the Changjiang River (Yangtze River) Estuary: a comparable study between 1959, 2002 and 2005

The sea surface temperature (SST) of the East China Sea (ECS) increased in the past decades,which may have a great impact on the ecosystem of the ECS,including the changes in plankton-population structure.In this paper,the changes in peaked abundance of Calanus sinicus in the Changjiang River (Yangtze River) Estuary were compared between 1959 and 2002,based on the data collected from the seasonally oceanographic cruises and those performed in spring of 2005.It was much higher in spring compared with that in other seasons both in 1959 and 2002.Furthermore,in spring 2005,the time for occurrence and decrease of the peaked C.sinicus abundance advanced about one month, accompanying the increase in the sea surface water temperature (SST).It peaked in June and decreased in July in 1959,however,in 2005,it peaked in May and attenuated sharply in early June.The earlier decrease of peaked C.sinicus abundance may further deteriorate the ecosystem in the Changjiang River Estuary and north nearshore of the ECS.     

长江口水下三角洲泥质区近期沉积物粒度变化特征及其影响因素

河口水下三角洲是河流和海洋环境共同作用的产物,沉积地层中蕴藏了许多环境变化信息.在长江口水下三角洲泥质区采集了柱样SC09,首先利用放射性同位素210Pb确定了沉积柱样的平均沉积速率,其次对沉积柱样以0.2 cm间隔进行高分辨率取样,获得了沉积物粒度参数,然后提取了沉积物粒度敏感组分,并对其进行了经验模态分解(EMD)...     

近20年来长江口表层悬沙分布的遥感监测

利用近20年来长江口地区的美国陆地卫星Landsat TM和ETM影像反演得到了长江口海区表层悬沙分布遥感解译系列图,讨论了长江口表层悬沙的空间分布特征、潮汐变化对泥沙分布的影响、三峡工程对泥沙分布的影响及河口径流量和输沙量对泥沙分布的影响等;描述了长江口海区洪枯季的表层悬沙扩散外界和高浑浊水域范围的变化趋势,并分析了...     

夏季长江口浮游细菌和浮游病毒的分布特征及环境制约因素

应用荧光显微直接计数法,研究了2006年夏季长江口及邻近海域浮游细菌、浮游病毒数量的分布特征,探讨了它们与环境因子之间的关系.结果表明:(1)浮游细菌数量为(6.92×105～5.54×106)个/mL,浮游病毒数量为(2.22×106～9.97×107)个/mL.浮游细菌和浮游病毒数量的平面分布特征较一致,均为近海过...     

秋季长江口北支表层海水pCO2变化特征

根据2009年9月首次获得的长江口北支海水pCO2实测数据,结合温度、盐度等参数,对长江口北支海水pCO2时空分布、变化特征及其影响因素进行了研究.研究结果表明,长江口北支海水pCO2总体呈现出淡水端高,咸水端低的特点;在同等盐度条件下,长江口北支海水pCO2明显高于长江口南支;长江口北支南段海水pCO2与盐度之间有着...     

长江口及邻近海域表层水体溶解氧饱和度的季节变化和特征

根据“908”ST04区块调查的夏、冬、春、秋季四个航次和“908”补充调查的8月航次资料对长江口及邻近海区表层水体溶解氧及其饱和度进行了探讨.研究表明东海北部表层水体在夏季和春季以浮游植物光合作用为主要控制过程,特别是7、8月份长江口外、杭州湾外及浙江近海存在大范围的强光合作用区;秋季以有机质氧化分解过程为主,表层溶...     

长江口跨越锋面颗粒磷季节分布变化特征及影响因素

根据2006年夏、冬季以及2007年春、秋季“海监49号”科学考察船的调查数据,分析了长江口跨越锋面区域(31.00°～31.78°N、121.04°～123.99°E)颗粒总磷(PP),颗粒无机磷(PIP),颗粒有机磷(POP)的季节变化和空间分布特征.结果表明,PIP是水体颗粒磷的主要存在形式;受长江径流输沙量的影...     

Effect of reclamation time and land use on soil properties in Changjiang River Estuary,China

The objective of this study is to analyze soil physical and chemical properties,soil comprehensive functions and impact factors after different years of reclamation.Based on the survey data taken from 216 soil sampling points in the Fengxian Reclamation Area of the Changjiang (Yangtze) River Estuary,China in April 2009 and remotely sensed TM data in 2006,while by virtue of multivariate analysis of variance (MANOVA),geo-statistical analysis (GA),prin-cipal component analysis (PCA) and canonical correspondence analysis (CCA),it was concluded that:1) With the in-crease in reclamation time,soil moisture,soil salinity,soil electric conductivity and soil particle size tended to decline,yet soil organic matter tended to increase.Soil available phosphorous tended to increase in the early reclamation period,yet it tended to decline after about 49 years of reclamation.Soil nitrate nitrogen,soil ammonia nitrogen and pH changed slightly in different reclamation years.Soil physical and chemical properties reached a steady state after about 30 years of reclamation.2) According to the results of PCA analysis,the weighted value (0.97 in total) that represents soil nutrient factors (soil nitrate nitrogen,soil organic matter,soil available phosphorous,soil ammonia nitrogen,pH and soil particle size) were higher than the weighted value (0.48 in total) of soil limiting factors (soil salinity,soil elec-tric conductivity and soil moisture).The higher the F value is,the better the soil quality is.3) Different land use types play different roles in the soil function maturity process,with farmlands providing the best contribution.4) Soil physi-cal and chemical properties in the reclamation area were mainly influenced by reclamation time,and then by land use types.The correlation (0.1905) of the composite index of soil function (F) with reclamation time was greater than that with land use types (-0.1161).     

长江三角洲典型稻作区近地层二氧化碳等湍流通量的观测研究

利用1999年和2000年长江三角洲近地层大气与农田生态系统综合观测试验资料，对常熟地区水稻插秧、拔节、抽穗等不同生长期近地层二氧化碳和感热、潜热、动量等湍流通量特征及变化规律进行了初步研究. 研究结果表明, 平均而言在水稻各生长期，近地面为二氧化碳的汇，白天水稻通过光合作用吸收二氧化碳、夜间则放出二氧化碳，抽穗期消耗的二氧化碳要多于拔节和插秧期；近地面为大气的热源，主要以潜热方式加热大气，尤其是在抽穗期，感热与潜热之比仅为0.058；二氧化碳等湍流通量的变化与辐射平衡各分量及气象要素有显著关系.     

Numerical investigation of the control factors driving Zhe-Min Coastal Current

During the northeast monsoon season, Zhe-Min Coastal Current(ZMCC) travels along the Chinese mainland coast and carries fresh, cold, and eutrophic water. ZMCC is significantly important for the hydrodynamic processes and marine ecosystems along its path. Thus, this bottom-trapped plume deserves to be further discussed in terms of the major driving factor, for which different opinions exist. For this purpose, in this study, a high resolution Semi-implicit Cross-scale Hydroscience Integrated Syste...