摘要
根据2009年8月＂908＂项目长江口补充调查总碱度（TAlk）、溶解无机碳（DIC）、pH值、溶解氧（DO）和叶绿素a（Chla）等数据的分析结果显示,长江口及邻近东海海域夏季溶解无机碳（DIC）含量分布范围在1 647.1~2 236.9μmol/dm3之间,平均值为2 031.2μmol/dm3;空间分布为由近岸冲淡水方向向外海逐渐增加;DIC在垂直分布上总体呈现底层水〉次表层水〉表层水,在29.0°N,122.6°E的底层存在1个高值中心,这可能与低温高盐的台湾暖流深层水作用有关。对TAlk、DIC与盐度的相关性探讨发现,当盐度为10~25,TAlk、DIC与盐度呈现很好的保守性关系;而在盐度接近0、大于30及盐度为25~28时则出现偏离保守型稀释曲线现象,而这3个区域分别属于河口淡水端、海水端和长江口羽状锋区域,这一现象的发生与河水端不同的输入源、海水端的水文物理过程以及长江羽状锋区域生物活动强弱密切相关。此外,根据DIC体系中DIC、pH值、温度和盐度等的实测数据进行推算可知,长江口及其邻近海域表层pCO2的范围为15.4~166.9 Pa（154.0~1 669.0μatm）,其中以29.5°N、123°E为中心的区域出现表层pCO2值的低值中心[〈39.0 Pa（390μatm）],理论上可认为是大气CO2的1个典型汇区。
Based on the field survey conducted in August 2009,the total alkalinity（TAlk）,dissolved inorganic carbon（DIC）,pH,dissolved oxygen（DO） and chlorophyll a（Chl a） in Changjiang River Estuary and its adjacent sea areas were analyzed.This area is the most dynamically active zone in East China Sea where high pCO2 riverine water and highly productive coastal water meets.The results indicate that the concentration of DIC in this area is 1 647.1~2 236.9 μmol/dm3,with an average value of 2 031.2 μmol/ dm3;the spatial distribution presents a gradual seawards increasing trend from the nearshore diluted water,and is greatly influenced by the mixing of the river freshwater and seawater;its vertical distribution depends on the depth,with a high value in the bottom water and relatively low value in the surface.A high value center of DIC exists at 29.0°N,122.6°E,which is related to the deep water of low temperature and high salinity of Taiwan warm current.The research on the coherence of TAlk and DIC with salinity shows that when the salinity is 10~25,TAlk and DIC present good conservative relation with salinity,while dilute curve deflected from conservative relation appears when the salinity is approaching 0,30 or 25~28,which belong to estuarine freshwater end,seawater end and plume front zone of the estuary separately.This is closely related to the different inputs from the rivers at the estuarine freshwater end,strong hydrophysical processes at the seawater end and biological activities in the plume front zone.Besides,prediction according to the observed values of DIC,pH,temperature and salinity shows that the value of pCO2 in Changjiang River Estuary and its adjacent sea areas is 15.4~166.9 Pa（154.0~1 669.0 μatm）,with a low value center（390 μatm） at 29.5°N,123°E,which can be referred theoretically to as a typical gathering area of atmospheric CO2.
出处
《海洋学研究》
2011年第3期63-70,共8页
Journal of Marine Sciences
基金
国家科技支撑计划资助项目(2008BAC42B01)
“973”计划资助项目(2010CB428903)
“908”专项资助项目(908-01-BC06、908-ZC-I-03)
国家海洋局第二海洋研究所基本科研业务费专项资助项目(JT0707、JG1022)
