春季南黄海表层海水中二氧化碳的分布特征及其影响因素

The Distribution and Influencing Factors of Carbon Dioxide in the Surface Seawater of the South Yellow Sea during Spring

根据2007年4月南黄海区块(SYS)表层海水中二氧化碳分压(pCO_2)的连续走航数据,结合水温(T)、盐度(S)、叶绿素(Chla)以及pH的同步观测资料,对该海域pCO_2分布特征及其主要影响因素进行了初步探讨。分析结果表明:春季南黄海pCO_2的范围在365.2~734.9μatm之间,平均值为548.0μatm;最高值出现在121.5°E,33.4°N海域,最低值出现在123°E,32.3°N海域。受海水中物理、化学和生物因素的综合影响,pCO_2的分布存在较大的不均匀性,总体上表现为西部高于东部,中间高于南北两边;在苏北浅滩和鲁南海区,pCO_2与水温的变化呈正相关关系,与盐度的大小呈明显的负相关关系,而在长江入海口变化趋势则相反;此外,在整个调查海区pCO_2与叶绿素、pH基本上呈负相关关系。研究将两台检测器串联进行互校,同时利用二氧化碳标准气体对其中一台仪器进行全程校准,可连续不间断观测海水和大气中的pCO_2。该方法操作简单,获得的数据准确可靠,可为节能减排能力建设提供技术支持。

The partial pressure of carbon dioxide(pCO 2)in the surface seawater of the South Yellow Sea(SYS)was investigated by means of cruising observation during the spring of 2007.The distribution characters and influencing factors of the pCO 2 were studied by combining with the cogredient data of the seawater temperature,salinity,chlorophyll,pH.The results showed that the values of the pCO 2 in the surface seawater of the SYS was in the range of 365.2~734.9μatm,with an average of 548.0μatm,the maximum value appeared in sea area near 121.5°E,33.4°N,and the minimum value appeared insea area near 123°E,32.3°N.As a whole the distribution of the pCO 2 present obvious horizontal inhomogeneity,gradually decreased from west to east,andwas higher at the middle latitude than both sides under the combined influence of biological,hydrological and chemical factors.The pCO 2 was in direct proportion to the seawater temperature and in inverse proportion to the seawater salinity in the shoal-water area along the northern coast of Jiangsu Province and the near shore area of southern Shandong Province,but there was a reverse trend at the mouth of Yangtze River.In addition,there was a negative correlation between the pCO 2 and the chlorophyll as well as between the pCO 2 and the pH value in the whole investigated sea area.In this study,it was the first time thatone of two CO 2 analyzers was calibrated by series-connecting one of the channels,meanwhile,the other analyzer was calibrated with the standard gas of carbon dioxide through the other channel.Therefore,the concentrations of carbon dioxide in air and seawater could be continuously monitored.It was proved that themethod was simple to operate,and the data obtained were accurate and reliable,with the hope of providing technical support for capacity building on energy conservation and emission reduction.