秋季长江口北支表层海水pCO2变化特征

摘要

Based on seawater pCO2 measurements obtained for the first-time in the North Branch of Changjiang River Estuary, combined with the temperature, salinity and other parameters, its spatial and temporal distribution, variations and influencing factors were studied. The results show that the seawater pCO2 is generally higher at the fresh water end and lower at the seawater end. The seawater pCO2 of the North Branch is higher than that of the South Branch obviously at the same salinity. There is a good negative correlation between the seawater pCO2 and the salinity in the southern section of the North Branch, indicating that the area is significantly affected by the tide and the change process is mainly controlled by the mixing of salt and fresh water. The seawater pCO2 and salinity in the northern section of the North Branch have the same changing trend, with a net increase of seawater pCO2 in this area, which indicates that it is not only affected by the exchange of salt and fresh water, but also by other factors, such as river input, biological respiration and decomposition of carbonates and so on.%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与盐度之间有着较好的负相关关系,表明该区域受潮汐影响显著,其变化过程主要受咸淡水混合作用控制；长江口北支北段海水pCO2与盐度的变化趋势一致,在该区域内海水pCO2呈现出净增加,表明其除受到咸淡水交换影响外,还可能受外源输入、生物呼吸作用以及碳酸盐分解等过程的影响.