春季长江口及邻近海域水体Eh和pH的分布

发布时间：2018-08-20 15:56

【摘要】：依据2015年春季对长江口及邻近海域水体Eh和pH的现场调查数据,分析研究区海域水体Eh和pH的空间分布特征,结合同航次现场测得的温度、盐度数据,系统探讨了Eh和pH对水团发育特征的指示作用及对自生矿物形成的影响。结果显示:研究区水体为弱氧化环境,Eh变化范围为202.3~317.2mV,空间分布上具有分带性和不均一的特点,表现为近岸高、离岸越远越低,北部垂向混合均匀、南部层化作用明显。该海区水体总体上为中性-弱碱性环境,pH变化范围为7.05~8.19,空间分布上具有分带性,表现为近岸低、外海高,北部层化明显、南部混合均匀。依据pH-Eh判别图解,判定存在3个水团:长江冲淡水团以低pH和高Eh为特征,台湾暖流为高pH和低Eh,而沿岸流水团以快速变化的pH为特征。pH-Eh特征表明研究区水体中有利于铁、锰氧化物(Fe2O3和Mn2O3)等自生矿物的形成,水体中出现的少量胶黄铁矿(FeS2)与微环境有关。
[Abstract]:Based on the field survey data of Eh and pH in the Yangtze Estuary and its adjacent waters in spring of 2015, the spatial distribution characteristics of Eh and pH in the waters of the region were analyzed, and the indicative effects of Eh and pH on the development characteristics of water masses and the formation of authigenic minerals were systematically discussed in combination with the field temperature and salinity data of the same voyage. The water body in this area is a weak oxidizing environment with Eh varying from 202.3 mV to 317.2 mV. The spatial distribution of Eh is zonal and inhomogeneous. It is characterized by high nearshore, lower offshore distance, uniform vertical mixing in the north and obvious stratification in the south. According to the pH-Eh discriminant diagram, there are three water masses: the Yangtze River diluted water mass is characterized by low pH and high Eh, the Taiwan warm current is characterized by high pH and low Eh, and the coastal current mass is characterized by fast changing pH. The formation of authigenic minerals such as compounds (Fe2O3 and Mn2O3) and the presence of a small amount of pyrrhotite (FeS2) in the water are related to the microenvironment.
【作者单位】：中国海洋大学;海底科学与探测技术教育部重点实验室;上海海洋大学海洋科学学院;
【基金】：国家自然科学基金项目——东海内陆架250年来海洋温盐和生产力重建及其对年代际气候波动的响应(41376055) 国家重大基础研究发展计划项目——气候变化影响下典型海岸冲淤过程及演变趋势(2010CB951202)
【分类号】：P734

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