摘要
在这项综合性海洋调查中，设置海水pH这个观测项目的目的是：<1>为海洋生物学、海洋沉积学和海洋化学等各海洋分支学科的研究提供参考资料；<2>结合海水总碱度调查资料对海水碳酸盐体系进行研究。海水pH的测定基本上按“海洋调查规范”推荐的方法进行，使用的仪器和具体操作步骤已在第一章第二节中作了介绍。由于测定结果的精密度较好，加上调查范围广，时间长，pH的时空分布有某些明显的规律和特点，因此需要对海水pH的时空分布及其与海洋环境的关系进行描述和讨论。
In this section, the time and space distribution of pH are describedand the mechanism causing the change in pH are discussed preliminarily.The maximum pH values, 8,49, were observed in the oceanic surface water at Sta.E1 and E2 near the Changjiang River mouth where the presence of a large phytoplankton biomass were observed and the waters were nutrients-rich and supersaturated with respect to DO. The pH values were less 8.0 under the depth of 800m in the southeast boundary of the observed zone where the saturation of DO was less than 34%, but the nutrient concentrations were higher than in the upper layers.In general, the pH values were higher in the surface water, in somewhere, a maximum layer of both of pH and 02 would occured simultaneously above the thermocline. The change in temperature is likely signifisent for the distribution of pH, and the pH values did not increase with the decrease of temperature, but increased. In most cases, between the pH and DO or pH and 02%, especielly later ,were positiely correlated. The change in pH of sea water were controlled largely by Mogeochemistry processes-photosynthesis in surface water and the decomposition of organism under the photosynthetic layer.
