黑潮化学物质输入东海的途径与通量

在对黑潮水文特征分析的基础上,探讨了黑潮对中国近海化学物质输入途径,归纳总结了黑潮对东海生源要素、痕量元素、同位素及其他化学物质的输入特征,提出了黑潮对中国近海化学物质输入研究应着重关注的问题。主要的结论包括:吕宋海峡、中国台湾东北部及日本九州西南海域是黑潮向中国近海输送化学物质的3个关键区域;黑潮表层水向东海陆架的扩展、次表层水和中层水的涌升以及黑潮季节性流轴摆动是黑潮向东海输送化学物质的基本途径。黑潮主体生源要素的浓度随深度的增加而增大。黑潮对东海生源要素的影响夏季最弱、春季次之、秋冬季最强,其对东海生源要素的输入通量要远高于河流、大气等其他输入源,并且各水层中以中层水的生源要素输入通量为最大。痕量元素在黑潮主体的分布、对东海的输入通量等方面均表现出了与生源要素的差异,各痕量元素的分布及输入通量随痕量元素的不同而不尽相同,其中次表层水的涌升在对邻近海域痕量元素分布的影响中起到了重要作用。同位素可指示黑潮对东海陆架的入侵程度及变化规律,并与营养盐等有一定的相关性。黑潮是东海微量温室气体N2O,CH4等其他化学物质的重要输入源,进而对东海生态环境产生影响。进一步研究应着重从系统性外海观测、痕量元素及同位素等化学物质调查、黑潮对中国近海输入化学物质的控制过程等方面深入开展。

Pathway and Flux of Inputting Chemical Substances from the Kuroshio to the East China Sea

The inputting pathway of chemical substances from the Kuroshio to China Margin seas and inputting characteristics of biogenic elements, trace elements, isotopes and other chemical substances from the Kuroshio to the East China Sea (ECS) were reviewed on the basis of hydrological analysis of the Kuroshio, and some important issues which should be concerned in this research field were put forward in the end. Luzon Strait, Sea off Northeastern Taiwan and Southwestern Kyushu are the critical areas for the Kuroshio input. Extension of the Kuroshio surface water, upwelling of the Kuroshio subsurface water and intermediate water, seasonal axial swing are the basic means for the input of chemical substances. The concentration of biogenic elements in the Kuroshio water increases with depth. For biogenic elements in the ECS, the influence of the Kuroshio is the weakest in summer, then in spring, and strongest in autumn and winter. The influx of biogenic elements from the Kuroshio is higher than other sources like river and atmosphere, and the intermediate water owns the largest share among all layers. The distribution and influx to the ECS of trace elements show difference with biogenic elements, and differ from each other under the impact of the upwelling of Kuroshio subsurface water. Isotopes can indicate the incursion of the Kuroshio and show certain correlation with nutrition. The Kuroshio is also an important source for some green house gas like N₂O, CH₄, which will further affect the ecosystem of the ECS. The future research should focus on systematical offshore observation, investigation of chemical substances like trace elements and isotopes, controlling process of chemical substances input from the Kuroshio to China margin seas.