东亚地区沙尘气溶胶的源和汇

RESEARCH ON SOURCE AND SINK OF EAST ASIA'S SAND-DUST AEROSOLS

从沙尘气溶胶的源地、输送及清除等几方面 ,讨论了沙尘天气发生的基本条件 ,即强风、大尺度环流形势和中尺度天气系统。论述了东亚沙尘气溶胶的源和汇及其输送过程 ,并初步探讨了沙尘气溶胶沉降入海及其对海洋生态系统的可能影响。东亚沙尘气溶胶的源地主要集中在新疆、甘肃和内蒙的沙漠地带 ,中国北部每年输入大气的沙尘气溶胶总量约为 43× 1 0 6 T。中国西北地区每年向海洋的黄沙输送量约为 1 0 6～ 1 0 7T,通过干、湿沉降入海的沙尘气溶胶对海洋的初级生产有促进作用或与藻类的爆发性繁殖有关 ,入海的气溶胶还含有多种污染成分 ,从而可能对海洋生物和生态系统产生损害。

This paper aims to make a discussion and analysis of the sand dust aerosols, their origin and their propagation and sinking process. As we know, sand dust storm is a kind of natural disaster with serious detrimental effect in the arid and semi arid areas. They usually break out in the specific climatic conditions with strong wind, large sphere meteorological circulation system and the related mesoscale synoptic system. Such dust aerosols, when brought into the high altitude of the air and blown with the wind, may fall over the land as well as onto the ocean surface, which may have possible effect on the oceanic eco system. The source areas of the East Asian sand dust aerosols are mainly located in the deserts of Gansu, Xinjiang, and Inner Mongolia with the total amount of dust aerosols emitted from China's north at about 43×10 6 t per year. And the dust aerosols from the China's northwest with the total amount of dust aerosols working out at about 10 6 10 7 tons annually are found to be blown into and sink widely in the north of China and transmitted so far as to Hong Kong and Taiwan areas. Korea, Japan and even the North America can also be influenced by some particularly strong dust storms. Our investigation shows that the large amount of dust aerosols blown onto the sea through dry and wet deposition may probably increase the primary production and cause blooms in marine systems. On the other hand, the harmful components, such as heavy metals, PAH and PCB in the dust aerosols may exert baneful effect on halobios and marine ecosystems.