闽中沿岸上升流特征和成因分析

THE CHARACTERISTICS AND CAUSE ANALYSES OF THE UPWELLING IN THE COASTAL AREA OF CENTRAL FUJIAN

综合分析了前期（１９６３－１９６４年）和近期（１９８３—１９８４年、１９８７—１９８８年）台湾海峡区的温度、盐度、水化学要素和海流等资料，进一步确证了夏季闽中沿岸海域存在的低温、高盐和低溶解氧且不饱和区是深底层海水涌升所造成的。该上升流中心位于海坛岛附近海域，涌升水一般可升至１０ｍ层左右。上升流显现于５月末，７月最盛，衰退于８月末，其分布范围及理化特征具有明显的月际和年际变化。分析表明，该上升流的形成主要是Ｎ向海流和地形的综合效应所导致，但盛行的西南季风亦是一个不可忽视的因素。

This paper analyses the data of temperature, salinity, marine chemical elements and currents during 1963-1964, 1983-1984 and 1987-1988 in Taiwan Strait. It was further verified, that water area with low temperature, high salinity and unsaturated but low dissolved oxygen was formed by bottom water umpwelling in the coastal area of central Fujian in summer. The upwelling center is near Haitan Island, and generally arrives to 10m level. The upwelling forms at the end of May, strengthens in July, and decays after August. There. are obvious monthly and yearly anomalies in the upwelling area with physical and chemical characteristics. The analyses show, that the northwards current (strait warm current)and the surface and bottom cross flow caused by .the influences of topography are the main cause of the upwelling in the coastal area of Central Fujian near Haitan Island. But to the circulation movement of the strait warm current, the prevailing southwest wind is an factor that may not be ignored.