苏北沿岸水的去向与淡水来源估算

WHEREABOUTS AND FRESHWATER ORIGINATION OF THE SUBEI COASTAL WATER

本文基于2006—2007年春、夏、秋、冬季CTD观测的盐度资料分析了苏北沿岸水盐度的季节变化特征,并利用冬、夏季盐度场变化估算了苏北沿岸水的淡水来源。结果表明:冬季苏北沿岸水在东北季风的驱动下顺岸南下,在离开苏北浅滩后转向东南进入东海;夏季低盐的苏北沿岸水分多支向北、向东流出沿岸区,后者汇入南黄海夏季冷水团环流中。估算结果表明苏北沿岸水的淡水来源主要是苏北沿岸的入海径流水,约占总量的65%,次之是降水/蒸发量通量和长江冲淡水沿江苏沿岸的北向扩展。

To understand and estimate whereabouts and freshwater origination of the Subei （North Jiangsu Province） coastal water, we analyzed the CTD salinity data acquired in 2006-2007, and the salinity variation in winter and summer. Results show that in winter, the Subei coastal water flows southward alongshore driven by the northeasterly monsoon, and then turns southeast off the Subei shoal and merges with the East China Sea. In summer, low-salinity coastal water flows away off the Subei coast in three major branches （one northward and two eastward）. The eastward ones mingle with cold-water masses in summer in the southern Yellow Sea. Our estimated result indicates that the freshwater off the Subei coastal water comes mainly from local runoff （taking 65% of the total）, and those from precipitation/evaporation flux and the northward extension of the Changjiang （Yangtze） River plume along the Jiangsu coast are minor contributors.