2001年冬春转换期间南海东北部水文和环流特征

根据2001年3月份南海东北部航次调查温、盐资料,分析了2001年冬末春初南海东北部温、盐结构和环流的特征.分析结果表明:观测期间南海东北部环流主要受一次海盆尺度气旋型冷环流支配,冷环流呈现双核结构,垂向尺度接近1000 m.吕宋海峡内侧断面的水交换在600 m以浅海水流入南海,在断面南部(20°N以南)中层和深层有流出,断面法向地转流向西净输运量为6.9×106m3/s;直接的黑潮入侵不超过120.5°E,但有部分的黑潮水沿陆坡达到台湾岛西南部海域,并更有一部分逸入东沙岛以西海域,与南海水混合变性.

Hydrography and circulation characteristics about the northeast area of South China Sea during March 2001

The structures of temperature and salinity and characteristics of current are analyzed by temperature and salinity data received from the cruise of northeast South China Sea(SCS) during late winter-early spring, 2001, combined with SeaWiFs data at the same period.The results indicate that the current is mainly dominated by a sub-basin scale cold cyclonic-gyre.This cold gyre shows double-core structure, and the vertical scale can touch the depth of 1 000 m.Water exchange about the inboard transects of Luzon Strait shows that water enter into SCS above 600 m, and flowout on the south of transect (south of 20×N) at middle and deep layers.The net transport of water from Luzon Strait is about 6.9×10⁶m³/s.And the direct intrusion of Kuroshio cannot exceed 120.5°E.But part of Kuroshio water can arrive at the southwest of Taiwan along shelf, some of which even extend to west of Dongsha Archipelago and change its characteristic by mixing with SCS water.