2006年9月南海北部表层温盐场的走航观测

Underway observation of surface temperature and salinity in north South China Sea in September 2006

通过2006年9月南海北部开放航次的走航观测,得到了该海区多个断面的表层温度、盐度分布曲线。QuikScat海面风场资料显示观测期间处于西南季风向东北季风的转换阶段,走航观测所得的温、盐资料显示出在这一季风转换的特殊阶段该海区表层的水文特征。珠江口冲淡水的扩散范围在季风转向前后有显著的变化,低盐的冲淡水在西南季风阶段向珠江口外海区的东南方延伸较远,而在东北季风阶段则受珠江径流量、南海北部表层环流等因素的影响收缩至珠江口附近。闽南近岸和台湾浅滩南部表层具有低温高盐特征,但CTD资料表明台湾浅滩区域存在上升流,结合风场资料,可证实观测期间此处的上升流由海流-地形因素所造成。

Based on the underway observation data of Joint Survey of Northern South China Sea in September 2006, the distributions of surface temperature and salinity along several sections were obtained. The sea surface wind field data from QuikScat indicated that September was the conversion period from southwest wind to northeast wind in 2006, and the temperature and salinity data obtained from the underway observation could give a clear demonstration of the hydrological character of the northern South China Sea during this special period. The extension of diluted water near the estuary of Zhujiang River had a major change after the monsoon conversion. During the phase of southwest monsoon, the diluted water could extend to the southeast to a larger distance; while the diluted water was confined to the nearby area of the estuary in the northeast monsoon. In the inshore area off south Fujian and southern part of Taiwan Bank there existed cold and high salinity waters. It was proved by the CTD data that an upwelling was active in the southern part of Taiwan Bank. Considering the northeast monsoon, it could be confirmed that this up- welling was driven by the current-topography effect.