1998年冬春季粤港赤潮爆发海区异常高SST成因分析

Analysis of Abnormally High SST in the Red Tide Sea Areas of Guangdong and Hong Kong in the Winter- Spring of 1998

根据海洋站、气象站的观测资料和历史文献,较系统地分析了1998年冬春季粤港发生大规模赤潮期间广东沿海海表水温(SST)变化特点及异常高SST的原因.结果表明,1997年4月至1998年6月,月平均SST呈准同步变化趋势.赤潮大爆发期间各站的季平均海表水温距平(SSTA)为1.1℃～1.5℃,达到异常高SST标准.其中月平均SSTA达1.5℃～2.O℃.SSTA有两个明显峰期分别出现于1997年12月-1998年1月和1998年4-5月.异常高SST的主要原因是全球气候变暖,受强EI Nino影响、冬季风异常弱、南海高压持续偏强.

This paper systematically analyzed the characteristic of SST change and the reasons for the abnormally high SST in the Guangdong coastal sea area during the large scale red tid eoccurring in Guangdong and Hong Kong in the winter-spring of 1998, based on the observed data provided by ocean stations, observatories and historical documents. From Apr. 1997 to Jun. 1998,the monthly mean SST change trend is quasi-synchronous. During the breakout of red tide, the quarterly mean SSTA of every station is 1.1℃-1.5℃, which is up to the standard of abnormally high SST, and the monthly mean SSTA is 1.5℃-2.0℃. There are two obvious peaks of SSTA happening from Dec. to Jan. and Apr. to May. The main reasons for this abnormally high SST are global warming, strong El Nino, unusually weak winter monsoon and lasting strong South China Sea high pressure.