摘要
利用1987～2005年5～10月的SST资料;2002～2006年5～10月的叶绿素a资料及1992～2006年5～10月的海面风场资料,研究舟山及其邻近海域上升流的长周期变化与海面风矢量对其作用力。SST资料显示,研究海域内的上升流以海表温度下降的形式出现,其季节、年际变化明显;上升流现象年年存在,其与非上升流区的平均温差1.4℃。Chla资料显示,研究海域内上升流区分布着高叶绿素浓度,其范围与SST低温区在位置、时间及形状上大体一致。这些海域的高叶绿素浓度可能与上升流在涌生过程中从底层带到海表面的营养物质有关。风场对上升流作用明显,5～6月、8～9月是风向的南北转变期,风向由北向南转变时,上升流开始出现,反之,上升流逐渐减弱;6月底～8月初,研究海域被西南季风控制着,上升流在这期间最强盛,夏季盛行的西南季风是上升流形成的重要原因。
Data on Sea Surface Temperature derived from NOAA/AVHRR between 1987 and 2005,chloro- phyll-a from 2002 to 2006 and wind vectors from 1992 to 2006 have been used to study the annual variation of the upwelling in the Zhoushan islands and adjacent seas.Satellite observations have revealed that the upwelling zone occurred every year in the study domain during summer months,characterized by distinctly low water temperatures and high Chl a concentrations.The difference of SST among the upwelling and the surrounding waters is about 1.4℃.Chla images derived from MODIS sensor show high Chla concentrations in the up- welling zone,which is coincided with the low SSTS in terms of location,shape,and time.These high Chla concentrations in the upwelling zone may be related to the upwelling waters that bring nutrients from bottom to surface.The wind forcing exerts positive effects on upwelling.Upwelling began to occur when the direction of wind changed from north to south between May and June.Upwelling became weaker during August and September,when the wind direction had changed from south to north.It has been found that in the study area the southwest monsoon,blowing strongly across the Zhejiang coastal area from late June to early August,caused the bottom waters to reach the surface during that time,exerting an important influence on the upwelling.
出处
《中国海洋大学学报（自然科学版）》
CAS
CSCD
北大核心
2007年第S1期235-240,共6页
Periodical of Ocean University of China
