吕宋海峡Ekman输运和南海SST的相关性分析

Correlation analysis between Ekman transport through the Luzon Strait and SST in the South China Sea

在利用1950—2009年NCEP(National Center for Environmental Prediction)资料分析风场数据的基础上,计算吕宋海峡的Ekman输运,研究表明其存在显著的季节变化,除了夏季外,其它季节均为由太平洋向南海输运。分析吕宋海峡Ekman输运和南海海盆表征上层热力状况的海表面温度SST(Sea Surface Temperature)之间的关系发现:在年内时间尺度上,两者不存在显著的同期相关,Ekman输运对SST的影响开始于一个月之后,从北部向南扩展,第二个月最为明显,并扩展至整个海盆,第三个月开始衰减,第四个月影响消失,且相关性为正;在年际尺度上,吕宋海峡Ek-man输运的异常同南海SSTA(Sea Surface Temperature Abnormal)的第二模态存在显著的相关联系,并且吕宋海峡Ekman输运和南海SSTA的相关关系在北部为正,南部为负。吕宋海峡Ekman输运调制南海大尺度环流,通过暖、冷平流的作用影响南海SST的变化。

Based on the wind data archived in the National Center for Environmental Prediction（NCEP） from 1950 —2009,Ekman transport through the Luzon Strait（ETLS） is calculated.It is shown that ETLS is from the western Pacific Ocean to the South China Sea（SCS） all the year except in summer,and varies significantly with seasons.Correlation analysis indicates a positive relationship between ETLS and sea surface temperature（SST） in the SCS on the seasonal scale.The influence of ETLS on the SST starts after the first month and extends from the northern to the southern part of the basin in the SCS,reaches the maximum significance in the second month throughout the whole basin,decays in the third month and disappears in the fourth month.On the interannual scale,the ETLS anomaly is significantly related with the second mode of SST anomaly（SSTA） with a correlation index positive and negative in the northern and southern SCS,respectively.The basin-scale circulation in the SCS is modulated by the ETLS because the SST varies with the advection of cold or warm waters.