南海海面风、浪场时空变化特征及其关系分析

Analysis of the temporal and spatial variations in the wind and wave over the South China Sea

利用长时间序列的卫星观测数据,对南海海域的风、浪场时空分布及其相互关系进行了分析。结果显示,海面风距平场VEOF分解后得到的第一模态具有明显的季节变化,即季风特征,说明季风是影响整个南海风速的主要因素;第二模态具有较强的区域变化特征,是季风转换时期的距平场特征;第三模态反映的是海面风距平场受陆地地形影响所表现的分布特征。有效波高距平场EOF分解后得到的第一模态、第二模态与风距平场的前2个模态的空间分布较为相似,并且,风、浪距平场第一模态间的相关系数达0.76,均说明南海作为边缘海其波浪场与风场变化有很好的相关性。有效波高第三模态的分布与风场的第三模态相关性较弱,反映的是受海底地形影响所表现的分布特征。

Based on satellite remote sensing products, the seasonal and interannual variations in the wind and wave over the South China Sea （SCS） were presented in the study. A vector empirical orthogonal function （VEOF） method was employed to study the temporal and spatial patterns of the wind field. Results indicate that the first VEOF is a seasonal oscillation mode, which represents the monsoon feature in the SCS. The second VEOF is an approximate annual oscillation mode, it represents the wind field features during the monsoon transition period. The third VEOF shows that the wind field is the land-sea interaction mode. For SWH, an empirical orthogonal function （EOF） method was employed and the similar two modes are forced by the first two modes of wind data, the third mode is caused by the bottom topography variation. The correlation coefficient （CC） between wind field＇s first mode and SWH＇s first mode is 0.76, which shows that the wave variation is forced by the sea surface wind. The two third modes are nearly unconnected, there may be a link between the bottom topography and SWH＇s third mode.