SPATIAL PATTERN OF THE AIR-SEA INTERACTION NEAR THE SOUTH CHINA SEA DURING WINTER

This paper delineates the coupled and principal patterns of sea surface temperature (SST) and surface wind near the South China Sea (SCS), and discusses the mechanism of air-sea coupling near the SCS and their association with the Asian monsoon. Singular value decomposition (SVD) and single field principal component analysis (PCA) are applied to the SST and wind anomalies from the 1979-1995 NCEP/NCAR reanalysis data. The leading SVD mode explains a predominant amount of squared covariance between the SST and zonal or meridional wind. During winter, the meridional wind's relation to the SST is better than the relation of zonal wind to SST. Despite the large magnitude of the squared covariance between SST and zonal or meridional wind, the spatial patterns of the first mode of SVD between the SST and meridional wind are similar. They both exhibit ellipse-shaped variance with the center near the SCS and a northeast-southwest oriented main axis. The spatial patterns of the leading mode of SVD between the SST and zonal wind are also similar to a certain degree. The zonal wind is not as closely correlated to the SST as the meridional wind is. These results suggest that the meridional wind and SST are strongly coupled during the winter season, and that there is a certain coupled action system in the SCS.