通过对南海季风实验（SCSMEX）期间布设于南海中部的3个ATLAS海洋锚定浮标所观测的资料进行Morlet小波分析,发现南海次表层水温存在显著的季节内变化,尤其是在冬半年.水温季节内变化主要集中在50～100 m深度,振幅变化可以达到1～2℃.造成次表层水温如此大振幅变化的原因,是在海面风应力强迫下温跃层产生的垂直位移所致.这一发现揭示出南海上层海洋垂向季节内变化的重要特征. Morlet wavelet analysis of the observed data from three ATLAS marine anchored buoys located in the central South China Sea during the SCSMEX showed that there was a significant intraseasonal variation in subsurface water temperature in the South China Sea, especially in the winter half. The internal changes are mainly concentrated in the depth of 50 ~ 100 m, and the amplitude changes can reach 1 ~ 2 ° C. The reason for the large amplitude variation of the subsurface water temperature is the vertical displacement caused by the thermocline under the forced wind stress on the sea surface. Discover reveals important features of the vertical seasons within the upper South China Sea.