Variation of the gale process over the South China Sea from 1979 to 2021 and its response to East Pacific Sea surface temperature

Abstract

By using ERA5 reanalysis data, this paper combined existing research definitions of gale processes to analyze the variation characteristics of gale processes occurring in the South China Sea region, and to study the response of the gale process to East Pacific sea surface temperature. The results indicate that the gale process shows the significant annual variation and the most frequent in winter and least frequent in summer. While there is no significant trend in the frequency of gale processes in each season. There is a significant negative correlation between the frequency of gale process and the East Pacific sea surface temperature in spring, autumn, and winter. When the sea surface temperature in the eastern Pacific rises abnormally, the frequency of gale processes in the South China Sea decreases. When abnormally high, the frequency of gale process in the South China Sea increases. In summer, this relationship is the opposite. When sea surface temperature is abnormal, the anomalous anticyclone triggered in the western Pacific, and has a weakening effect on the prevailing winds in the South China Sea, leading to a reduction in high wind speed and gale events, thereby reducing the frequency of gale process.