Increasing Precipitation in Early Winter Over the Southern China During the Past 40 years

Southern China (SC) has experienced increasing precipitation in early winter over the past 40 years, which has been attributed to increasing precipitation over the tropical Indian Ocean (TIO) in this study. In early winter, the positive diabatic heating released by the increasing precipitation over the TIO triggers a strong Matsuno-Gill response. The Kelvin wave of the Matsuno-Gill response forms an anomalous anticyclone over the Western North Pacific (WNPAC) in the lower troposphere, which strengthens water vapor transport from the ocean to SC and induces an increase in precipitation. In late winter, the increasing TIO precipitation is relatively weak, and the trend of SC precipitation is likely caused by factors outside the Indian Ocean.