The Impacts of East China Sea Kuroshio Front on Winter Heavy Precipitation Events in Southern China

Abstract

AbstractThe wintertime Kuroshio sea surface temperature (SST) front has the significant climate effects on Southern China. The study demonstrates a close relationship between heavy precipitation over Southern China and Kuroshio SST front in winter. More than half winter heavy rainfall events in Southern China are proved to be resulted from strong High‐frequency Variability events of the sea surface Wind Coupled with Precipitation (HV‐WCP events) over Kuroshio SST front. One day before strong HV‐WCP events, the initial precipitation appears over Middle‐lower Yangtze River due to the significantly enhanced frontal intensity. Then, precipitation generates low‐level cyclone and southeasterly wind anomalies, after it moving into Kuroshio front area because of the winter monsoon. The significant marine atmospheric boundary layer (MABL) height gradient over Kuroshio leads to plentiful moisture transporting from MABL into the free atmosphere and enhances the local precipitation again. This process further causes the large‐scale stratus rainband extending to Southern China and enhancing the heavy rainfall locally. Especially in 2008 winter, several processes of a strong HV‐WCP event followed by continuous weak ones are conducive to the low‐temperature‐precipitation disaster in Southern China.