Atmospheric Circulation Characteristics of Heavy Precipitation Events and Impact of Sea Surface Temperature over the Southern China in the Autumn of 2016

This paper studies the atmospheric circulation characteristics of the abnormally heavy precipitation events over southern China in the fall of 2016 and the impact of Sea Surface Temperature (SST) based on the precipitation data from the weather stations in China, UK Hadley Center SST, and NCEP/NCAR reanalysis datasets. Results show that the subtropical westerly jet in East Asia was much stronger in the fall of 2016 and southern China was located to the right of the jet stream entrance, which was conducive to an ascending motion. The western Pacific subtropical high was also much stronger than normal, with a larger area and more northwestward location. The anomalous southeasterly winds on the southwest side of the western Pacific subtropical high transported warm and moist air from the tropical Pacific to southern China, leading to heavy precipitation there. Landing typhoons along the coast of southeast China also contributed to heavy precipitation. Further analysis shows that the heavy rainfall event was mainly related to the abnormally higher SST over the equatorial western and southeastern Pacific simultaneously on interannual time scales. These SST anomalies could affect East Asian atmospheric circulation through exciting downstream-propagating teleconnection wave trains or Gill-type atmospheric responses. The above results are further confirmed by a series of numerical model simulations, using Community Atmosphere Model Version 5.3 (CAM 5.3).