Boreal Summer Intraseasonal Oscillation and Its Possible Impact on Precipitation over Southern China in 2019  

作　　者：Jieli HONG Zongjian KE Yuan YUAN Xie SHAO 

机构地区：[1]Laboratory for Climate Studies,National Climate Center,China Meteorological Administration,Beijing 100081

出　　处：《Journal of Meteorological Research》2021年第4期571-582,共12页气象学报（英文版）

基　　金：Supported by the National Key Research and Development Program of China(2018YFC1505603);National Natural Science Foundation of China(41975088 and 41575074);China Meteorological Administration Special Public Welfare Research Fund(GYHY201306024);State Oceanic Administration International Cooperation Program(GASI-IPOVAI-03)。

摘　　要：Based on daily precipitation observation data in China,the intraseasonal oscillation(ISO)features of summer precipitation over southern China in 2019 have been investigated by wavelet and band-pass filtering analyses.The results show that enhanced(suppressed)precipitation occurred over southern China during early(late)boreal summer2019.The signals of both 10-20-and 30-60-day ISO in southern China are remarkable,with the amplitude of the10-20-day ISO larger than the 30-60-day ISO in boreal summer 2019.The synergistic effect of the 10-20-and 30-60-day ISO wet phases was found to exert a tremendous influence on persistent heavy precipitation in July 2019,when the amount of precipitation reached its maximum in southern China since 1981.The atmospheric circulation and convection evolution characteristics of both 10-20-and 30-60-day ISO are further investigated.An anomalous low-level anticyclone over the South China Sea is prominently linked to the wet phase of the 10-20-day ISO,whereas an anomalous low-level cyclone over southern China is dominantly associated with the wet phase of the 30-60-day ISO.Both events enhance the water vapor convergence and ascending motion over southern China.Thus,the atmospheric circulation that accompanied the synergism of the wet phases of the 10-20-and 30-60-day ISO resulted in persistent heavy precipitation over southern China in July 2019.

关 键 词：heavy precipitation intraseasonal oscillation(ISO) southern China 

分 类 号：P426.6[天文地球—大气科学及气象学]