RELATIONSHIP BETWEEN SUMMER LOW-FREQUENCY RAINFALL OVER SOUTHERN CHINA AND PROPAGATION OF TROPICAL INTRASEASONAL OSCILLATION  

作　　者：SHEN Yu-yang REN Hong-li LI Wei-jing ZHANG Yu-jie ZUO Jin-qing 沈雨旸;任宏利;李维京;张玉洁;左金清(Public Meteorological Service Centre, China Meteorological Administration, Beijing 100081 China;Laboratory for Climate Studies ＆ CMA-NJU Joint Laboratory for Climate Prediction Studies, National Climate Center, China Meteorological Administration, Beijing 100081 China;Department of Atmospheric Science, School of Environmental Studies, China University of Geoscience, Wuhan 430074 China;Beijing Meteorological Bureau, Beijing 100089 China)

机构地区：[1]Public Meteorological Service Centre,China Meteorological Administration,Beijing 100081 China [2]Laboratory for Climate Studies&CMA-NJU Joint Laboratory for Climate Prediction Studies,National Climate Center,China Meteorological Administration,Beijing 100081 China [3]Department of Atmospheric Science,School of Environmental Studies,China University of Geoscience,Wuhan 430074 China [4]Beijing Meteorological Bureau,Beijing 100089 China

出　　处：《Journal of Tropical Meteorology》2018年第1期92-101,共10页热带气象学报（英文版）

基　　金：973 Program of China(2015CB453203,2013CB430203);China Meteorological Special Project(GYHY201406022);China National Science Foundation(41505065,41375062)

摘　　要：This study investigates the relationship between summer low-frequency rainfall over southern China and tropical intraseasonal oscillation(ISO) in the atmosphere by examining systematically the propagation features of the tropical ISO in terms of focusing on five large-scale low-frequency rainfall regimes in summer over southern China. It is demonstrated that there is a close linkage between the five rainfall regimes over southern China and the northward propagation of the tropical ISO. The moist ISO signals, which influence the low-frequency rainfall events in different regions of southern China, mainly propagate northwestward from the tropical ocean to the southeast of China. The southeast China rainfall regime is intimately associated with the moist ISO signals propagating northwestward from the equatorial mid-western Pacific Ocean. For both the Yangtze River regime and South of Yangtze River regime, the moist ISO signals over the northern South China Sea show an evident northward propagation towards the Yangtze River region, and then propagate westward. It is further found that the interaction between the northward propagation of low-latitude ISO signals and the southward propagation of high-latitude ISO signals can also make a clear influence on the low-frequency rainfall in southern China. For the Southern China regime, the moist ISO signals show a significant northward propagation from the Philippines. Moreover, for the rainless regime, southern China is under dry ISO signals' control, and the latter shows no clear propagation to southern China. This study may provide insights for the extended-range forecasting of summer rainfall in southern China.This study investigates the relationship between summer low-frequency rainfall over southern China and tropical intraseasonal oscillation（ISO） in the atmosphere by examining systematically the propagation features of the tropical ISO in terms of focusing on five large-scale low-frequency rainfall regimes in summer over southern China. It is demonstrated that there is a close linkage between the five rainfall regimes over southern China and the northward propagation of the tropical ISO. The moist ISO signals, which influence the low-frequency rainfall events in different regions of southern China, mainly propagate northwestward from the tropical ocean to the southeast of China. The southeast China rainfall regime is intimately associated with the moist ISO signals propagating northwestward from the equatorial mid-western Pacific Ocean. For both the Yangtze River regime and South of Yangtze River regime, the moist ISO signals over the northern South China Sea show an evident northward propagation towards the Yangtze River region, and then propagate westward. It is further found that the interaction between the northward propagation of low-latitude ISO signals and the southward propagation of high-latitude ISO signals can also make a clear influence on the low-frequency rainfall in southern China. For the Southern China regime, the moist ISO signals show a significant northward propagation from the Philippines. Moreover, for the rainless regime, southern China is under dry ISO signals＇ control, and the latter shows no clear propagation to southern China. This study may provide insights for the extended-range forecasting of summer rainfall in southern China.

关 键 词：summer low-frequency rainfall intraseasonal oscillation propagation composite analysis 

分 类 号：P466[天文地球—大气科学及气象学]