热带气象学：南海高压的年代际变化特征及其与我国华南降水的联系.pptxVIP

南海高压的年代际变化特征及其与我国华南降水的联系 引言 资料与方法 南海高压指数的定义 南海高压的年代际变化特征 南海高压与华南降水的关系 总结与讨论目录引言南海高压研究进展引言南海高压研究进展 The South China Sea high (SCSH) generally refers to a closed high pressure system, which appears over the Indo-China Peninsula or the South China Sea (SCS) at the mid-troposphere. The SCSH, a component of subtropical high systems, frequently appears from September to the following April. Comparison with the subtropical high over the Pacific Ocean shows that the SCSH fluctuates sharply and has a relatively short life cycle. According to the previous studies, the SCSH is closely related with rainfall variability over South China, due to a warm and moist flow located to the northwest of this anticyclone (Liang, 1995).引言南海高压研究进展 Some efforts have been devoted during the past decades into investigating the variation of the SCSH during the boreal summer (e.g. Wang, 1985; Chen, 1998; Lin, 2000; Wan, 2008). Some researches also pointed out that the SCSH is closely associated with summer rainfall. Although some efforts have been made to understand the SCSH variation over the tropics in boreal summer, relatively few studies have focused on its variation in wintertime, as well as the relationship with the rainfall over South China.——For instance, Wang (1985) defined an intensity index of the SCSH by the point grids where the 500-hPa geopotential height is greater than 5880gpm over the SCS (100°E–120°E, 10°N) 引言南海高压研究进展 Our focus here is on: the definition an appropriate occurrence index, so as to better describe the change of SCSH during wintertime at the mid-tropospheric. the relationship between the SCSH and wintertime rainfall over South China possible processes responsible for the formation of South China rainfall based on a vertically integrated moisture static energy (MSE) equation资料与方法资料出处及方法简介资料与方法资料出处及方法简介 daily variables derived from the National Centers for Environmental Prediction–National Center for Atmospheric Research (NCEP–NCAR) reanalysis data from 1948 to 2010 (