大气科学2011，Vol.35Issue(3)：560-570,11.
热带大气季节内振荡对华南前汛期降水的影响
Impact of the Madden-Julian Oscillation on Pre-flood Season Precipitation in South China
摘要
Abstract
Impact of the Madden-Julian Oscillation (MJO) on pre-flood season precipitation in South China is investigated based on a real-time MJO index and observed daily rainfall from gauge stations. It is shown that the rainfall patterns change from enhanced to suppressed in South China at intraseasonal timescales as the MJO moves from the Indian Ocean to the western Pacific. The most significant positive and negative anomalies are found in phase 4 and phase 7, respectively. The maximum positive and negative anomalies of regional mean rainfall are 17 ％ and 11％ relative to the climatological regional mean, respectively. Such different rainfall regimes are associated with the corresponding changes in large-scale background fields such as the western Pacific subtropical high (WPSH), moisture,and vertical motion. In phase 4, when the MJO is mainly over the Indian Ocean, the WPSH shifts farther westward, the moisture and upward motion in South China are increased, such environment is in favor of rainfall enhancement. In contrast, in phase 7, when the MJO enters the western Pacific, the WPSH retreats eastward, the moisture and upward motion in South China are decreased, such environment is in favor of rainfall suppression.关键词
热带大气季节内振荡/前汛期/降水/华南/实时热带大气季节内振荡指数Key words
Madden-Julian Oscillation (MJO)/ pre-flood season/ precipitation/ South China/ Real-time Multivariate MJO (RMM) index分类
天文与地球科学引用本文复制引用
章丽娜,林鹏飞,熊喆,吴洪..热带大气季节内振荡对华南前汛期降水的影响[J].大气科学,2011,35(3):560-570,11.基金项目
国家重点基础研究发展计划项目2010CB950903、2009CB421100,中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室自由探索,国家自然科学基金资助项目40906012,国家高技术研究发展计划项目2010AA012303 （）
