大气科学进展（英文版）
大氣科學進展（英文版）
대기과학진전（영문판）
ADVANCES IN ATMOSPHERIC SCIENCES
2010年
2期
315-327
,共13页
吴丽姬%黄荣辉%贺海晏%邵亚平%温之平
吳麗姬%黃榮輝%賀海晏%邵亞平%溫之平
오려희%황영휘%하해안%소아평%온지평
持续性暴雨%中国南方%季风活动%天气特征%南海夏季风爆发%倾斜涡度发展%爆发事件%季节
持續性暴雨%中國南方%季風活動%天氣特徵%南海夏季風爆髮%傾斜渦度髮展%爆髮事件%季節
지속성폭우%중국남방%계풍활동%천기특정%남해하계풍폭발%경사와도발전%폭발사건%계절
heavy rainfall%South China%pre-monsoon%moist potential vorticity
Persistent heavy rainfall events in South China can be divided into pre-and post-monsoon-onset events according to the onset of the South China Sea Summer Monsoon. In this study, daily rainfall data from 174 stations in South China and daily NCEP/NCAR reanalysis data are used to investigate pre-monsoon-onset events. The synoptic characteristics of pre-monsoon-onset heavy rainfall events are examined in detail. It is found that 21 heavy rainfall cases happened in the pre-monsoon period between 1961 and 2005. Among them, more than 60% of the events happened under a saddle pattern circulation. Using a case study, the role of the saddle field is investigated and slantwise vorticity development （SVD） theory is applied to diagnose the mechanisms for heavy rainfall development. It is found that a low-level saddle field and low-level jets result in the accumulation of warm moist air in the lower troposphere over South China and provide the necessary unstable conditions for heavy rainfall development. The existence of a saddle field plays an important role in maintaining these unstable conditions. The slantwise movement of the isentropic surface over South China can increase local vorticity and lead to strong vertical motion, which then triggers heavy rainfall.
