热带气象学报2012，Vol.28Issue(4)：506-516,11.DOI:10.3969/j.issn.1004-4965.2012.04.009
广东高空槽后暴雨的多尺度天气特征及概念模型
THE STUDY OF MULTI-SCALE SYSTEM AND CONCEPTUAL MODEL OF THE TORRENTIAL RAIN UNDER THE FORWARD-TILTING TROUGH
摘要
Abstract
Guangdong suffered a rarely observed torrential rain on 7 May, 2010, which occurred behind an upper-level trough. Based on meteorological observation data and NCEP analysis data, the characteristics of large- and synoptic-scale circulation and the mechanisms of the unusual torrential rain are analyzed with a linear, diagnostic model for local meridional circulation and a scale separation method. The results show that the westward movement of South Aisa High with the northward movement of an upper-level westerly jet was in favor of the upper-level divergence over Guangdong. Guangdong was controlled by the northwest airflow in the rear of the upper-level trough at 500 hPa and a shear line and a surface cold front were to the north of Nanling Mountains. Under this forward-tilting trough circumstance, it would probably reinforce the release of unstable energy. Numerical quantitative diagnosis shows that the contributors to the local meridional circulation associated with the torrential rain are mainly latent heating and horizontal temperature advection. Latent heating is the major contributor and provides positive feedback to the torrential rain, while horizontal temperature advection plays an important role in triggering the torrential rain. Further analysis with the scale separation method shows that the impact of weak cold air that crosses Nanling Mountains is important to the location and enhancement of the torrential rain. Therefore, more attention needs to be paid to activities of the weak cold air and the topographic effects in forecasting the torrential rains during the annually first rainy season of South China.关键词
天气学/暴雨/高空槽/数值诊断/冷空气/概念模型Key words
torrential rains/high-level trough/numerical diagnosis/cold front/conceptual weather model分类
天文与地球科学引用本文复制引用
吴乃庚,林良勋,曾沁,伍志方,杨国杰,罗聪..广东高空槽后暴雨的多尺度天气特征及概念模型[J].热带气象学报,2012,28(4):506-516,11.基金项目
国家自然科学基金重点研究项目40730951和公益性行业科研专项GYHY201106003共同资助 （）
