摘要
受"凤凰"低压和冷空气共同影响,2008年8月1～2日安徽省东部和江苏西部部分地区出现大雨,局部地区暴雨到特大暴雨。滁州和全椒24 h雨量分别为429 mm和414 mm,此次特大暴雨具有局地性和降水强度大的特点。使用南京和马鞍山双多普勒雷达时间同步观测资料,对此次暴雨的三维风场进行反演,在此基础上,研究了暴雨的三维风场结构。由雷达回波分析可知,此次暴雨是由β中尺度对流系统造成的,在β中尺度对流系统内部还有γ中尺度对流单体,对流单体发展非常旺盛。中低层切变线自西向东移入降水区后,在该地区停留较长时间,加之有充足的水汽供应,造成了局地特大暴雨。在垂直剖面内,对流系统发展旺盛,强降水区上空回波较强且对应着较强的上升气流区,而在强回波中心区的两侧均有下沉气流。当切变线减弱并移出降水区后,强降水停止。
Due to the effect of the low-pressure system of Fung-Wong and the cold air, it produced a heavy precipitation in the east region of Anhui Province in China, up to 429 mm rainfall in Chuzhou and 414 mm in Quanjiao from 08：00 on 1 to 08：00 on 2 August 2008. It is a local and short time heavy rain. The three dimensional wind fields were retrieved by the volume scan data of the dual-Doppler radar located in Nanjing and Maanshan cities. The evolution of the 3D wind fields of the heavy rainstorm were investigated. It is a convective cloud precipitation based on the radar echo analyses. The meso-β-scale convective system （MβCS） and the meso-γ- scale system located on the MβCS played an important role on this heavy rainstorm. The meso-β-scale convective cloud has high precipitation efficiency. The dual-Doppler retrieved wind reveals that the heavy rainstorm was caused by the meso-β-scale shear line and the meso-β-scale convergence lines at the low and the medium levels. The shear line spread from west to east. It stayed on the Chuzhou and Quanjiao areas for period of time. The shear line triggered and maintained the heavy rainstorm. On the other hand, the plentiful water vapour was transported to the rainstorm area continuously. These factors greadtly availed to the heavy rainstorm. There were strong convergence and vorticity at the low and medium levels of the MβCS. When the shear line at the low and medium levels moved out of the rainstorm area, the precipitation began to weak remarkably too.
出处
《高原气象》
CSCD
北大核心
2009年第6期1422-1433,共12页
Plateau Meteorology
基金
科技部国家重点基础研究发展规划项目(2004CB418305)
国家自然科学基金项目(40605014)
科技部国家高技术研究发展计划(863计划:2007AA061901)
中国气象科学研究院灾害天气国家重点实验室基本科研项目共同资助
关键词
暴雨
三维结构
双多普勒天气雷达
风场反演
Rainstorm
Three dimensional structure
Dual-Doppler weather radar
Wind retrieval
