|
|||||
|
|
Numerical simulation of the sudden rainstorm associated with the remnants of Typhoon Meranti (2010) |
|
| Authors: | ZHOU Lingli DU Huiliang ZHAI Guoqing WANG Donghai |
| Institution: | 1. State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing 100081; Zhejiang Province Meteorological Observatory, Hangzhou 310017 2. Zhejiang Province Meteorological Observatory,Hangzhou,310017 3. Department of Earth Sciences, Zhejian9 University, Hangzhou 310027 4. State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing 100081 |
| Abstract: | The Advanced Research Weather Forecasting (ARW) model was used to simulate the sudden heavy rainstorm associated with the remnants of Typhoon Meranti in September 2010. The results showed that the heavy rainfall was produced when the remnant clouds redeveloped suddenly, and the redevelopment was caused by rapid growth of micro/mesoscale convective systems (MCSs). As cold air intruded into the warm remnant clouds, the atmosphere became convectively unstable and frontogenesis happened due to strong wind shear between weak northerly flow and strong southwesterly flow in the lower levels. Under frontogenesis-forcing and warm-air advection stimulation in updrafts, vertical convection developed intensely inside the remnant clouds, with MCSs forming and maturing along the front. The genesis and development of MCSs was due to the great progress vertical vorticity made. The moist isentropic surface became slantwise as atmospheric baroclinity intensified when cold air intruded, which reduced the convective instability of the air. Meanwhile, vertical wind shear increased because the north cold air caused the wind direction to turn from south to north with height. In accordance with slantwise vorticity development (SVD), vertical vorticity would develop vigorously and contribute greatly to MCSs. Buoyancy, the pressure gradient, and the lifting of cold air were collectively the source of kinetic energy for rainfall. The low-level southwesterly jet from the western margin of the Western Pacific Subtropical High transported water and heat to remnant clouds. Energy bursts and continuous water vapor transportation played a major role in producing intense rainfall in a very short period of time. |
| Keywords: | remnant clouds heavy rainfall frontogenesis vertical convection slantwise vorticity development kinetic energy budget |
| 本文献已被 CNKI 万方数据 SpringerLink 等数据库收录！ | |
| 点击此处可从《大气科学进展》浏览原始摘要信息 | |
| 点击此处可从《大气科学进展》下载免费的PDF全文 | |