| 2003年7月8～9日江淮流域暴雨过程中涡旋的结构特征分析 |
| |
| 引用本文： | 周玉淑,李柏.2003年7月8～9日江淮流域暴雨过程中涡旋的结构特征分析[J].大气科学,2010,34(3):629-639. |
| |
| 作者姓名： | 周玉淑 李柏 |
| |
| 作者单位： | 1.中国科学院大气物理研究所, 北京, 100029 |
| |
| 基金项目： | 国家重点基础研究发展规划项目2009CB421505， 科技部公益性行业 (气象) 科研专项项目GYHY200906004， 国家自然科学基金资助项目40975034， 国家科技支撑计划项目2008BAC37B01。 |
| |
| 摘 要： | 2003年淮河流域梅雨期 (6月29日～7月11日) 的强降水过程有三次: 6月29日～7月1日、 7月3～5日及7月8～11日。本文对7月8日12时～9日12时期间湖南、 安徽和江苏发生的强降水过程的中尺度数值模式MM5的输出资料进行了诊断分析。分析结果表明: 除大尺度系统的配置有利于此次降水的发生以外, 此次降水主要发生在由西南及偏南暖湿气流与偏北气流辐合形成的梅雨锋切变线上, 切变线上辐合中心处生成并发展的两个中尺度低涡是造成降水的直接系统。低空西南风急流形成了从孟加拉湾、 南海至华东地区的强水汽输送带以及湖南、 安徽和江苏的水汽辐合中心, 为暴雨创造了十分有利的水汽条件。在低层切变线的辐合中心处有两个低涡分别生成或发展, 并沿切变线向东北方向移动, 这两个低涡生成的位置是低空急流左前侧急流达到极值的区域 (也是正涡度中心区), 其生成可能与低空急流的加强有关。在低涡附近, 低层水汽辐合较强, 且对流层中低层形成了强正涡度中心和强散度中心相耦合的动力结构, 并有强上升运动维持, 使得低层辐合的水汽被抬升到对流层高层, 有利于暴雨的发生。
|
| 关 键 词： | 切变线 低涡 结构分析 |
Structural Analyses of Vortex Causing Torrential Rain over the Changjiang-Huaihe River Basin during 8 and 9 July 2003 |
| |
| ZHOU Yushu and LI Bai.Structural Analyses of Vortex Causing Torrential Rain over the Changjiang-Huaihe River Basin during 8 and 9 July 2003[J].Chinese Journal of Atmospheric Sciences,2010,34(3):629-639. |
| |
| Authors: | ZHOU Yushu and LI Bai |
| |
| Institution: | 1.Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 1000292.Meteorological Observation Center of China Meteorological Administration, Beijing, 100081 |
| |
| Abstract: | There were three torrential rain processes during the Meiyu period of 2003 over the Changjiang-Huaihe River basin, namely, from 29 June to 1 July, from 3 to 5 July, and from 8 to 11 July, respectively. Utilizing the numerical simulation data outputted by MM5 on the torrential rain process occurring over the Hunan, Anhui and Jiangsu provinces during 8-9 July 2003, the structure of vortex, which caused the torrential rain directly, was analyzed. Analyses from the simulation results indicated that the configuration of large-scale systems was favorable for the development of the precipitation, the direct raining system was two mesoscale vortexes at the convergence centers along a shear line of the Meiyu front. The shear line consisted of the convergence of warm and moist southerly flow and the relative dry northerly flow. The southwesterly jet at lower levels contributed the strong water-vapor transport belt from the Bay of Bengal and the South China Sea to East China and the water-vapor convergence centers in Hunan, Anhui and Jiangsu provinces, which provided the sufficient water-vapor content. At the convergence centers along the shear line at lower levels, two vortexes formed or developed, and then moved northeastward along the shear line. Furthermore, the two vortexes were located at the left-forward position of the maximum zone of the jet (it is also the positive vorticity center). Near the vortexes, there was strong convergence of water vapor at lower levels, and the coupling dynamical structure of positive vorticity region and the divergence center formed, which caused strong upward motion in the lower and middle troposphere, and had the convergent water vapor at the lower level lifted to the high level, it was beneficial for the occurrence and development of heavy rainfall. |
| |
| Keywords: | shear line vortex structural analysis |
| 本文献已被 CNKI 万方数据 等数据库收录！ |
| 点击此处可从《大气科学》浏览原始摘要信息 |
| 点击此处可从《大气科学》下载免费的PDF全文 |
|
