| 摘要: |
| 对红外卫星云图和高低空天气形势的分析表明,2001年8月5日发生在上海的特大暴雨是副热带高压南侧的热带云团发展而成,与之相伴的环流系统是形成于东风带中的热带低压。对其进一步的诊断分析发现:(1)热带低压具有深厚的热带天气系统结构特征,自形成后,对流层中低层为正涡度区,其上为负涡度区,散度场高空存在强辐散层;(2)暴雨发生前,流场上存在有利于对流发展的垂直环流结构;(3)副高减弱断裂导致热带低压转向经过上海,海上高压的阻挡作用有利于低压在上海维持较长的时间并发展;(4)在暴雨发生前一天就有明显的水汽通量中心,并伴有较好的能量和稳定度条件。 |
| 关键词: 暴雨 热带低压 诊断分析 |
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| 基金项目:基础研究重大项目前期研究专项2001CCA02200;973项目(G1998040907);高等学校重点实验室访问学者基金共同资助 |
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| ANALYSIS OF TROPICAL DEPRESSION RAINSTORM IN SHANGHAI |
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YANG Yin-ming, ZHENG Yong-guang, TAO Zu-yu
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Laboratory for Severe Storm Research, Department of Atmospheric Science, School of Physics, Peking University, Beijing 100871, China
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| Abstract: |
| According to an analysis of infrared satellite imagery and synoptic charts,it is found that the Tropical Cloud Cluster (TCC) which comes from the south of Subtropical High Pressure (STP) directly caused the rainstorm which happened on August 5,sup>th of 2000 in Shanghai,and the circulation system relating to the TCC formed in the easterly. After further studies using diagnostic analysis method,we found that: (1) The Tropical Depression had a deep structure of tropical weather system,including a positive vorticity area in the low-to mid-troposphere,negative vorticity area and a strong divergence layer was in the upper-troposphere. (2) there is a typical cyclones vertical circulation structure in the vertical wind field just before the occurrence of the rainstorm. (3) The Tropical Depression moving toward northwest then turn to Shanghai when subtropical high pressure(STP) weakens and splits into two parts,and begins to develop over Shanghai because of the blocking of a High on the East Sea. (4) there is a clear center of vapor flux before the occurrence of the rainstorm,and energy and stability conditions are also in favor of the occurrence of the rainstorm. |
| Key words: rainstorm tropical depression diagnosis analysis |
