摘要
使用η模式对１９９５年８月２４日四川盆地西部一次突发性暴雨进行了数值模拟和无高原切变线、无西昌小高压的数值试验。由试验结果分析得出：（１）高原切变线活动可使四川盆地西部暴雨增强，而西昌小高压的存在则使四川盆地西部暴雨减弱；（２）高原切变线活动使暴雨增强的主要机制是暴雨区上空对流层低层流场辐合、上升运动、正涡度、水汽通量辐合和对流层中层流场辐合、水汽通量辐合等的加强；（３）对流层低层的动力、水汽条件对暴雨发展尤为重要。
By using the ETA model,a numerical simulations was done for a sharp heavy rain in the west Sichuan basin on 24 August,1995 and the numerical experiments without shear line over Qinghai -Xizang Plateau and Xichang small high were also done for the heavy rain. The results of numerical experiments are as follws: (1) The activity of the shear line over the Plateau can strengthen the heavy rain in west Sichuan Basin, but it will be weaken when there is the Xichang small high. (2) The main mechanism of strengthening heavy rain caused by the activity of the shear line over the Plateau is that strengthening of the convergence of vapour flux and flow field,positive vorticity,ascending motion in lower troposphere and convergence of vapour flux and flow field in middle troposphere over the heavy rain area. (3) The vapour and dynamic conditions in lower troposphere are very important for the development of heavy rain.
出处
《高原气象》
CSCD
北大核心
1997年第3期306-311,共6页
Plateau Meteorology
基金
四川省气象局1995年重点课题
关键词
切变线
暴雨
数值试验
盆地
Shear line Sharp heavy rain Numerical experiment
