摘要
利用卫星和多普勒雷达的高时空分辨率观测资料 ,对 1 998年 6月 8～ 9日香港暴雨过程中的中尺度对流系统进行分析 ,表明 :( 1 )此次暴雨是冷锋前暖区的对流性降水 ,期间有 3次强降水过程 ,每次维持时间 2～ 5小时 ,中尺度对流系统是造成强降水的主要系统。 ( 2 )雷达回波强度与卫星云图对比发现 ,强回波区全位于云顶温度≤ - 32℃的云团内 ,但具体分布有两种情况 :一种强回波区位于通常所说的发展强盛的α中尺度云团的边缘TBB等值线密集区 ,一种如尺度较小的线状强回波则位于两个β中尺度云团 (云顶温度≤ - 5 2℃ )之间。这利用常规观测资料是无法识别的。 ( 3)分析单多普勒雷达反演的水平风场发现 :大尺度的环境风场中 ,存在 β中尺度系统的独立流场 ;中尺度云团内部的流场辐合与强回波带相对应。
An analysis for the meso-scale convective systems in a heavy rain process during June 8 to 10 1998 is performed using the data observed by meteorological satellites and the Doppler radar. The following results are drawn. 1) This heavy rain process is caused by meso-scale convective systems, and there are three different periods in which strong precipitation processes happen. 2) Comparing the reflectivity observed by radar and the cloud distribution observed by satellite, it is found that although the area of strong reflectivity is located in the areas where the temperature of the cloud top is less than -32℃, there is still two kinds of distributions. One is that the heavy rainfall is located in the area where the gradient of the TBB isoline is biggest, and the other is that the heavy rainfall is located in the area between two meso-β-scale cloud groups, where the temperature of the cloud top is less than -52℃. This situation cannot be distinguished by the routine observation. 3) Based on the horizontal wind field retrieved from Doppler velocity, it is found that there is isolated construction of meso-β-scale wind field. The convergence between the southwest wind and the south wind and the convergence between the southwest wind and the west wind cause the strong precipitation.
出处
《大气科学》
CSCD
北大核心
2004年第5期713-721,i001-i004,共13页
Chinese Journal of Atmospheric Sciences
基金
国家自然科学基金资助项目 40 2 3 3 0 3 6
高等院校重点实验室访问学者基金资助项目共同资助
