【摘要】 本文给出了 2 0 0 1年 8月 2 4～ 2 5日在 50 0hPa西北气流下产生的对流云团单体合并、加强形成中尺度对流复合体 (简称MCC)的发展过程 ,并对其发生的环境条件进行了分析。结果表明 ,当低层水汽充足、局地大气具有潜在不稳定能量和适当的触发条件时 ,在 50 0hPa西北气流控制的地区会出现中尺度对流复合体 ,产生强降水天气。本次过程主要是低层气流的辐合造成水汽、能量的聚积 ,低层的增暖增湿 ,高层的干冷空气入侵 ,形成了强的对流不稳定区 ;中尺度扰动及低空偏南气流在地面静止锋上被迫抬升 ,引起中尺度对流云团发展合并 ,是MCC生成的主要机制。更多还原

【Abstract】 This paper gives the developing process of mesoscale convective complex(MCC) produced by consolidation and strengthen of convection cell brought by northwest air stream on 500hPa level from 24 to 25 August, 2001 and out carries analysis of the environment condition of it. The result shows that,if water vapor on low levels is abundant and local atmosphere has latent instability energy and suitable trigger mechanism, then MCC and strong rainfall will appear in the region controlled by northwest air stream on 500hPa level. The collection of water vapor and energy produced by convergence of air stream on low levels in this process is major. The strong convective instability region is formed by enhancement of temperature and humidity on low levels and intrusion of cold air on higher levels. The lifting of mesoscale turbulence and air stream inclined to south on low levels forced by stationary front on surface brings on development and consolidation of mesoscale convective cloud cluster, it is major out-growth mechanism of MCC.更多还原