2011年8月18日福州地区下击暴流分析  

Analysis of Downburst in Fuzhou on August 18, 2011

作　　者：陈齐川[1] 

机构地区：[1]福建省气象台,福州350001

出　　处：《福建气象》2012年第2期1-5,共5页

摘　　要：利用常规资料、自动站资料和多普勒雷达资料对福州地区2011年8月18日的两次下击暴流过程进行分析。结果表明：此次过程产生于副高控制下，水汽条件不好，但环境风切变强，不稳定能量大。在具有大量不稳定能量的背景下，高层的明显降温和强烈辐散，触发了此次强对流过程，造成两次下击暴流。第一次下击暴流由多单体风暴的不断合并加强造成的，第二次下击暴流由单单体风暴造成的。两次下击暴流都有反射率强中心逐步下降，速度场上在近地面产生辐散风场、中层径向辐合等特征。两次下击暴流产生的辐散气流与风暴分离后持续了相当长的时间。Two downburst events in Fuzhou on 18 August 2011 are analyzed with conventional observational datasets, automatic weather stations and Doppler radar data. The downhurst events occurred in the area controlled by the subtropical high, with poor moisture condition but strong vertical wind shear and large CAPE. In such unstable environment, the severe convective storms were triggered by obviously cooling and strong divergence in high level, resulting in the two downhursts. The first downburst was caused by process of multi-cells strengthening and merging. The other was caused by a single cell. The characteristics of radar echo morphology such as descending reflectivity core, low level divergence and middle level radial convergence were presented clearly in the process. The divergent airflow produced by the two downbursts lasted a long time after separation.

关 键 词：下击暴流 强对流风暴 多普勒雷达 

分 类 号：P426.64[天文地球—大气科学及气象学]