基于多源探测资料的一次广州局地强对流垂直结构分析

AN ANALYSIS OF THE VERTICAL STRUCTURE OF LOCAL STRONG CONVECTION IN GUANGZHOU BASED ON MULTI-SOURCE DETECTION DATA

关键词:  相控阵雷达  双偏振雷达  垂直结构  局地强对流  广州

Key words:  phased array radar  dual polarization radar  vertical structure  strong local convection  Guangzhou

摘要:

基于X波段相控阵雷达、S波段双偏振雷达、微波辐射计、风廓线雷达、毫米波云雷达等多源高时空分辨率新型遥感探测资料，对广州后汛期一次局地强对流过程的大气热力、动力及云物理结构变化特征进行了综合分析。结果表明：(1) 强对流前8小时前，局地LI、CAPE、SI等对流参数就达到并远远超过了短时强降水的阈值；临近降水大气层结仍向不稳定发展，水汽条件向有利的方向发展; (2) 午后局地风形成辐合，上升气流加强，近地层出现弱垂直风切变和低空急流脉动，对强对流的发生发展有一定的指示意义; (3) CINRAD/SA-D雷达CR、DBZM HT、TOPS、VIL等变化与强降水和地面大风的发展有很好的对应关系，同时低层风场观测到阵风锋特征；XPAR-D雷达更高时空分辨率的探测可清晰显示对流发展旺盛阶段的ZDR弧、KDP柱、ZDR柱、V型缺口等特征，为判断雷暴云团的发展程度和预警提供重要信息。

Abstract:

Based on multi-source high temporal and spatial resolution new remote sensing detection data such as X-band phased array radar, S-band dual-polarization radar, microwave radiometer, wind profiler radar, millimeter-wave cloud radar, etc. Atmospheric thermal, dynamic and cloud physical structure change characteristics are comprehensively analyzed.The results are shown as follows: (1) Eight hours before strong convection, local LI, CAPE, SI and other convective parameters reached or exceeded the short-term heavy precipitation threshold. Before the precipitation approached, the atmosphere tended to be unstable, and the water vapor condition developed in a favorable direction.(2) Local winds converged in the afternoon, updraft strengthened, a weak vertical wind shear and low-level jet pulsation appeared in the near-surface layer, which were somewhat indicative for the occurrence and development of strong convection.(3) The changes of CR, DBZM HT, TOPS, and VIL of the CINRAD/SA-D had a good corresponding relationship with the development of heavy precipitation and ground wind,while, the characteristics of gust fronts were observed in the low-level wind field. The detection of XPAR-D with higher spatial and temporal resolution clearly showed the characteristics of ZDR arc, KDP column, ZDR column, and V-shaped notch in the stage of vigorous convection development provide important information for judging how well thunderstorm cloud clusters developed and their early warning.