为研究逆风区回波结构的演变与中尺度强对流天气发生发展的关系,分析了2005年4月30日和6月22日在江西省境内有逆风区现象的强对流天气的多普勒雷达回波特征,对逆风区的回波强度与速度的演变进行对比分析后认为:逆风区不仅是暴雨判据,也是强对流天气的判据。逆风区的伸展高度一般较高,有逆风区的存在基本上都伴有剧烈的天气过程,只要逆风区的结构一直存在,强回波的反射率因子就不会减弱。本文提出了一种逆风区的三维结构模型,逆风区回波反映了强对流的生消结构,逆风区实为前方辐合上升、后方下沉的涡管结构,它是认识强对流天气系统三维结构的重要信息。
In order to study the relations between adverse wind area and the mesoscale strong convection, the severe weather echo characteristic within Jiangxi on April 30, 2005 and on June 22, 2005 is analyzed by comparing reflectivity with velocity in adverse wind area. The results indicate that the adverse wind area is not only the rainstorm criterion but also the strong convection criterion. The adverse wind areas are always accompanied by the severe weather with the high extending height. The strong reflectivity could not be weakened when the structure of adverse wind area exists. This paper proposes a model of the three dimensional structure about adverse wind area, which reflects the strong convection appearance and disappearance evolution with the revolving scroll structure of the frontal rising and rear sinking. The adverse wind area is the important information for studying three dimensional strueture of strong convection weather system.