一次强飑线云结构特征的卫星反演分析

Analysis on Satellite Retrieval of Cloud Structure in a Severe Squall Line Process

利用NOAA卫星AVHRR资料,对2006年4月28日山东一次春季强飑线过程进行了分析,重点研究了卫星资料多光谱综合分析的强对流云微物理特征和卫星识别的对流强信号,并与雷达、FY-2C卫星观测资料进行了对比分析。结果表明:(1)RGB合成图能清晰地显示云顶的结构、纹理、云砧、组成、高度及云厚等信息,是一种很方便的分析工具。(2)多光谱综合分析归纳出卫星探测对流强信号:云顶的对流结构和纹理突出,有明显的云砧,云顶以小粒子为主,粒子有效半径Re随高度增长缓慢,云团上部存在明显的Re随高度递减带,云顶Re和-dRe/dT能定量指示对流的强弱。据此,卫星识别出强中心A比实际降雹提前了近1h,比飑线发生提前了2.5h,比多普勒雷达监测提前了近2h,特别是识别出的强中心B比实际降雹提前了近4h。卫星探测为强对流天气的监测预报和预警提供了一种新途径。

Using the NOAA AVHRR data,combining with radar and FY-2C geostationary satellite data,a severe squall line process occurred in Shandong Province on April 28,2006 was analyzed.The results show：（1） The convective characteristics of cloud can be seen from the RGB composite image.（2） Based on the comprehensive multispectral analysis,some evidently qualitative signs for severe storm have been summarized that include the convective structure,clear bulbs and anvil,the cloud top mainly composed of small particles,the effective radius（Re） grow slowly and then decreased with the height.The cloud top Re and its growth rate can be as quantitative indices.This severe storm can be identified 1 h and 2.5 h earlier than the occurrence of hailstorm and squall line,2 h earlier than the Doppler radar based on these proposed signs and indices,which provide a new way for application of satellite monitoring and warning of severe storm.