卫星遥感人工增雨作业条件 Ⅱ:层状云  

Seeding Conditions of Precipitation Enhancement Revealed by Multiple Spectral Data of Satellite.Ⅱ:Super-cooled Layer Clouds

作　　者：刘贵华[1] 余兴[1] 岳治国[2] 戴进[1] 徐小红[1] 朱延年[1] 

机构地区：[1]陕西省气象科学研究所,西安710014 [2]陕西省人工影响天气中心,西安710014

出　　处：《气候与环境研究》2012年第6期758-766,共9页Climatic and Environmental Research

基　　金：国家自然科学基金40975087;中国气象局新技术推广项目CMATG2009MS41;陕西省科技攻关项目2009K11-05

摘　　要：通过卫星多光谱资料的定标,利用可见光反射率、3.7μm和11μm辐射亮温,反演了云顶粒子有效半径、云顶温度等云特征参数。运用图像合成技术,建立了反映云宏、微观特征的RGB合成图。利用发展的多光谱云微物理综合分析方法,通过极轨卫星分析了不同过冷层状云及其降水特征,结合增雨假设,总结出适宜人工增雨作业的卫星判据为:云厚大于1.5km,云顶温度-5～-15℃时,有效半径小于25μm;或云顶温度-15～-25℃时,有效半径小于15μm。利用可见光反射率、云顶温度和有效半径多阈值建立人工增雨播云等级和分级显示。通过静止卫星跟踪云系演变,进一步确定播云部位和作业时机,指导人工增雨作业。On the basis of calibration of multiple spectral satellite data, parameters of cloud properties such as particle effective radius and temperature of cloud tops were retrieved from the reflectance of visible channel and brightness tem- perature at 3.7 μm and 11 μm wavelengths. By means of imagery compositions such as code reflectance at visible and 3.7 μm channels and a brightness temperature of 11 μm channel with primary colors of red, blue, and green （RGB）, RGB composite imagery was developed to reflect the micro- and macrophysical properties of clouds. Multiple-spectral com- prehensive methodology was used to analyze the microphysical properties and precipitation for super-cooled layer clouds via polar-orbit satellite data. On the basis of the assumption of precipitation enhancement and the analyzed results, the suitable criterion for rainfall enhancement for these types of clouds is summarized by the following parameters： Cloud thickness is greater than 1.5 km, and effective radius should be less than 25 μm when the temperature ranges between -5 ℃ and -15 ℃ and less than 15 μm when temperature is between -15 ℃ and -25 ℃. The classes of cloud seed ability for precipitation enhancement and various visual classes were established by combining the thresholds of the reflectance of visible channel, effective radius, and temperature. An example was given to illustrate the evolution of clouds tracked by FY2 data with higher temporal solution and the method in which the criteria were used to determine the timing and location for cloud seeding as a guide for operational precipitation enhancement.

关 键 词：卫星多光谱资料 过冷层状云 人工增雨 作业条件 

分 类 号：P462[天文地球—大气科学及气象学]