祁连山区云光学特征的遥感反演与云水资源的分布特征分析

利用Terra和Aqua卫星上载的MODIS探测器接收资料和祁连山区及周边气象台站6 h降水量资料,应用6S辐射传输模式和Mie模式,针对2002—2005年以来的18次大范围云覆盖的祁连山区,反演了云的光学厚度、云粒子有效半径以及云液态含水量等参数,结合地理信息系统分析了其随海拔高度变化的分布特征及其与地面降雨量的关系.结果表明:祁连山区云的光学厚度、云粒子有效半径以及云液态含水量分布受地形影响具有显著的地域差异,最大值分布在海拔4 300 m以下的山区,是云水资源丰富区和易降水区;云宏观特征参数与地面6 h降水量成正相关关系,产生降水概率较大的云光学厚度在8~20之间,云粒子有效半径在6~12μm之间,云液态含水量在0.04 g·m^-3就能产生降水.祁连山区云液态含水量可高达0.15 g·m^-3,表明山区云水资源具有很大的开发潜力.

Remote Sensing Retrieval and Analysis of Optical Character of Cloud in Qilian Mountains

By using MODIS data from Terra and Aqua satellite,6 hours precipitation data of 18 cases from 2002 to 2005,applying 6S Model and Mie Model,some parameters,including optical thickness of cloud,efficient radius of cloud particle and content of liquid water,are retrieved.Their special distributions are also analyzed by combining with GIS software.Then,the relation of all those parameters and 6 hours precipitation are analyzed.The results show that there is a striking dissimilarity in special distribution of the optics thickness and efficient radius of cloud particle,which is influenced by terrain,with a maximum on the south slopes lower than 4 300 m of the mountains,a region with rich resources of cloud water.There are positive correlation between precipitation and the three parameters.Precipitation probability is large when optical thickness changes from 8 to 20,efficient radius of cloud particle changes from 6 to 12 μm and content of liquid water is more than 0.04 g·m^-3.Content of liquid water higher than 0.15 g·m^-3 at 4 300 m a.s.l.shows that there is a large potential to exploit cloud water in the Qilian Mountains.