西北地区空中云水资源的时空分布特征

Temporal and Spatial Distributions of Cloud Water Resources over Northwestern China

利用1983年7月至1998年12月国际卫星云气候计划ISCCP D2的月平均云资料,对西北地区空中云水资源的时空分布特征进行了系统的研究.结果表明:三个不同区域的月平均总云量、 光学厚度和云水路径的区域平均值分别在52.5%～58.3%,2.6～6.6和 44.9～77.6 g·m-2之间;西北地区空中云水资源多年平均分布有其沿地形分布的特点,总云量、中云量、总光学厚度和总云水路径的高值区均在天山、昆仑山、祁连山一带,而低值中心一般分布在塔里木盆地-内蒙古西部戈壁沙漠-黄土高原西北部一带.此外,祁连山、青海所在的高原气候区云水资源近年呈上升趋势,特别是总光学厚度和总云水路径15年来呈明显上升趋势,分别约上升了0.8和16.4 g·m-2.

The temporal and spatial characteristics of cloud water resources over Northwestern China have been analyzed using the ISCCP （International Satellite Cloud Climatology Project）monthly mean D2 data from July 1983 to December 1998. The Northwestern China has been divided into three climatical regions in this study. The results show that the regional averaged total cloud amount, optical thickness and water path are between 52.5%-58.3%, 2.6-6.6 and 44.9-77.6 g · m^-2, respectively. The major feature of spatial distribution resources that higher value areas of cloud properties are all over Tianshan Mountains, Kunlun Mountains and Qilian Mountains, while the lower values of cloud properties locate over Tarim Basin, the western desert of Inner Mongolia and the northwestern part of Loess Plateau. The cloud properties also show an increasing tendency during recent years over the Plateau climatical region which includes Qilian Mountains and Qinghai province. In particular, the optical depth and water path have risen 0.8 and 16.4 g · m^-2 in the 15 years, respectively.