中国地区云量和云光学厚度的分布与变化趋势

Distribution and Variation Trends of Cloud Amount and Optical Thickness over China

利用最新的1983～2009年国际卫星云气候计划（ISCCP）D2月平均资料集,得到了中国地区总云量、低云量、中云量、高云量与云光学厚度的分布与变化趋势,结果表明：中国总云量和中云量呈现南多北少的分布,青藏高原地区高云量较大而低云量很小;总云量和中云量在东部呈增加趋势,西部呈减小趋势,低云量和高云量在大部分地区呈减小趋势。从不同季节来看,春季和秋季北方总云量增加,西部总云量减小;夏季大部分地区总云量增加,冬季大部分地区总云量减少。云的光学厚度呈现南多北少的分布,且在大部分地区呈增加趋势。同时利用中分辨率成像光谱仪（MODIS）资料分析了2001～2013年间中国不同污染地区总云量与云光学厚度的分布及变化趋势的异同,结果表明：中国不同污染地区云量与云光学厚度呈现不同的分布和变化规律。

The distribution and variation trends of cloud amount and optical thickness over China were analyzed by using the monthly mean data of International Satellite Cloud Climatology Project（ISCCP） D2 from 1983 to 2009.Results show that the total cloud and middle cloud amounts are large in southern China and small in northern China.In Qinghai-Tibet Plateau there are large high cloud amount but smaller low cloud amount.The total and middle cloud amounts increased in eastern China and decreased in western China during the mentioned period,but the low and high cloud amounts decreased in most areas of China.Seasonally,the total cloud amount increased in the north and decreased in the west in spring and autumn,while it increased in most areas in summer and decreased in winter.The cloud optical thickness,which is larger in southern China than in northern China,increased in most areas.Additionally,the differences in the distribution and trends of cloud amount and optical thickness between heavily and less polluted areas were discussed by using Moderate Resolution Imaging Spectroradiometer（MODIS） data from 2001 to 2013.It is shown that the distribution and trends of cloud amount and optical thickness over differently polluted areas of China have different characteristics.