1999-2003年我国气溶胶光学厚度的变化特征

利用我国70站1999-2003年1月、4月、7月、10月月平均水汽压和能见度资料，反演得到各站大气气溶胶光学厚度（AOD，aerosol optical depth），分析了气溶胶光学厚度的变化特征。结果表明：中国多年平均大气气溶胶光学厚度的分布是以四川盆地为中心向四周减少，长江中下游和广东沿海为两个次大值中心，而东北和西北大部分地区以及云南等地AOD较小；各季节AOD的空间分布都有所不同；近5aAOD有弱增加趋势；月平均气溶胶光学厚度与能见度有较好的负相关关系。

Characteristics of Atmospheric Aerosol Optical Depth over China during 1999-2003

Aerosol optical depths（AOD） were retrieved by using the vapor pressure and visibility data over 70 stations in China from 1999 to 2003 ,then its statistical characteristics were analyzed. It is found there Sichuan Basin was the maximum area of yearly mean AOD, and another two large value centers were in the middle and lower reaches of Yangtze River and the coastal area of Guangdong, but AOD was lower in the Northeast China and Northwest China and Yunnan. The distribution of AODs for each month was similar, but differences were also obvious. During 1999--2003, the national average AOD showed a weakly increasing. The monthly average AOD had a close negative correlation with visibility.