敦煌地区2001年春季气溶胶光学厚度反演

Inversion of the Optical Depth of Aerosol over the Dunhuang Region in Spring

利用2001年春季敦煌地区CIMEL CE-318全自动太阳光度计辐射资料,反演了晴空大气、浮尘、扬沙天气条件和沙尘暴前后等不同背景下大气气溶胶光学厚度。结果表明：在不考虑吸收时,440,870 nm和1020 nm波段晴空大气气溶胶光学厚度均小于0.3;浮尘天气下的大气光学厚度约为晴空天气的2-3倍;扬沙天气大气光学厚度是浮尘天气的2-3倍;沙尘暴发生前夕大气气溶胶光学厚度将明显增加。

In this study, the optical depths of aerosol under the weather conditions of clear sky, floating dust and blowing dust and before and after sandstorm in the Dunhuang region are derived based on the data of solar radiation measured with heliograph CE-318. The results show that the optical depth of aerosol over Dunhuang is quite differ- ent under the different weather conditions in spring. If the absorption is not considered, the optical depths of clear- sky aerosol in wavebands of 440 nm, 870 nm and 1 020 nm over the study area are thinner than 0.3, the optical depths of aerosol in floating dust weather is 2 - 3 times of that in clear sky, it in blowing dust weather is 2 - 3 times of that in floating dust weather, and it is significantly increased before occurring sandstorm. Such results are of significance for the forecast and precaution of sandstorm and can be referred in monitoring and measuring environmental quality. After a sandstorm finishes, the optical depths of aerosol becomes two times thicker comparing with that in clear sky due to the effect of dust aerosol, it, however, becomes thinner gradually along with the sedimentation of dust aerosol.