沙尘天气中气溶胶光学特性的时空分布特征

Spatial-temporal Distribution of Aerosol Optical Properties during Sand-dust Weather Processes

选取内蒙古境内额济纳旗、乌拉特中旗、东胜、朱日和、锡林浩特5个站的几次沙尘天气过程和晴朗天气下CE-318太阳光度计资料,计算出大气气溶胶光学厚度,结合气象资料分析在沙尘天气发生过程中气溶胶光学厚度的时空分布特征。分析结果显示,在沙尘天气发生过程中,气溶胶光学厚度是一个相当敏感的变量,其随沙尘的发生、发展和消亡表现出明显不同的日变化特征,且光学厚度值随着沙尘天气的发生和发展,在其空间分布变化上与沙尘天气本身的空间分布变化具有很好的一致性,可以很好的反映沙尘输送过程。此外气溶胶光学厚度与大气稳定度也有一致的日变化趋势。因此,对于大气气溶胶光学厚度的监测可以为沙尘天气的预报提供较为准确的客观依据。

The atmospheric aerosol optic depth （AOD） were calculated from the Sun Photometer observed data at Ejinaqi, Wuzhongqi, Dongshen, Zhurihe and Xilinhot stations in Inner Mongolia. The AOD data and the meteorological data were used to analyze the spatial-temporal distribution of AOD during sand-dust weather processes. Analyzing result showed that AOD is a very sensitive parameter, having distinct diurnal changing characteristics along with the forming, developing and ending processed of sand-dust weather; the spatial distribution of AOD was consistent with that of sand-dust weather, well reflecting the processes of sand-dust transporting. Besides, the diurnal change of AOD has the same tendency as that of the atmospheric stability. Therefore, the atmospheric AOD can provide comparatively accurate objective basis for forecasting the sand-dust weather.