用CE-318太阳光度计资料研究银川地区气溶胶光学厚度特性

Optical Depth Characteristics of Yinchuan Atmospheric Aerosols Based on the CE-318 Sun Tracking Spectrophotometer Data

根据CE-318数据,利用Bouguer定律计算了银川地区的大气气溶胶光学厚度,并分析其变化特征。结果表明,该地区大气气溶胶光学厚度具有明显的日变化和季节变化。日变化有4种类型:1)变化相对稳定;2)整体上呈上升的趋势;3)早晚小,中午大;4)早晨09—11时出现峰值,其他时间变化较小。季节变化则是冬、春季节大,秋季次之,夏季最小;春季大气中的主要成分是沙尘,冬季大气的主要成分是人类活动排放的颗粒物,夏季由于降水多,气溶胶数浓度较低,气溶胶光学厚度较小。

By using the direct solar radiation data measured by a CE-318 automatic sun tracking spectrophotometer,the optical depth of atmospheric aerosols is calculated by using the Bouguer theorem and its variational characteristics in four seasons in Yinchuan area are analyzed.The results show that the optical depth of atmospheric aerosols shows apparently daily and seasonally variations.There are four patterns of daily evolution(0900—1600) BST,and they are:1)the diurnal evolution of the optical depth of atmospheric aerosols are relatively steady;2)the diurnal evolution of the optical depth of atmospheric aerosols shows a general trend of increase;3)the optical depth of atmospheric aerosols exhibits a peak value at noon;4)the optical depth of atmospheric aerosols shows a peak value in the morning but its variation is small at other time.The seasonal variation of the optical depth is larger in winter and spring,smaller in autumn and the smallest in summer.The main component of atmospheric aerosols is dust in spring,and the particles emitted by human beings in winter.As far as in summer, the optical depth and number concentration of atmospheric aerosols are relatively small because of the abundance of precipitation and the plenty of water vapor.