基于微脉冲激光雷达计算整层大气气溶胶光学厚度

Calculation of Whole Atmospheric Aerosol Optical Depth Based on Micro-Pulse Lidar

基于微脉冲激光雷达测量数据,提出了利用气溶胶标高计算整层大气气溶胶光学厚度(AOD)的算法。首先利用激光雷达垂直和水平测量数据分别反演得到气溶胶垂直消光系数廓线和近地面水平方向的消光系数;然后将气溶胶垂直消光系数廓线分为4种类型,分别按照不同的方法拟合得到气溶胶标高;最后将气溶胶标高与近地面消光系数相结合,可得到整层大气AOD。将计算结果与同一地区相同时刻太阳光度计的测量结果相比较,发现二者具有较好的一致性,平均相对误差不超过6.7%。所提方法为白天少云和夜晚时段大气AOD的反演提供了一种新的技术手段。

An algorithm is proposed to calculate the whole atmospheric aerosol optical depth（AOD）with aerosol scale height based on micro-pulse lidar data.Vertical extinction coefficient profiles and surface horizontal extinction coefficient of aerosol can be retrieved with the data vertically and horizontally measured by lidar.The vertical extinction coefficient profiles of aerosol are classified into four types,and different fitting methods are utilized to obtain aerosol scale height.Aerosol scale height is combined with surface extinction coefficient to calculate the whole atmospheric AOD.Comparison is made between the calculated results and those measured by sun-photometer in the same area simultaneously,and we find that the compared results show a good agreement.The average relative error is less than 6.7%.The proposed method provides a new technological means to calculate atmospheric AOD during the partly cloudy conditions and the night.