被动多轴差分吸收光谱大气气溶胶光学厚度监测方法研究

Determination of the atmospheric aerosol optical density by multi axis differential optical absorption spectroscopy

介绍了基于太阳散射光的被动多轴差分吸收光谱(MAX-DOAS)技术在大气气溶胶光学厚度(aerosol optical density,AOD)监测中的应用.MAX-DOAS根据氧的二聚物(O4)在紫外、可见波段的特征吸收来确定气溶胶参数,实验中利用测量得到的O4在360nm处斜柱浓度,并结合O4垂直柱浓度基本稳定等信息,在选取合适的气溶胶单次散射反照率、非对称因子及其廓线形状等条件下,基于大气辐射传输模型采用迭代算法解析出大气气溶胶光学厚度.经过与太阳光度计(CE318)测量结果的对比,两者相关性达到87%.

In this work,a method to determine atmospheric aerosol optical density from multi axis differential optical absorption spectroscopy（MAX-DOAS） observations was described.It basically utilizes the differential absorption structures of the oxygen collision complex（O4） in the UV and visible wavelength regions to derive information on aerosol optical properties.Based on radiative transfer model with appropriate aerosol single scattering albedo,asymmetry parameter and profile,atmospheric aerosol optical density was retrieved in an iterative process by comparison with measured O4 slant column densities at 360 nm.The retrieved value was verified through comparisons with sun photometer CE318.