Huang Zhongwei, Qi Siqi, Zhou Tian, Dong Qingqing, Ma Xiaojun, Zhang Shuang, Bi Jianrong, Shi Jinsen
Opt Express. 2020 Mar 2;28(5):7028-7035. doi: 10.1364/OE.390475.
Polarization lidar has been widely used in recent decades to observe the vertical structures of aerosols and clouds in the atmosphere. We developed a dual-polarization lidar system that can detect polarization measurements simultaneously at 355 nm and 532 nm. Dust events and haze episodes over northern China in 2014 were observed by the developed lidar. The results showed that the dust-dominated aerosol depolarization ratios at 532 nm were larger than those at 355 nm, but those of the air pollutants were smaller, indicating that this tool could provide a more accurate classification of aerosols. Moreover, we found a good relationship between the absorption coefficient of aerosols and the ratio of depolarization ratios at 532 nm and 355 nm for dust aerosols. Our results imply that aerosol absorption from polarization measurements may be determined by lidar at the ultraviolet and visible wavelengths.
近几十年来，偏振激光雷达已被广泛用于观测大气中气溶胶和云的垂直结构。我们开发了一种双偏振激光雷达系统，该系统能够同时在355纳米和532纳米波长处进行偏振测量。利用所开发的激光雷达对2014年中国北方的沙尘事件和霾天气进行了观测。结果表明，以沙尘为主的气溶胶在532纳米处的退偏振比大于355纳米处的退偏振比，而空气污染物的退偏振比则较小，这表明该工具能够更准确地对气溶胶进行分类。此外，我们发现沙尘气溶胶的气溶胶吸收系数与532纳米和355纳米处的退偏振比之间存在良好的关系。我们的结果表明，激光雷达可以在紫外和可见光波长下通过偏振测量确定气溶胶吸收情况。
