基于激光云高仪的雾霾光学特性研究

利用2016年10月~2017年2月激光云高仪资料，分析了霾、雾、轻霾、轻雾、晴空等天气后向散射强度廓线特征，通过统计各高度层后向散射强度、后向散射强度垂直梯度的概率分布，分析了多种天气的气溶胶光学特性。结果表明：雾天气后向散射强度较霾天气大，雾厚度一般不超过300m。霾天气后向散射强度随着高度的增加减小缓慢，霾的厚度大于500m。与雾和轻雾相比，霾和轻霾天气垂直梯度绝对值取小值的概率较大。雾和轻雾天气400m高度以上垂直梯度绝对值较小，400m高度以下数值较大。由于霾区内粒子分布较均匀，雾区粒子分布起伏明显，雾区内后向散射强度忽大忽小，所以雾天气垂直梯度绝对值出现大值的概率较霾天气高。

Study of distinction between haze and fog based on ceilometer

Based on the data of Vaisala CL51 ceilometer observed from October 2016 to February 2017 by the Beijing Daxing station, we studied the backscattering profile characteristics of many different kinds of weather, the probability distributions of backscattering data and backscattering data gradients at different heights are calculated. Our results show that the backscattering date in the fog layer increase first and then decrease with the increase of height. Backscattering data in fog days is larger than that of haze days, thickness of fog is generally less than 300m. Backscattering data in haze days decrease slowly with the increase of height, and the thickness of haze is greater than 500m. Compared with fog days and mist days, the probability of small vertical gradient of backscatter data in haze days and light haze days is greater. The vertical gradient value of backscatter data in fog days and mist days above the height of 400m is small, while the value below 400m is large. Due to the uniform distribution of particles in the haze region, the distribution of particles in the fog region is obviously fluctuant, therefore the probability of large values appearing in the vertical gradient in fog weather is higher than that in haze weather.