Based on the observations of a micro-pulse lidar in Beijing, the MLH is retrieved by using the artificial assistance algorithm during the day from 2016 to 2019. Then the seasonal and diurnal variations of MLH and its relationship with PM_2.5 mass concentration are analyzed. The results show that the MLH shows obvious seasonal and diurnal changes, and the daily averaged MLH is significantly higher in spring than that in other seasons. The daily maximum MLH height in every year occurs in May of the year. The variation trend of the MLH is opposite to the concentration of PM_2.5 from 08:00 am to 03:00 pm. Through linear fitting of the data, it is shown that the negative correlation is stronger when the ventilation index and wind speed are induced. When considering the influence of wind direction, the MLH has a stronger negative correlation with PM_2.5 in the case of southwesterly wind. In addition, after weather classification, the correlation between PM_2.5 and the MLH in each same weather group can be significantly improved.

利用微脉冲激光雷达观测资料, 运用人工辅助算法, 获得2016―2019年白天混合层高度(MLH), 并分析其变化特征及其与空气污染物PM_2.5浓度的关系。结果表明, 混合层高度表现出明显的季节变化和日变化, 春季高度明显大于其他季节, 最大值均发生在 5月。混合层高度在08:00―15:00 BJT的变化趋势与PM_2.5浓度负相关。线性拟合结果表明, 当考虑风速的影响时, 通风指数与 PM_2.5具有更强的负相关关系; 当考虑风向的影响时, 西南风情况下, 混合层高度与PM_2.5具有更强的负相关关系。对天气分型后, 每个天气类型的PM_2.5浓度与混合层高度的相关性更加显著。