利用偏振-米散射激光雷达研究广州一次浮尘天气过程

利用偏振-米散射激光雷达、颗粒物监测仪数据,结合风廓线等气象资料分析讨论了2012年3月25日广州浮尘天气气溶胶污染事件,通过气团后向轨迹分析了沙尘气溶胶的来源及路径.结果表明本次污染过程与我国西北地区大部沙尘暴产生的浮尘远距离输送有关;浮尘期间相对湿度迅速下降,测点PM10中PM2.5所占的比例在28%~31%之间,与广州地区以细粒子污染为特征不同,本次气溶胶污染事件主要是由粗粒子引起;影响近地面的沙尘层主要分布高度在1000~2000m区域;沙尘过境期间探测到气溶胶最大退偏比为0.34.

Study of a dust case in Guangzhou using polarization mie-scattering lidar

The paper presents the systematic observational results of a dust case over Guangzhou at 25 Mar 12. The source and tracks of dust aerosol were analyzed by back-trajectory simulation. The results indicate that this pollution case has something to do with long distance transportation of sand dust storm burst out in the west of China. The relative humidity has a significant decrease during the dust case. The ratio of PM2.5 in PM10 is about 28%~31% in monitoring station. This was very different from the typical air pollution characteristics in Guangzhou region where the ambient aerosols are generally dominated by fine particles. This aerosol pollution case was caused by coarse particles. The dust layer that has an influence on the ground was mainly distributed between 1000~2000m.The maximal depolarization ratio of sand dust aerosol is about 0.34 during the dust case.