淮北地区一次春季浮尘天气成因研究

Study on forming reasons for a spring dust weather in Huaibei Region

利用激光气溶胶雷达和风廓线雷达,结合卫星遥感资料、地面气象要素资料、大气气溶胶浓度资料和HYSPLIT模型,研究了2017年5月5-8日淮北地区一次沙尘天气过程的特征.结果表明,2017年5月5-6日上午的浮尘(过程1)是由西北-华北地区的远距离输送所致,其中PM10峰值浓度高达766 μg·m^-3,而6日下午-7日的浮尘(过程2)是冷空气回流所导致.外源输入、气象要素和垂直风场的变化为浮尘天气的发生和维持创造了有利条件,降水的出现使本次浮尘天气过程结束.激光气溶胶雷达可以有效监测此次浮尘天气的大气气溶胶消光系数的空间分布,能直观准确地反映出污染物的分布聚集情况以及时空变化,对大气污染监测具有重要意义.本研究还提出了适合江苏地区的浮尘客观判定方法,SO2/PM10、NO2/PM10以及PM2.5/PM10的比值可以有效判别浮尘天气.

Using lidar and wind profiler radar, combined with satellite remote sensing data, ground meteorological element data, atmospheric aerosol concentration data, and HYSPLIT model, a dust weather process in Huaibei region on May 5-8, 2017 were analyzed. The 1st dust process (from May 5 to morning of May 6, 2017) was caused by long-distance transportation from the northwest and north China, where the peak concentration of PM10 was as high as 766 g·m^-3.The second dust process (from the afternoon of May 6 to 7, 2017) was caused by the flow back cold air. Dust transmission input, meteorological elements, and vertical wind field variation create favorable conditions for the occurrence and maintenance of the dust weather. The appearance of precipitation ended the process of dust weather. Lidar can effectively monitor the spatial distribution of atmospheric aerosol extinction coefficient in this dust weather, and can directly and accurately reflect the distribution and aggregation of pollutants as well as spatial and temporal changes, which is of great significance for atmospheric pollution monitoring. This study also puts forward a suitable method for the objective determination of dust in Jiangsu province. The ratios of SO2/PM10, NO2/PM10, and PM2.5/PM10 can be used as a quick index for judgment of dust event.