Abstract:

From March 27 to 28, 2018, a large-scales and-dust event occurred in central and eastern Inner Mongolia, Northeast China, and North China. In the early morning of March 28, massive dust particles arrived in Beijing, causing severe air pollution in the city. In this study, we analyzed the characteristics of the atmospheric boundary layer, the source of sand and dust, and the features of air pollution during this sandstorm event, using surface routine observation data of China Meteorological Administration, retrieved data from aerosol lidar and wind profiler radar, and atmospheric composition data from the Ministry of Ecology and Environment of the People's Republic of China. The results indicated that the depolarization ratio of dust aerosols during this dusty weather in Beijing is about 0.25-0.40. The depolarization radio data show that sand particles entered Beijing from a high altitude, about 6 h earlier than entering from the ground. These sand particles affecting Beijing mainly come from the north, and sand particles from the east have a certain supplement. During this event, the concentrations of Ca, Fe, Na, K, Mn, and other elements in Beijing increase significantly, which are equivalent to the abundance of the substance in the crust. The concentrations of pollutant elements such as Cu, Zn, Pb, Cd and As decrease, and they are much higher than the abundance of the substance in the earth's crust.

Key words: Atmospheric boundary layer, Lidar, Depolarization ratio, Atmospheric composition