Spatial and temporal properties of a winter dust event in North China

Abstract

The optical properties, time-height distribution and particular matter from a heavy Asian dust transport episode are investigated with a synergistic ground-based, satellite sensors and transport model during 17 to 18 Nov. in 2016 in North China. There are few studies on winter dust storm, especially near the source of Asia dust storm along the transmission path. Use of the observation data from the ground-based instruments and satellite, this paper reports the evolution process of the severe dust event in winter in North China. In winter, the Taklimakan desert is the most important source of Asia dust storm. The floating height of most of dust aerosol is less than 2.5 km above ground level, and it is transported along relatively fixed ‘dust corridor’. After passing through the Loess Plateau, dust particles deposition accelerates since lack of transmission power caused by the decrease of west wind speed and the blockade from the reverse wind. As an example, the air quality has dropped to the level of haze pollution. With maximum PM10 mass concentrations above 4400 μg·m−3 in Wuwei city (a typical observation City). In addition, we also analyze the transport characteristics of dust as well as the change features of weather and meteorological elements. The possible transformation of the dust particles into cloud condensation nodules may appear due to the increase of air temperature and humidity in East China. The wet deposition probably is another reason to prevent the spread of fine dust particles with higher floating height. Above conclusions may reveal why East China is rarely subject to dust storms in winter.