Abstract:Based on the meteorological and air quality data in the autumn and winter of 2015-2018, PM10, PM2.5 and other pollutants during dust events in North China are analyzed, and the transport paths of dust are classified. The results suggest that the transport paths of dust are closely related to the upper-level winds at 500 hPa and 850 hPa. Three types of dust are identified according to the transport paths, namely the Eastward Diffusion type, the Southeast Transport type and the Northeast Transport type, which account for 38.9%, 38.9% and 22.2% of the statistics, respectively. The intensity and influence range of the dust of the Eastward Diffusion type are the largest, and the average mass concentration of PM10 and PM2.5 in North China are 156.4 μg·m-3 and 86.1 μg·m-3. The dust of the Southeast Transport type dissipates rapidly with low intensity due to the high wind speed in North China, and the pollution in North China is the lightest among the three types. The average mass concentration of PM10 and PM2.5 are 171.9 μg·m-3 and 117.8 μg·m-3 in North China during the Northeast Transport type, which is the most serious pollution among the three types. The lower wind speed and downdraft in North China may lead to the accumulation of pollutants. Moreover, the average relative humidity during the Northeast Transport type in North China is 4%-5% higher than that during the other two types, and especially in the coastal areas, the relative humidity is higher than 70%, which may promote the heterogeneous formation of secondary particles and aggravate the pollution.