Abstract: The optical properties and vertical distribution of dust aerosol during a dust process over northern China in spring of 2018 was analyzed using satellite data. At the same time, the impact of dust weather on the concentration of particulate matter and air quality was analyzed by using ground station data. Finally, the mechanism of dust weather on the concentration of particulate matter was analyzed by using different levels (surface, 500 hPa and 700 hPa) of geopotential height field and wind field data. The results show that:(1) The AOD, AAOD and AI were over 0.4, 0.035 and 1 in northern China from March 27 to 30, 2018, respectively. The dust aerosol was mainly distributed in the range of 8 km from the ground, and the volume depolarization ratio was mostly between 0.06 and 0.4, and the color ratio is between 0.6 and 1.2. (2) The concentration of particulate matter in each city changed due to the influence of dust weather to some extent. The average values of PM_2.5 and PM₁₀ were 4.1 times and 4.3 times of the national first-level standard from March 27 to 28. The average values of PM_2.5 and PM₁₀ were 3.5 times and 3.4 times of the national first-level standard from March 29 to 30. On the 28th, PM₁₀/PM_2.5 reached the highest of four days in Zhangjiakou, Hebei Province, with a maximum ratio of 10.9. (3) The strengthening and southward of the Baikal high pressure at the low level was one of the most important weather systems for the dust emission in the southwestern part of Inner Mongolia and the Hexi Corridor; the surface cyclone and low-level shear in the Hetao area were the key factors for the dust emission in the western part of North China; The high-pressure ridge in the Okhotsk Sea area and the low-pressure system on the ground in the northeastern China were helpful to the dust emission in the northeast China.

Key words: dust aerosol, air quality, particulate matter, weather system