From 11 to 10 April, a wide range of sand and dust weather occurred in Beijing. The primary pollutant in Beijing is inhalable particulate matter (hereinafter referred to as PM9), and the air quality is serious pollution.
Beijing Meteorological Observatory upgraded to issue a yellow warning signal for sandstorms at 10 o'clock on the 20th. The minimum visibility in most areas is less than 1000 meters. In March this year, there were frequent sand and Dust weather, mainly related to the deviation of surface conditions in the sand source area.