When smog strikes, how to determine the early warning level initiated by various places?
Why is the smog "early light and late heavy"?
Guo, chief forecaster of Beijing Meteorological Observatory, said that the reason why people feel that smog is "light in the morning and heavy in the evening" is mainly because there is weak cold air infiltration affecting Beijing at night on 16 and 17. Under the influence of weak northerly winds, the concentration of pollutants in Beijing decreased from midnight to the next morning, and the air quality and visibility in the morning were slightly better. Please click >>
Where did the smog go after it was blown away?
Wind and rain can usually disperse haze and fog. Precipitation will purify the air, which is called wet deposition in meteorology. Rain or snowflakes wash the dirty things in the air to the ground, reduce the concentration of pollutant particles suspended in the air, and let the smog enter the ground. So after the rain and snow, the air is fresh. Wind is the power to make the air active.
In short, cold air came, static conditions were broken, PM2.5 was greatly diluted, and fog and haze dissipated. Please click >>
How to determine the early warning level initiated in various places?
This year, the Ministry of Environmental Protection promoted the unified early warning standard for Beijing-Tianjin-Hebei, and has achieved the unified early warning grading standard for heavy polluted weather in Beijing-Tianjin-Hebei and some cities in Henan and Shandong. According to the Beijing-Tianjin-Hebei unified early warning classification standard, it is estimated that the air quality may reach severe and above pollution for four consecutive days, and serious pollution may occur for more than two days, reaching the red warning threshold; It is estimated that the air quality may reach severe pollution or above for three consecutive days, and serious pollution may occur 1 day, reaching the orange warning threshold.