What is the cause of haze weather?

Smog is very common in cities. Fog and smoke, as a disastrous weather phenomenon, are used as early warning and forecasting in many areas of China, collectively referred to as haze weather. Haze is the result of interaction between human activities and specific climatic conditions. Every year, the key word is 20 13 fog. From June 5438 to this year 10, there were four smog processes in 30 provinces (autonomous regions and municipalities) in Beijing, of which only five days were not foggy days. It is reported that less than 65,438+0% of the 500 big cities in China meet the air quality standards recommended by the World Health Organization. The National Disaster Reduction Office and the Ministry of Civil Affairs first listed the smog weather that is harmful to health in the 20 13 natural disaster notification, which was on June 4, 20 14. During an inspection tour in Beijing in February, 20 14, it was pointed out that the first task to deal with smog pollution and improve air quality is to control carbon monoxide emissions, and major measures should be taken from the aspects of compressing coal burning, strictly controlling vehicles, adjusting industries, strengthening management, joint prevention and control, and managing according to law. The reasons for the foggy weather are as follows: First, the relative humidity of the air near the ground in these areas is relatively high, and the dust on the ground is stirred up by people and cars; Second, there is no obvious cold air activity, the wind is small, the atmosphere is relatively stable, and the tiny particles in the air gather and float in the air because the air does not flow; Third, cloudy skies are conducive to radiation cooling at night, so that air with high humidity near the ground is saturated and condensed to form fog; Fourth, the lower the temperature, the higher the temperature, and the fewer clouds, so the fewer clouds are formed.