Compared with Beijing, why is the smog in Shanghai and Shenzhen relatively rare?

To talk about smog, we must first understand the concept and formation of smog. Haze is an air pollution state with inhalable particles, fine particles, sulfur dioxide and nitrogen oxides as the main pollutants, which occurs near the surface of the atmosphere. Fog is an aerosol system consisting of a large number of tiny water droplets or ice crystals suspended in the air near the ground, which usually occurs in autumn and winter. Haze is composed of particles such as dust, sulfuric acid, nitric acid and organic hydrocarbons in the air. The combination of the two is smog, which can make the atmosphere turbid and blur vision.

There are many high-rise buildings in the city, which can effectively reduce the wind speed, resulting in high temperature and low temperature, reducing the mobility of the air and making the atmospheric diffusion conditions worse. Suspended particles in the air are difficult to float to high altitude, which makes pollutants accumulate at low altitude, gather in a certain space, and then form smog with water molecules.

PM2.5 refers to particles with a diameter of 2.5 meters in the atmosphere, which is the chief culprit of haze weather. Sulfur dioxide and organic matter produced by burning coal in winter, industrial production waste gas, automobile maintenance and painting waste gas, waste gas produced by burning building materials production kiln, dust produced by construction sites and road traffic. These suspended pollutants react chemically in still air and become large particles, which also promotes the formation of haze weather.

After seeing the causes of smog formation, we can actually understand why the smog in Beijing is less than that in Shanghai and Shenzhen. As we all know, as far as air quality is concerned, the air in Shanghai is only better than that in Beijing, while the air in Shenzhen is much better than that in Beijing. Why? Judging from the formation conditions of smog, Shenzhen can undoubtedly be called the "smog terminator". Shenzhen is near Haibei Mountain. On the one hand, the polluted air is difficult to stay because of the wind, and the air index and other data in Beijing are really much better. On the other hand, Shenzhen is a city of parks, and its greening situation is better than that of big cities such as Beijing and Shanghai. The wind is strong and the greening is high, so the smog situation in Shenzhen is much better than that in Beijing and Shanghai.