What is the reason for the smog weather in the Middle East of China?

The similarity between fog and haze is sight distance obstacle. However, the reasons and conditions for the formation of fog and haze are quite different. Fog is a large number of tiny water droplets or ice crystals floating in the air, and the formation conditions should have a high water vapor saturation coefficient. When fog appears, the relative humidity of air often reaches 100% or approaches 100%. With the daily change of air humidity, fog is more common or thicker in the morning and evening, and it becomes lighter or even disappears during the day. The effective horizontal visibility is less than 1KM in fog. When the effective horizontal visibility is 1- 10km, it is called light fog.

"There is actually a difference between fog and haze." Sun Leng, a senior engineer in the Climate System Monitoring Office of the National Climate Center, pointed out that fog refers to the weather phenomenon when the visibility is lower than 1 km due to the condensation of suspended water vapor in the atmosphere. The formation of smog is mainly the result of the interaction between a large number of particles suspended in the air and meteorological conditions, and its causes are three:-the phenomenon of increasing static wind in the horizontal direction. The higher the buildings are built in the city, the obstruction and friction of airflow passing through the urban area will be obviously weakened. The increase of static wind phenomenon is not conducive to the diffusion and dilution of suspended particles in the atmosphere, and it is easy to accumulate around urban areas and suburbs; -There is an inversion in the vertical direction. The inversion layer is like a pot cover over a city. This inversion phenomenon that the upper air temperature is higher than the lower air temperature limits the vertical movement of the lower air, making it difficult for suspended particles in the air to drift to the upper air and be blocked at the lower air and near the ground. The increase of suspended particles in the air. With the growth of urban population and industrial development, the number of motor vehicles has soared, and the emissions of pollutants and suspended solids have increased greatly, which directly leads to the decline of visibility. In fact, dust "smog" will also occur in home decoration, and indoor dust is pervasive, which is not only harmful to the health of staff and users, but also increases the cleaning burden. When the dust is serious, it will also bring many hidden dangers to the decoration project.