What causes the smog?

Fog: Fog is an aerosol system composed of a large number of tiny water droplets or ice crystals suspended in the air near the ground, and it is the product of condensation (or sublimation) of water vapor in the air near the ground.

Haze: Dust, sulfuric acid, nitric acid, organic hydrocarbons and other particles in the air can also make the atmosphere turbid, blur the vision and make the visibility worse. If the horizontal visibility is less than 65,438+00,000 meters, the visual distance obstacle caused by this aerosol system composed of non-aquatic products is called haze or dust haze.

The reason for the formation is that sulfur dioxide, nitrogen oxides and inhalable particles are the main components of smog, the first two are gaseous pollutants, and the last particle is the culprit that aggravates smog weather pollution. They combine with fog and instantly turn the sky gray.

There are three main reasons:

First, the relative humidity of the air near the ground in these areas is relatively high;

Second, there is no obvious cold air activity, the wind is small, and the atmospheric stratification is relatively stable;

Third, the sky is clear and partly cloudy, which is conducive to radiation cooling at night and makes the near-surface air with relatively high humidity saturate and condense to form fog.