Why does the smog in the sun decrease?

After the sun comes out, the surface temperature rises, and so does the temperature near the surface. The density of hot gas is lower than that of cold gas, so the air near the surface will rise and produce convection, thus forming wind. Once the wind appears, it will blow away the smog.

Haze, as its name implies, is fog and haze. But there is a big difference between fog and haze. The aerosol system composed of dust, sulfuric acid, nitric acid and other particles in the air causes visual impairment, which is called smog. Haze is haze.

Fog is an aerosol system consisting of a large number of tiny water droplets or ice crystals suspended in the air near the ground. It mostly occurs in autumn and winter (which is also one of the reasons for the large-scale haze weather in China in June 20 13), and it is the product of water vapor condensation (or condensation) in the near-surface air. The existence of fog will reduce air transparency and worsen visibility. If the horizontal visibility of the target drops below 1000 meters, the weather phenomenon of water vapor condensation (or condensation) suspended in the air near the ground is called fog.

Haze (mái), also known as haze (smog), dust, sulfuric acid, nitric acid, organic hydrocarbons and other particles in the air can also make the atmosphere turbid. The phenomenon that the horizontal visibility of the target is 1000- 10000 meters is called light fog or mist. When fog is formed, the atmospheric humidity should be saturated (if there are a large number of condensation nuclei, the relative humidity may not reach 100%, and saturation may occur). Because the light scattered by fog composed of liquid water or ice crystals has little to do with wavelength, the fog looks milky white or bluish white and gray.

Haze weather is a state of air pollution, and smog is a general term for all kinds of suspended particles in the atmosphere, especially PM2.5 (particles with aerodynamic equivalent diameter less than or equal to 2.5 microns) is considered as the "culprit" causing haze weather. With the deterioration of air quality, cloudy days are increasing and the harm is increasing. In many areas of our country, the smog weather phenomenon is combined with fog as an early warning and forecast of disastrous weather. Collectively referred to as "haze weather".