What is smog? Where are you from?

Haze (w' máI) is a combination of fog and haze. Because of the deterioration of air quality, the phenomenon of smog weather has increased significantly and the harm has increased. In many areas of China, haze weather phenomenon is combined with fog as an early warning and forecast of disastrous weather. Collectively referred to as "haze weather". In case of foggy weather, try to take anti-virus measures.

Haze, fog, haze. But fog is fog, haze is haze, and the difference between fog and haze is very big.

Haze means haze. Dust, sulfuric acid and nitric acid in the air can cause vision damage. The difference between haze and fog is that the relative humidity is small when haze occurs, but it is saturated in fog (if there are a large number of condensation nuclei, the relative humidity may not reach 100%, and saturation may occur).

First, sulfur dioxide, nitrogen oxides and inhalable particles are the main components of smog. The first two are gaseous pollutants, and the last particulate matter is the chief culprit that aggravates smog weather pollution. They combine with fog and instantly turn the sky gray. The abbreviation of particulate matter is PM, and what Beijing monitors is fine particulate matter (PM2.5), that is, pollutant particles with a diameter less than or equal to 2.5 microns. This particle itself is not only a pollutant, but also a carrier of toxic substances such as heavy metals and polycyclic aromatic hydrocarbons.

Second, the sources of toxic particulate matter in cities: First, automobile exhaust. Cars that use diesel are emitting exhaust gas.

Hazy weather pictures (6 photos)

Fine-grained "recidivist". Small cars that use gasoline emit gaseous pollutants, such as nitrogen oxides, which are easily converted into secondary particulate pollutants in foggy days, aggravating smog.

Fog is an aerosol system composed of a large number of tiny water droplets or ice crystals suspended in the air near the ground, which often appears in autumn and winter (which is also one of the reasons for the large-scale haze weather in China in June 20 13), and is the product of water vapor condensation (or condensation) in the air near the ground. 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. 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 is composed of particles such as dust, sulfuric acid, nitric acid and organic hydrocarbons in the air. It will also make the atmosphere turbid, blur the vision and worsen the visibility. If the horizontal visibility is less than 65,438+00,000 meters, the sight distance obstacle caused by this non-aqueous aerosol system is called haze or dust haze, and the Hong Kong Observatory calls it haze.