What's the difference between fog and haze?

What's the difference between fog and haze?

We often say that once it is fog, in fact, fog is fog and haze is haze. What's the difference between fog and haze?

Fog is a natural phenomenon, which is a visible aggregate of a large number of tiny water droplets (or ice crystals) suspended in the atmosphere near the ground.

Haze, also known as haze, is mainly caused by human factors. It is caused by dust, sulfuric acid, nitric acid, organic hydrocarbons and other particulate matter in the air, which makes the atmosphere turbid, blurred vision and poor visibility.

The difference between fog and haze mainly includes:

1. Visibility range is different. The horizontal visibility of fog is less than 1km, and that of haze is less than 10km.

2. The relative humidity is different. The relative humidity of fog is more than 90%, haze is less than 80%, and the relative humidity is between 80 and 90%. It is a mixture of haze and fog, but its main component is haze.

3. The thickness is different. The thickness of fog is only about tens of meters to 200 meters, and the thickness of haze can reach about 1-3 kilometers.

4. The boundary features are different. The boundary of fog is very clear, and it may be clear in Wan Li after passing through the "fog area", but there is no obvious boundary between haze and clear sky.

5. Different colors. The colors of fog are milky white and bluish white, while haze is yellow and orange gray.

6. The changes are different every day. Fog is most likely to appear from midnight to early morning; The diurnal variation characteristics of haze are not obvious. When the air mass changes little and the air mass is stable, it lasts for a long time.

Conditions for generating smoke:

Smog is often accompanied by smog. Once a large range of smog weather is formed, it can last for several days under favorable weather conditions. The weather conditions conducive to maintaining smog include: first, the wind is small, which is not conducive to the horizontal diffusion of pollutants; Second, the low-altitude atmospheric stratification is stable, and the inversion layer is easy to appear near the ground, which is not conducive to the vertical upward diffusion of pollutants and makes pollutants accumulate in the atmospheric boundary layer.