What's the difference between fog and smog?

There are many ways to distinguish fog from haze. We can distinguish fog and haze from the following points:

First of all, in terms of its material content:

1, the water content of fog is higher than that of haze. Generally, the water content of fog is above 90%, and the water content of haze is below 80%. Between these two values is what we usually call smog.

2. Their forming substances are different. Fog is formed by water vapor, but haze is formed by some dust, smoke and some salt particles. From this perspective, we can know that fog is harmless and haze is harmful. However, whether it is fog or smog, it has a certain impact on traffic, so pay attention to safety when traveling.

Second, in terms of color and visibility (visible to the naked eye):

1, the colors of fog and haze are very different. The color of fog is generally milky white or bluish white, which looks very fresh and clean. The color of smog is yellow or orange-gray, which is because the color formed by dust particles floating in the air is seriously polluted at first glance, and it will have adverse effects if inhaled by the human body.

2. They can be distinguished from each other in visibility. When fog or haze strikes, if you can see things within the horizontal range of 1 km and the air is clean, it is proved to be fog. Usually, the horizontal visibility of fog is between 1- 10 km; And if the horizontal visibility is less than 1 km and the air is turbid, it is smog.

To sum up, what we can see with the naked eye, if the color is milky white or green Baise, is the fog that can see things within one kilometer of the level. If the color is cloudy yellow or orange-gray, and nothing can be seen within one kilometer in the horizontal direction, then it is smog.