What is the symbol of fog?

Fog is represented by three horizontal lines in the weather forecast.

When the water vapor contained in the air reaches the maximum, it reaches saturation. The higher the air temperature, the more water vapor it contains. 1 m3 air, the maximum water vapor capacity is 6.36g at 4℃; When the temperature is 20℃, the maximum water vapor content in 1 m3 air is17.30g.

If the air contains more water vapor than saturated water vapor at a certain temperature, the excess water vapor will condense out. When enough water molecules combine with tiny dust particles in the air, the water molecules themselves will combine with each other and become small water droplets or ice crystals. The water vapor in the air exceeds saturation and condenses into water droplets, which is mainly caused by the temperature drop. This is why it is foggy in autumn and winter morning.

Extended data:

Types of fog:

1, radiation fog is mostly formed in rainy weather at night, mainly because radiation cooling increases the humidity of the lower layer to saturation;

2. Advection radiation fog is mostly formed on the eve of sunny to cloudy, which is mainly caused by radiation cooling and advection humidification;

3. advection fog was formed in rainy weather with high temperature and high humidity or in the early stage of rainy weather, mainly because of the high warm and humid advection humidity.