What are the three bends in the weather forecast?

In the weather forecast, the three curved icons are dense fog.

Extended data:

Fog is a common weather phenomenon, which is composed of water droplets or ice crystals suspended in the atmosphere near the earth's surface. Fog will affect visibility and traffic. According to the international definition, the visibility in fog is less than 1 km. When the temperature reaches the dew point temperature (or near the dew point temperature), the water vapor in the air condenses to form fog. There are several different types of fog according to the cause of condensation.

When the water vapor contained in the air reaches the maximum, it reaches saturation. The higher the temperature, the more water vapor is contained in the air. 1 m3 air, the maximum water vapor capacity is 6.36g when the temperature is 4 degrees Celsius; When the temperature is 20 degrees Celsius, the maximum water vapor content in 1 m3 is17.30g.. If there is more water vapor in the air than saturated water vapor at a certain temperature, the excess water vapor will condense out. When there is enough water, it will combine with tiny dust particles in the air, and at the same time, 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.

References:

Baidu encyclopedia-dense fog