Who told me about the change in the fog dissipation! Positive and urgent

This is mainly determined by the humidity, temperature and suspended solids in the air, as well as the speed of the air.

When the air close to the ground cools to a certain level, the water vapor in the air will condense into fine water droplets and float in the air, reducing the visibility at ground level, a weather phenomenon called fog.

Causes Saturation is reached when the water vapor contained in the air reaches its maximum. And the higher the temperature, the more water vapor can be contained in the air. 1 cubic meter of air, when the air temperature is 4, the maximum amount of water vapor that can be contained is grams; When the air temperature is 20, the maximum amount of water vapor that can be contained in 1 cubic meter of air is grams.

If the air contains more water vapor than the amount of saturated water vapor at a certain temperature, the excess water vapor will condense and when enough water molecules combine with the tiny dust particles in the air, and the water molecules themselves will bond to each other, becoming small water droplets or ice crystals. The amount of water vapor in the air exceeds the saturation amount and condenses into water droplets, which is mainly caused by the drop in air temperature.

If the heat of the ground is lost, the temperature drops, and the air is quite humid, then when it cools to a certain extent, a part of the water vapor in the air will condense and become many small water droplets, suspended in the air layer near the ground, and fog will be formed.

As for the fog dissipation, it is natural that the above conditions cannot be met, such as the temperature rises, the airflow speed increases, the humidity drops and so on.

Water vapor in the sky?

Fog usually forms at night and gradually disappears after early morning. Sometimes, however, people see such fog, which is formed at night and does not dissipate during the day, and sometimes even rains. Why?

Most of the fog that does not disperse during the day is related to frontal crossings. Before the warm front crosses, fog often occurs. Above this fog, there are thick rain clouds, and small raindrops that fall at the bottom of the rain clouds evaporate below the cloud base and condense near the ground, which is why the fog in front of the front is formed.

Since there are thick rain clouds on the top of this fog, the sun cannot penetrate in large quantities, and the conditions for producing fog continue to exist, so of course such fog will not disperse. When the water vapor below the cloud base is particularly abundant, the raindrops cannot evaporate in the space under the cloud base, but fall directly, and it rains.

During the passage of a warm front, if there is a mixture of cold and warm air, it can cause the front state to be foggy. In the warm zone after the warm front, warm area fog is generated as the warm and moist air flows over the cold ground, and the wind enters the stratus cloud that can form drizzle. If the warm front fog is followed by a warm area with drizzle, or if there is strong precipitation with a cold front after the warm zone fog, this will also lead to the phenomenon of "rain if the fog does not disperse".

Fog generally forms between midnight and early morning, and gradually disappears after early morning. But sometimes the fog builds at night, and it doesn't dissipate during the day, and it rains. Why is that?

Meteorologists say that the fog that does not disperse during the day is generally "frontal fog". Generally speaking, there are thick rain clouds above this fog, and the rain that falls at the bottom of the rain clouds evaporates below the cloud base and condenses near the ground, which is the reason for the formation of the fog before the front.

Since there are thick rain clouds on the top of this fog, the sunlight cannot penetrate in large quantities, and the conditions that produce the fog continue to exist, so of course the fog will not disperse.

Soon, as the rain clouds became thicker and thicker, the water vapor under the clouds became more and more abundant, and the raindrops could not evaporate in the space under the clouds, but fell directly, and it began to rain. Therefore, the old people often say that "if the fog does not disperse, it is rain", there is also a scientific basis.