Why is there fog in winter What s going on in winter fog

Types of fog:

1. Radiation fog: It mostly occurs at night and early in the morning when it is clear, breezy, and the water vapor near the ground is relatively abundant and stable, or there is a temperature inversion.

2. Advection fog: The fog formed by the horizontal movement of warm and humid air, through the cold ground or water surface, and gradually cooling, is called advection fog in meteorology.

3. Mixed fog: Sometimes the fog formed by both of the above two reasons is called mixed fog.

4. Evaporation fog: that is, cold air flows through the warm water surface, if the air temperature and water temperature are very different, due to the evaporation of a large amount of water vapor from the water surface, the cold air near the water surface will condense into fog. At this time, there is often an inversion layer on the fog layer, otherwise the convection will dissipate the fog.

Therefore, the evaporation fog has a small range and weak intensity, and generally occurs around the pond in the second half of the year.

5. Smog: Smog in cities is caused by another cause, and that is human activity. Morning and evening are the peak period of heating boilers, and a large number of pollutants such as soot suspended solids and automobile exhaust are not easy to diffuse under the conditions of low air pressure and low wind, and combine with the water vapor in the low-level air, which is relatively easy to form smoke (fog), and this smoke (fog) often lasts for a long time.

In general, there is a lot of fog in autumn and winter mornings, why? We know that saturation is reached when the water vapor contained in the air reaches its maximum capacity. 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 is enough to combine with the tiny dust particles in the air, and the water molecules themselves will stick 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 ground heat 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, which is fog. Both it and clouds are caused by a drop in temperature, and fog can actually also be said to be clouds close to the ground.

In this way, the fog neither fell from the sky nor came out of the earth? It is condensation of water vapor in the air. However, it has a close relationship with the temperature and humidity in the sky and on the ground.

Because the temperature is lower in winter, the water vapor and cold air liquefy into small water droplets, forming the fog we see.

It was cold, and the air was condensed.

Fog is formed by the condensation of a portion of water vapor in the air. In the winter season, due to the long nights, and there are more opportunities for cloudless and windless, the ground heat dissipates faster than in summer, and the ground temperature also drops faster, so that the water vapor in the ground air is easy to reach saturation in the second half of the night to the morning and form small water droplets, forming fog. Therefore, there is often fog in winter mornings.

In winter, fog occurs before the northwesterly wind begins to blow. As the saying goes, there are clouds"The fog blows from the westerly winds".

Fog is the condensation of water vapor in the air near the ground.

Causes of fogging at night:

1.During the day, when the weather is clear, there is a light wind, and there is plenty of moisture near the ground, but at night when the temperature drops to a certain value, fogging occurs.

2.At night when the temperature drops to a certain value, when the warm and moist air flow passes.

Fog at night in winter is generally rare, probably because of the cooler temperatures. It is also possible that the air environment in the military area is not good.

If the air near the ground cools to a certain level, the water vapor in the air will condense into fine water droplets suspended in the air, reducing the visibility at the ground level, and the temperature is relatively low in winter due to fog.

Water vapor in the air is formed by the condensation of cold air.

It is mainly foggy caused by the alternation of day and night and the large temperature difference.

In winter, when the air temperature and humidity reach certain conditions, fog will occur. If the air contains more water vapor than the amount of saturated water vapor at a certain temperature in winter, 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 bond to each other, they will become small water droplets or ice crystals, forming fog. <

In winter, when the air temperature and humidity reach certain conditions, fog will occur. If the amount of water vapor contained in the air in winter is more 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 also bond to each other, they will become small water droplets or ice crystals, forming fog.

As follows:

1. When eating popsicles in summer, you can see "white gas" near the popsicles, which is formed by the liquefaction of water vapor in the air when it meets cold.

2. Fog on an autumn morning.

3. In summer, there will be water droplets outside the water pipe.

4. Friends who wear glasses often block their vision by "water vapor" when eating, which is also a liquefaction phenomenon.

5. In winter, water droplets appear on the windows of classrooms.

6. In summer, everyone likes to drink cold drinks of ulnar limbs, and when you hold a bottle of iced mineral water in your hand, there will be water droplets outside.

7. In summer, if the air conditioner is turned on in Qi Tangguo's room, there will be water droplets on the glass outside the window.

8. At night in winter, if you take a shower, there will be water droplets on the window pane.

Mechanism of formation

The process by which a substance changes from a gaseous state to a liquid state. Liquefaction is the reverse process of vaporization, where gas molecules attract each other and condense into a liquid. When liquefied, the substance emits heat. Gases below the critical temperature can be liquefied.

Liquefaction can be achieved by pressurization or cooling, or by pressurizing and cooling. Gases with a critical temperature above or close to room temperature, such as ether, chlorine, ammonia, sulphur dioxide, carbon dioxide, and certain hydrocarbons, can be liquefied by compression at room temperature.