When it snows in winter, is it cold when it snows or after it snows?

When it snows in winter, it is cold after the snow.

The solidification of snow from liquid to solid is exothermic, and because it is cloudy when it snows, the clouds can reflect a lot of long-wave radiation on the ground, even visible light, so they can keep warm, so it is not too cold before the snow, but the temperature has dropped to about zero. ?

After the snow, because the ground is controlled by cold air mass, the weather is fine and there is often snow on the ground. During the day, snow can reflect the heat radiation from the sun. The melting of snow is a process from solid to liquid, that is, it absorbs a lot of heat. ?

At night, because the weather is fine and the temperature is low, there is little water vapor in the air (water vapor can absorb long-wave radiation more), and there is no reflection of clouds in the sky. Long-wave radiation from the ground can pass through the atmosphere unimpeded and be dissipated into outer space, so the temperature will drop sharply. ?

In another case, after snow absorbs the waste heat from the ground, it will reduce the temperature to about zero. At this time, the cold air in the north will continue to push forward, further reducing the temperature. So it's cold after the snow.

Extended data:

Sublimation in life:

1. The process of solid iodine directly changing into iodine vapor by heating is sublimation.

2. It is sublimation that the mother pill gradually becomes smaller.

When ice is heated, it becomes steam directly, which is sublimation.

4. The bulb will turn black when used for a long time, because the filament (tungsten) is heated and sublimated, and the gas condenses when it touches the glass.

5. Heating dry ice into gaseous carbon dioxide is sublimation.

6. The fog seen on the stage is the small water droplets formed by the sublimation and endothermic liquefaction of dry ice when the water vapor in the air is cold, which reduces the surrounding temperature.

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