Snowflakes are goose feathers shaken by the little angel pulling the pillow and scattered all over the floor. Snowflakes are cotton wool that Mother Sky rents to the earth to make warm quilts.
Ice and snow are introduced as follows:
Ice and snow, Chinese vocabulary. Pinyin: bóng Xuě, which means ice and snow; Metaphor is the loyalty of the soul and the nobility of character.
Snowflakes are introduced as follows:
Snowflake, a kind of crystal, whose structure changes with the change of temperature, also known as Weiyanghua and Liuchu, is a beautiful crystal, which forms a snowflake in the process of falling.
The origin of snowflakes is introduced as follows:
One condition is that water vapor is saturated. The maximum amount of water vapor that air can hold at a certain temperature is called saturated water vapor. The temperature at which air reaches saturation is called dew point.
When saturated air is cooled to a temperature below the dew point, the excess water vapor in the air becomes water droplets or ice crystals. Because the saturated water vapor content of ice surface is lower than that of water surface, the water vapor saturation required for the growth of ice crystals is lower than that of water droplets.
That is to say, water droplets can grow only when the ratio of the actual vapor pressure in air to the saturated vapor pressure of air at the same temperature is not less than 100%.
As for ice crystals, they tend to grow when the relative humidity is less than 100%. For example, when the temperature is -20℃ and the relative humidity is only 80%, ice crystals can grow. The lower the temperature, the less humidity is needed for the growth of ice crystals. Therefore, in the high-altitude and low-temperature environment, ice crystals are more likely to be produced than water droplets.
Another condition is that there must be condensation nuclei in the air. Some people have done experiments, if there is no condensation nucleus, the water vapor in the air will only condense into water droplets if it is supersaturated to a relative humidity of more than 500%. But such a large supersaturation phenomenon will not exist in the natural atmosphere. So without condensation nuclei, it is difficult for us to see rain and snow on the earth.
Condensation nuclei are tiny solid particles suspended in the air. The ideal condensation nucleus is the particle that absorbs the most water, such as sea salt, sulfuric acid, nitrogen and other chemicals. So we sometimes see clouds in the sky, but there is no snow. In this case, people often use artificial snowfall.