Why is it raining?

Water in the ground, rivers, ponds, oceans and lakes will also become steam and rise to the sky after being irradiated by sunlight. Because the sky is very cold, water vapor will become the original water droplets when it meets cold air. The more tiny water droplets accumulate, the more they become clouds. The clouds are getting bigger and bigger, and because they are too heavy, they slowly fall. We know that the higher the place, the colder the air, so the water droplets gathered there will become ice particles. It is very cold in winter, and the ice particles turned by these water drops will turn into snow and fall to the ground. When it snows, if you encounter warm air halfway, the snow will melt and turn into rain. However, clouds near the ground will also turn into rain.

2, the basic process of rain formation is

The water vapor in the air condenses into small water droplets or small ice crystals at high altitude, which collide with each other and get bigger and bigger. When the air can't hold it, it will fall down. When the low-altitude temperature is higher than 0℃, it is rain.

3. Water becomes a cloud.

Clouds composed of liquid water droplets (including supercooled water droplets) are called water clouds. If the conditions for cloud droplets to grow into raindrops are met in the water cloud, and the raindrops have a certain falling speed, then it is rain or Mao Mao rain that falls. Clouds composed of ice crystals are called ice cloud, and clouds composed of water droplets (mainly supercooled water droplets) and ice crystals are called mixed clouds. Ice crystals or snowflakes falling from ice cloud or mixed clouds fall into the gas layer above 0℃, and after melting, they also fall to the ground as raindrops, forming rainfall.

4, the role of big water droplets

In the process of rain formation, large water droplets play an important role. When the radius of water droplets increases to 2-3 mm, it is difficult to maintain such a large water droplet by the attraction between water molecules, and it is easy to be split by the impact of airflow on the way down, through a "chain reaction." Make big water droplets fall, and small water droplets continue to exist, forming new big water droplets. This is an important reason for the formation of rain in water clouds and mixed clouds with strong updraft.