Precipitation is a basic feature of weather, which means rain.

"Precipitation is a basic feature of weather, which means rain" is wrong.

Precipitation refers to the phenomenon that water vapor in the air condenses and falls to the surface, including two parts. One is that the water vapor in the atmosphere condenses directly on the ground or the surface of ground objects and at low altitude, such as frost, dew, fog and fog, which is also called horizontal precipitation; The other part is water vapor condensate falling from the air to the ground, such as rain, snow, hail, rain, etc., also called vertical precipitation. However, pure frost, pure dew, pure fog and pure fog are not treated as precipitation.

Cause of precipitation formation

1. In the process of rising, due to the gradual decrease of ambient air pressure, volume expansion and temperature reduction, water vapor gradually becomes fine water droplets or ice crystals floating in the air to form clouds. Only when the cloud droplets are large enough to overcome the air resistance and the top support of the ascending airflow, and are not evaporated when falling, can precipitation be formed.

2. Water vapor molecules condense on the surface of cloud droplets, and the constantly moving large and small cloud droplets merge, so that cloud droplets condense (or condense) and increase. Cloud drops grow into raindrops, snowflakes or other precipitation and finally fall to the ground. Artificial rainfall is based on the principle of precipitation formation, which artificially spreads catalysts into the clouds, prompting the cloud droplets to condense, merge and increase rapidly to form precipitation.

Precipitation is the condensation of water vapor obtained from the atmosphere on the ground. It includes two parts: first, the water vapor in the atmosphere condenses directly on the ground or on the surface of objects and at low altitude; The other part is water vapor condensate falling from the air to the ground. The types of precipitation can be divided into frontal rain, convective rain, orographic precipitation and typhoon rain.