What is the principle of artificial rainfall?

Scatter catalyst in the plane cloud. Ground combat is to launch from the ground with anti-aircraft guns and rockets. The shell exploded in the cloud, burning the silver iodide in the shell into smoke and scattering it in the cloud. After the rocket reached the height in the cloud, the silver iodide began to ignite, and along with the rocket's flight, there was smoke all the way. Because the aircraft operation requires weather conditions, anti-aircraft gun rainfall and other conditions are generally selected.

According to the physical characteristics of different clouds, choose the right time to spread dry ice, silver iodide, salt powder and other catalysts into the clouds by planes and rockets to promote cloud precipitation or increase precipitation. Artificial precipitation enhancement can be divided into warm cloud precipitation enhancement and Leng Yun precipitation enhancement. In order to make warm clouds (clouds with temperature higher than 0℃) precipitation or increase precipitation, hygroscopic particles such as salt powder and urea should be sown in the clouds to promote the formation of large cloud droplets, which will lead to the formation or increase of precipitation. If precipitation occurs in Leng Yun (cloud with temperature lower than 0℃), it is necessary to spread dry ice, silver iodide and other catalysts by plane to produce a large number of ice crystals, which will increase the density of ice crystals in the upper part of Leng Yun and promote or increase precipitation.

Artificial rainfall is not entirely determined by manpower. Many times, there is "manpower" but lack of suitable time and place, and this precious rain still cannot fall. ?

First of all, there must be clouds in the sky, not ordinary clouds, but clouds that can rain; Then the meteorological department can fire artillery shells or rockets into the sky, hit chemicals into the sky, bombard the clouds to produce powerful shock waves, and make the clouds collide and become raindrops. ?

The generation of general natural precipitation requires not only certain macro weather conditions, but also microphysical conditions in the clouds: first, the clouds should reach a certain thickness; Second, there should be a certain water vapor content in the cloud; Third, there must be an updraft, which condenses water vapor into liquid water through the ascending process.

Artificial precipitation enhancement, also known as artificial rainfall, refers to artificially supplementing some necessary conditions for precipitation according to the principle of precipitation formation in nature, so as to prompt cloud droplets to quickly condense or contact and grow into raindrops and land on the ground. According to the physical characteristics of different clouds, the method is to choose the right time to spread dry ice, silver iodide, salt powder and other catalysts into the clouds by planes and rockets to make the clouds precipitation or increase precipitation, so as to alleviate or alleviate farmland drought, increase irrigation water or reservoir water supply capacity, or increase power generation water.

Precautions:

1 Artificial rainfall operation can only obtain the result of increasing water quantity under certain natural cloud conditions, and the current technical conditions can not achieve artificial rainfall.

The same catalysis may produce different positive and negative results for clouds under different conditions. Therefore, in order to obtain the effect of artificial precipitation enhancement, it is necessary to conduct more in-depth detection and research on natural cloud conditions and precipitation processes.

Natural precipitation has great variability, while artificial precipitation is often relatively small, so it is difficult to distinguish artificial precipitation from natural precipitation in a precipitation process. Therefore, it is still the main goal of weather modification science to evaluate the effect of artificial rainfall and its inspection method. ?

Artificial precipitation enhancement has gradually changed from the initial experimental research to the experimental application technology with rigorous design, diverse detection methods, modern operation technology and communication, and has become one of the measures to combat drought and reduce disasters in China and many countries.

References:

Baidu encyclopedia entry artificial rainfall