What is artificial rainfall?

Artificial rainfall has become more and more common in our daily life, which has brought great benefits to our lives. In fact, artificial rainfall, to be precise, should be called "artificial precipitation enhancement"

Because according to the current scientific and technological capabilities of mankind, it is still impossible to achieve "rain out of thin air." Only when the cloud is rich in water vapor, changing the rainfall can make the rain with small rainfall bigger, and then change from moderate rain to heavy rain and rainstorm.

Requirements for artificial precipitation enhancement: 1. Water vapor conditions, that is, at a certain height, it is best to have clouds rich in water vapor.

2. Upward movement, because the upward movement will bring water vapor to high altitude and condense into clouds (water vapor will continue to rise, and then encounter heat and then encounter cold, resulting in partial water vapor saturation and precipitation, which is the cloud we see), but only in this way can the conditions for precipitation be achieved.

3. The temperature drops suddenly. In order to make the water vapor in the cloud condense into rain, there must be a sudden drop in temperature. For example, when dry ice sublimes, it instantly takes away a lot of heat, lowers the ambient temperature and makes clouds rain.

4. Condensation nuclei refer to solid, liquid and gas aerosol plasmids that play the role of condensation nuclei in the condensation process, because the condensation of water vapor requires an attachment, and without condensation nuclei, water vapor cannot be effectively condensed.

There are enough ice crystals, and the water droplets in the cloud are very small, which can be stably suspended in the air for a long time. If there are not enough ice crystals, the sky is just a cloudy and rainless state, and silver iodide particles are scattered in the clouds to produce enough ice crystals.

Artificial precipitation and natural rainfall are actually very similar, both of which rely on the condensation of water vapor in the cloud and finally land.

The principle of "artificial precipitation enhancement" is based on the physical characteristics of different clouds, such as the thickness and height of clouds, the amount of water vapor and temperature in clouds. At the right time, we should spread dry ice, silver iodide, salt powder and other catalysts into the cloud by plane and rocket to promote cloud precipitation or increase precipitation, so as to achieve the purpose of precipitation.

Artificial precipitation enhancement can be divided into warm cloud rainfall and Leng Yun rainfall.

Warm cloud rainfall: As the name implies, a warm cloud is a cloud with a temperature higher than 0℃. In order to make it rain or increase rainfall, it is necessary to spread hygroscopic particles such as salt powder and urea in the cloud to get some large water droplets in the warm cloud.

As the initiator of gravity collision (collision and merger process caused by gravity), it destroys the original stability of warm clouds and achieves the existence of large and small water droplets, and then the cloud droplets will collide with each other under the mixed action of atmospheric fluctuation and turbulence, and merge into larger cloud droplets, thus forming precipitation.

Rainfall in Leng Yun: Leng Yun is a cloud with a temperature below 0℃. For cold cloud precipitation, dry ice, silver iodide and other catalysts must be sown by plane, so that a large number of ice crystals (solid hydrate formed by condensation and growth of water vapor on ice cores) are produced in natural clouds, and then the density of ice crystals in the upper part of Leng Yun is increased, thus achieving the purpose of promoting or increasing precipitation.

To sum up, artificial precipitation enhancement can be divided into two forms, but both need to use planes and rockets to launch some catalysts to make the water in the clouds condense together as soon as possible.

The cost of artificial precipitation enhancement The project of artificial precipitation enhancement is complex and requires high equipment and catalysts, so the cost of artificial precipitation enhancement is definitely not low. In order to achieve rainfall, we must first release weather balloons, collect the degree of cloud heat and cold, and establish a rainfall model.

Because precipitation enhancement is divided into Leng Yun and hot clouds, the formation mechanism is naturally different, so the catalysts used are also different. The catalysts for hot cloud rainfall are salt and urea, which are relatively low in cost compared with dry ice and silver iodide needed for artificial precipitation enhancement in Leng Yun.

Secondly, the rockets, planes and launch pads needed for rainfall are all money. For example, a rain bomb, that is, a rocket bomb and an airplane bomb, costs from 2,000 to 4,000 yuan, and the cost of a rocket launcher reaches an astonishing 200,000 yuan.

At first, the cost of artificial precipitation was high, and it was also a waste of resources. But now the technology of artificial precipitation enhancement has become more and more skilled, but even though the technology of artificial precipitation enhancement is improving, artificial precipitation enhancement is still a big expense.

Take the first artificial rainfall in China and Shanghai as an example, the cost reached 4.7 million yuan, of which the cost of catalyst needed for rainfall accounted for nearly 10 of the cost.

Since 1958, the experiment of artificial precipitation enhancement in China has made great achievements. For example, in 20 16 years, the artificial precipitation in China reached 61500 million tons, which made contributions to agricultural production, ecological civilization construction and disaster prevention and reduction.

Under normal circumstances, the time of artificial precipitation enhancement will last for about one hour, and it will cost so much money for one hour. It sounds really painful! Artificial precipitation can effectively solve the drought, so artificial precipitation has both advantages and disadvantages.