Chongqing finally welcomes artificial rainfall! Experts: This cloud has been "audited"

In recent days,

News of high temperature and drought in Chongqing causing forest fires

The frequent screen swiping makes people quite worried.

To support Chongqing's drought relief efforts,

August 23,

The China Meteorological Administration dispatched high-performance aircraft to Chongqing to help increase rainfall and fight drought.

Experts were also sent to provide guidance on rain-making operations.

Is it possible to carry out artificial rainfall when there are clouds?

How did the catalyst get to the cloud?

Will it have an impact on the environment?

A Science and Technology Daily reporter interviewed experts on this issue.

Let’s learn about issues related to weather modification.

“To achieve rainfall increase,

First, there has to be a suitable cloud."

Zhou Yuquan, chief expert at the Weather Modification Center of the China Meteorological Administration, said:

When the thickness of the cloud exceeds two kilometers,

Lacking ice crystals but rich in water vapor,

Moreover, there is still sufficient water vapor supply outside the cloud.

Even if it passes the "review",

It was identified as having rainfall-enhancing potential.

(Copyrighted image from the gallery, no permission to reprint)

Clouds can be cold or warm.

Warm cloud temperature is above 0℃.

Cold cloud temperature is below 0℃.

“The precipitation mechanisms of cold clouds and warm clouds are different.

The type of catalyst required is also different.”

Zhou Yuquan said,

Currently commonly used catalysts include refrigerants (such as dry ice, etc.),

Crystallization agents (such as silver iodide, etc.),

Desiccant (salt, urea, etc.), etc.

Refrigerants and crystallizers are mainly used for cold clouds.

Warm clouds rely on hygroscopic agents.

How did the catalyst get to the cloud?

Zhou Yuquan pointed out

If it is a layered precipitable cloud system,

The staff will dispatch an aircraft to carry out the mission.

The aircraft that rushed to Chongqing to help was the high-performance "Xinzhou 60" aircraft.

The aircraft has strong maneuverability.

The catalytic operation area is large and the rainfall-increasing effect is good.

Image source: CCTV.com Quick View video screenshot

If you encounter strong convective clouds, there will be a lot of lightning.

Sending a plane is dangerous.

The staff will calculate the location.

Use rocket launchers at the work site

Fires rockets containing catalyst into the air.

“Generally speaking,

When the catalyst is successfully delivered 15 to 20 minutes later,

The effect of the rainfall is immediately apparent.”

Zhou Yuquan said.

Source: Xinhuanet (Photo provided by the Publicity Department of Xianning Municipal Party Committee)

Will catalysts affect the environment?

Experts say,

Catalyst used in shadow work

Mainly dry ice, liquid nitrogen, silver iodide, etc.

It has a high ice-forming ability.

Only a small amount is needed each time.

Taking the commonly used cold cloud catalyst as an example,

Dry ice and liquid nitrogen vaporize into carbon dioxide and nitrogen.

They are the main components of air.

Proper use will not cause environmental pollution.

Source: Science and Technology Daily

◎ Science and Technology Daily reporter Fu Lili

Editor: Wang Chengyue

Review: Yue Liang

Final judge: Wang Tingting