The picture shows the high-performance rain enhancement aircraft of China Meteorological Bureau.
Photo courtesy of Weather Modification Center of China Meteorological Bureau
Weather modification Using scientific and technological means to intervene in the weather can increase rain and snow, prevent hail disasters, and benefit mankind. Following the Yun Geng Action Plan on Weather Modification (2020— In 2022), recently, the China Meteorological Bureau issued the "Weather Modification" Rain Mitigation Action Plan (2023— 2025) (hereinafter referred to as the "Rain-sowing Plan"), defining the high-quality development goals and key tasks of weather modification in the next three years, and proposing that by 2025, a standardized, efficient, technologically advanced, safe and reliable, multi-field, multi-category and all-round new working system of weather modification will be basically formed.
How does weather modification "turn clouds into rain"? How will the plan of "sowing rain" seek advantages and avoid disadvantages, and protect beautiful homeland? The reporter conducted an interview.
Weather modification is not just about increasing rainfall.
On February 7-8, snowfall occurred in the eastern agricultural area of Qinghai Province and the southern foot of Qilian Mountain. Qinghai meteorological department seized the opportunity to organize and implement artificial precipitation (snow) enhancement by aircraft and ground in Huangshui Valley, Yellow River Valley and the southern foot of Qilian Mountain. According to statistics, from 20: 00 on the 7th to 20: 00 on the 8th, the weather modification operation increased the local accumulated precipitation by 0.1 to 5.6 mm, which effectively alleviated the drought in the eastern agricultural area and the southern foot of Qilian Mountain, and was conducive to reducing the fire risk level of forest and grassland, improving ecology and spring ploughing production.
At present, it is in the period of spring ploughing production, and weather modification operations are carried out in many places to alleviate drought, improve soil moisture and meet the needs of crop sowing and growth.
Is weather modification artificial rain and snowfall? Of course it’s not that simple. Li Jiming, deputy director of the Weather Modification Center of China Meteorological Bureau, told the reporter that weather modification refers to the artificial influence on the physical process of local atmosphere by scientific means, so that the weather phenomenon can be transformed in the predetermined direction. Weather modification can increase rainfall, but it can’t make rain or rain out of thin air. "It is necessary to find clouds with precipitation potential, water vapor transport and updraft areas, and then carry out catalyst seeding operations on qualified clouds at the right time to achieve the purpose of precipitation enhancement."
In fact, weather modification is not only about increasing rainfall and snowfall, but also about hail suppression, fog elimination and frost prevention. At present, many weather modification operations in China are artificial precipitation (snow) and hail suppression.
After more than 60 years of development, especially since the 18th National Congress of the Communist Party of China, the cause of weather modification in China has developed rapidly, forming a national — Province — City — The county-level four-level weather modification business system has made important contributions in disaster prevention, mitigation and relief, ecological environment protection and restoration, national major activities support, and major emergencies emergency support.
Last year, high temperature and drought continued in most parts of southern China. From June to mid-November, many places in southern China organized 241 sorties of aircraft precipitation enhancement operations and 15,000 ground precipitation enhancement operations, which increased precipitation by about 8.56 billion tons, effectively alleviating the drought and playing a positive role in increasing storage and capacity of reservoirs and ensuring energy supply. Last year, the national weather modification increased precipitation by about 39.8 billion tons, and the hail suppression operation protected an area of about 650,000 square kilometers, reducing economic losses by about 14.1 billion yuan.
Equipment and technology are at the advanced level in the world.
The high-quality development of weather modification can not be separated from the strong support of scientific and technological means.
According to Li Jiming, weather modification requires scientific and technological means to monitor the weather conditions formed by clouds and precipitation. For example, the thickness of clouds is more than 2,000 meters, the water vapor is sufficient, and the supercooled water content in clouds exceeds 0.01g/kg. Only when certain conditions are met can operations be considered. Then, the catalyst is accurately delivered to the appropriate part of the cloud by means of aircraft, rockets, anti-aircraft guns, ground smoke stoves and so on. Different operation methods are adopted according to different requirements.
Which cloud can melt rain? Meteorological departments rely on modern detection equipment, including ground-based cloud precipitation special observation equipment such as weather radar, cloud radar and microwave radiometer, space-based observation systems such as radiosondes and airplanes, and space-based observation systems such as geostationary satellites and polar-orbiting satellites. Using the observation data obtained by these devices, the Center for Weather Modification has developed a cloud precipitation monitoring and forecasting system, which is used to judge whether it is suitable to carry out weather modification operations.
After the monitoring, the operation scheme design and command were carried out, and the weather modification center developed refined cloud structure products, working condition monitoring and identification methods, etc., to accurately "lock" which cloud is suitable for melting rain. In order to evaluate the operation effect, a simulation evaluation system for the catalytic effect of weather modification and various scene evaluation products have been developed. At the same time, a number of advanced experimental facilities, such as warm cloud expansion cloud chamber, cloud physics and catalytic technology research and development experimental platform, have been put into use one after another, which has effectively improved the ability of weather modification.
With the strong support of governments at all levels and relevant departments, the modernization level of weather modification equipment in China has made great progress. High-performance aircraft equipped with monitoring, catalysis, communication, integration and other task equipment and systems, carrying suitable catalysts, can carry out the operation of turning clouds into rain at any time according to cloud types, greatly improving the ability and level of precise operation. At present, there are six national-level high-performance aircraft for weather modification in China. In the rain enhancement and drought relief in Henan, Hubei, Chongqing and Sichuan last year, large unmanned aerial vehicles complemented manned aircraft operations, which improved the ability of weather modification in all time and all terrain.
"At present, China’s weather modification operations are the most complete and diverse, and the equipment and technical level are generally at the advanced level in the world." Li Jiming said.
We will focus on building seven experimental demonstration bases.
According to Wang Yawei, Deputy Director of Emergency Disaster Reduction and Public Service Department of China Meteorological Bureau, the plan of "sowing rain" will focus on promoting the high-quality development of weather modification, focusing on scientific operation, precision operation and safety operation, accelerating the development of weather modification from scattered, extensive and relatively independent to intensive, research-oriented, safe and integrated, and improving the modernization level of weather modification with wisdom as the main feature.
More scientific — — In terms of business layout, the "Rain-sowing" plan will improve the four-level business layout, broaden the original five-segment real-time business into seven-segment real-time business, and increase the prospect of preliminary operation conditions and the safety management of the whole business process.
Focus on the national strategy, focus on the main grain producing areas, key ecological areas of "three areas and four belts", major activities and major emergency needs, improve the layout of operational aircraft, and optimize the planning and layout of weather modification test demonstration bases. Form an air operation force with high and low altitude, wide coverage and strong maneuverability, and enhance the ability to support weather modification under various conditions. We will focus on building seven experimental demonstration bases in southwest, north China and southeast China, and encourage all localities to build experimental demonstration bases for weather modification according to local needs and carry out research and experiments.
More accurate — — According to the time nodes of one week, 72 hours, 48 hours and 3 hours, the operation process forecast, operation potential forecast, operation condition forecast and operation condition monitoring and early warning are carried out respectively. Establish the effect evaluation and benefit evaluation business of weather modification operation for normalization, typical process and annual service scenarios.
Safer — — Improve the technical standards and specifications for weather modification safety supervision, speed up the installation of new operational equipment such as high-performance rain enhancement aircraft, promote the automation, standardization and information transformation of ground operational equipment, realize real-time dynamic safety supervision of weather modification equipment and ammunition, and improve the level of safe operation.