WORLD MET DAY 2006
Preventing and Mitigating Natural Disasters
Meteorological Disasters and Weather Modification
By Su Zhengjun (CAMS)
In China, the weather modification activities are organized by local governments, and operated by local meteorological services.
The National Coordination Committee of Weather Modification was established in 1994. In 2004, there were 20 provinces and Dalian City (image at right of Dalian, China, from commons.wikipedia.org) to conduct the operation of precipitation enhancement by using the specialized airplanes equipped with AgI, dry ice or liquid nitrogen generator and PMS probes, with 613 operations of cloud seeding, 1,605 flying hours and the coverage of 3.0 million km2.
Of 2,831 counties of 32 provinces over our country, 1,932 counties of 27 provinces carried out precipitation enhancement and hail suppression operations in 2004 by using the artilleries and rockets on ground. The total area of hail suppression operation was 0.42 million km2 in 2004 across our country.
Currently, there are over 34 specialized airplanes, 6,981 37 artilleries and 2,719 rocket launchers to be used in weather modification operation in China.
Over 35,000 full-time and part-time people involve various operations of weather modification. There were consumes of 870,000 artillery shells, 29,505 rockets, 1,223 AgI-flame, 676-Kg AgI, 11,820-litres liquid carbon dioxide, and 9,760-litres liquid nitrogen in 2004, with the total expenses of 428 million RMB (US$53M).
Though rapid progresses in weather modification have been made in recent years in China, weather modification operations are unlikely to achieve higher scientific credibility until more complete understanding of the physical processes responsible for any modification effect is established and linked by direct observation to the specific seeding methodology employed.
Recent improvements in seeding agents, comprehensive detecting facilities, well-designed commanding system, numerical models, and physical understanding now permit more detailed examination of clouds and precipitation processes than ever before, and significant advances are consequently possible.
Opportunities to increase precipitation are usually few, if any, during droughts. The precipitation enhancement is more effective in cushioning the impact of drought if it is used as part of a water management strategy on a year-round basis.