(note: Once again Russian scientists admit stopping the toxic Chernobyl cloud in 1986, among other accomplishments. This is an excerpt from a PDF)
NINTH WMO SCIENTIFIC CONFERENCE on WEATHER MODIFICATION
(Antalya, Turkey, 22- 24 October 2007)
SESSION 3.2: FIELD AND LABORATORY STUDIES; OBSERVATIONS (16:00 - 17:30)
CLOUD SEEDING OPERATIONS TO MODIFY WEATHER CONDITIONS OVER CITIES: 2003-2006
Koloskov, B.P., Korneev V.P. , Petrov V.V., Beryulev G.P., Danelyan B.G., Chernikov A.A., Shchukin G.G.
(1) Agency of Atmospheric Technologies (Agency ATTEX, ROSHYDROMET)
Novovagankovsky, Moscow, RUSSIA
(2) Central Aerological Observatory (CAO)
Pervomayskaya , Dolgoprudny, Moscow Region, RUSSIA
(3) Research Center for Atmospheric Remote Sensing,
St. Petersburg, Russia
Some results of activities on cloud seeding operations to modify weather conditions over Moscow and St.Petersburg (Russia) conducted during 2003-2006 are presented. (image right of Moscow, from Google Earth Community)
18 operational works on improvement of weather conditions were executed during this period.
The main purpose of these works was the dissipation of clouds and reduction or stopping of precipitations over the protected cities during the large social, sporting or other special events.
Four basic concepts of cloud dissipation and precipitation redistribution were applied to improve the weather conditions depending on a weather conditions, type of clouds and intensity of precipitation processes:
1) dispersion of stratiform clouds;
2) destruction of convective clouds by a dynamic method;
3) premature rainfall initiation windward of the city with the purpose of the formation of a “rain shadow” (i.e. reduced rain) and
4) intensive seeding of the rain-producing cloud layers with the purpose of “overseeding”.
Up to 12 aircraft, specially equipped with the meteorological equipment, data acquisition systems, “Land – Aircraft – Land” data transmission system and means for cloud seeding have been prepared for fulfillment of the works.
Liquid nitrogen, granulated carbonic acid (“dry” ice), meteorological silver iodide cartridges and packages with coarse-dispersion powder were used as reagents for seeding of clouds.
In weather modification research in Russia, special attention was given to the development of methods and technical means for dissipating clouds of some forms and preventing or substantially reducing precipitation amount.
The practical objectives were to change radiation balance and to increase the income of solar radiation, to reduce municipal expenses for snow removal and clearing the roads and streets in large cities, to create favorable meteorological conditions for carrying out social programs, sporting competitions or some other situations when the necessity may arise to reduce the rainfall.
The first experiment on practical application of these opportunities was carried out during eliminating the consequences of Chernobyl disaster in 1986 /Beriulev et al. 1990/.
Since 1995 the organizations of ROSHYDROMET conducted more than 30 works on improvement of weather conditions in areas of the large cities – Moscow and St.Petersburg. (image left: location of St. Petersburg, from student.britannica.com)
The main purpose of these activities was the dissipation of clouds and reduction or stopping of precipitations over the protected cities.
Analysis of these information showed that due to cloud seeding it was possible:
1) to attain the destruction of stratiform and precipitating convective clouds, or
2) to obtain the considerable, 2-10 times decrease of intensity and amount of precipitation over the protected territories in comparison with rain fallen upwind and in its nearest surroundings, thus demonstrating the effectiveness of cloud seeding operations, conducted in Moscow and St.Petersburg during 2003-2006.