An example of canal formation in a thick cloud induced by massive seeding using liquid carbon dioxide
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The purpose of this experiment is to show that massive cloud seeding is effective in mitigating the damage caused by heavy snowfall. In order to show its effect, we attempted to form a canal in a thick convective cloud by massive seeding, and left the parts that were not influenced by the seeding as a reference to show that the canal was formed by the massive seeding only. The seeding was carried out by using an aircraft. The seeding rate and air speed of the aircraft were 35 g s−1 and 115 m s−1, respectively. The flight course for seeding was selected to be parallel to the wind direction to ensure that the dispersed liquid carbon dioxide did not influence both sides of the course. The results show that a part of the radar echo observed from onboard beneath the seeding track was weakened and divided the radar echo into two parts 20 minutes after the cloud top and the bottom were seeded, and distribution of rainfall rate on the ground from the target cloud was confirmed to be divided into two parts 24 minutes after the seeding. The target cloud was torn along the seeding track, and we could see the sea surface through the break in the cloud. Canal formation occurred in the cloud along the seeding track. Clouds and snowfall were left on both sides of the canal. The results show that supercooled liquid cloud particles along the seeding track evaporated to form larger precipitable particles which grew and fell rapidly.
Keywordsheavy snowfall weather modification aircraft artificial cloud seeding
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- Coons, R. D., E. L. Jones, and R. Gunn, 1948: Second partial report on the artificial production of precipitation: Cumuliform clouds, Ohio, 1948. Bull. Amer. Meteor. Soc., 29, 544–546.Google Scholar
- Dai Jin, Yu Xin, Rosenfeld D., et al., 2007: Microphysical effects of cloud seeding in supercooled stratiform clouds observed from NOAA satellite. Acta Meteor. Sinica, 21, 224–233.Google Scholar
- Garstang, M., R. Bruintjes, R. Serafin, et al., 2004: Weather modification: Finding common ground. Bull. Amer. Meteor. Soc., 85, 647–655.Google Scholar
- Ikawa, M., H. Mizuno, T. Matsuo, et al., 1991: Numerical modeling of the convective snow cloud over the sea of Japan. Precipitation mechanism and sensitivity to ice crystal nucleation rates. J. Meteor. Soc. Japan, 69, 641–667.Google Scholar
- Miyagi, H., T. Iriguchi, D. Satoh, et al., 2012: Improvement of analysis rainfall, precipitation short time forecast, and precipitation nowcasting. Training text of forecast technology in Japan Meteorological Agency, 18, 108–121. (in Japanese)Google Scholar
- Sakakibara, H., M. Ishihara, and Z. Yanagisawa, 1988: Squall line like convective snowbands over the Sea of Japan. J. Meteor. Soc. Japan, 66, 937–953.Google Scholar
- Stewart, R. W., 1986: Weather modification in Alberta. Summary report and recommendations.Google Scholar
- Stull, R. B., 1997: An Introduction to Boundary Layer Meteorology. Springer, Netherlands. 17 pp.Google Scholar
- Zoljoodi, M., and A. Didevarasl, 2013: Evaluation of cloud seeding project in Yazd Province of Iran using historical regression method (case study: Yazd 1 cloud seeding project, 1999). Nat. Sci., 5, 1006–1011.Google Scholar