Cloud Seeding : In News
In the wake of disastrous floods in Texas, concerns about cloud seeding technology have run rampant.
- Cloud Seeding is the deliberate introduction into clouds of various substances that act as condensation nuclei or ice nuclei in an attempt to induce precipitation.
- The first experiments with cloud seeding were conducted in 1946 by American chemist and meteorologist Vincent J. Schaefer, and since then seeding has been performed from aircraft, rockets, cannons, and ground generators.
- Many substances have been used, but solid carbon dioxide (dry ice) and silver iodide have been the most effective.
- When used in supercooled clouds (composed of water droplets at temperatures below freezing), they form nuclei around which the water droplets evaporate.
- The resulting water vapour deposits into ice crystals, which build quickly as water droplets attach themselves.
- In clouds at temperatures above freezing, calcium chloride particles provide the condensation nuclei around which raindrops form.
