CLOUD SEEDING

WHY IN NEWS?

PIB: IITM, Pune released report on cloud seeding

BACKGROUND

• Clouds are made up of tiny water droplets or ice crystals that form when water vapor in the atmosphere cools and condenses around a tiny particle of dust or salt floating in the atmosphere.
• Without these particles, known as condensation or ice nuclei, raindrops or snowflakes cannot form and precipitation will not occur. 

ABOUT

• Cloud seedingis a type of weather modification that aims to change the amount or type of precipitation that falls from clouds by dispersing substances into the air that serve as cloud condensation or ice nuclei.
• These nuclei provide a base for ice crystals/water droplets to form.
• After cloud seeding takes place, the newly formed ice crystals/water droplets quickly grow and fall from the clouds back to the surface of the Earth, increasing precipitation

 TECHNIQUE

The most common chemicals used for cloud seeding include silver iodide, potassium iodide and dry ice (solid carbon dioxide)

Cloud seeding chemicals may be dispersed by aircraft or by dispersion devices located on the ground (generators or canisters fired from anti-aircraft guns or rockets).

BENEFITS

• Agriculture:

It creates rain, providing relief to drought-stricken areas.

E.g.: ‘Project Varshadhari’ in Karnataka in 2017.

• Power Generation:

Cloud seeding experiments have shown to augment production of hydroelectricity during the last 40 years in Tasmania, Australia.

• Water Pollution Control:

Cloud seeding can help to maintain minimum summer flows of the rivers and dilute the impact of treated wastewater discharges from municipalities and industries.

• Fog Dispersal, Hail Suppression, and Cyclone Modification:

“Project Sky Water” of the U.S.A. in 1962 for weather modification through cloud seeding aimed at fog dispersal, hail suppression, and cyclone modification.

• Tackle Air Pollution:

Cloud seeding can potentially be used to settle down toxic air pollutants through the rain.

E.g.: Recently, the Central Pollution Control Board along with other researchers mulled the use of cloud seeding to tackle Delhi’s air pollution.