IITM cloud seeding drive from July

“Last year,IITM had carried out observations from May to October and the data has been uploaded on its website. This year,the institute will undertake actual cloud seeding experiments in certain parts of the country,” Director General of IMD Dr Ajit Tyagi told The Indian Express.

As part of a scientific study on enhancement of rainfall in the country,the Ministry of Earth Sciences has allocated Rs 50 crore for the programme which is a part of Cloud Aerosol Interaction and Precipitation Enhancement Experiment (CAIPEX).

“We have been successful with the first phase of the project and is ready to roll out phase II which should be completed by September,” said Tyagi.

The experiment to create artificial rains through cloud seeding began in 2008. The three-phase process will go on till 2012. The programme is spearheaded by city scientists Dr JR Kulkarni and deputy programme manager Mahesh Kumar. “We will have our base in Solapur and parts of Pune and Marathwada will be covered under the rain shadow regions for the process,” Kumar said.

In the first phase,IITM had studied cloud parameters like temperature,wind,water droplets and aerosol background. The second phase will see both warm cloud seeding through salt and hygroscopic flares and cold seeding using silver iodide. “The seeding will be done from above and below the clouds; after this,the cloud precipitation will be measured in these areas,” said Kumar.

The third phase will measure and analyse the seeding impact next year. Scientists will also to carry out experiments in the monsoon and post-monsoon seasons this year and next year.

If the first phase required Rs 15 crore,the scientists do not want to set the amount for the second phase with the bidding yet to be done.

Indian Institute of Technology-Kanpur,National Aerospace Laboratory-Bangalore,Indian Air Force and Indian Navy will also participate in the project.

How it is done
In the cloud seeding experiment,the seeding aircraft spray hygroscopic particles (salts) that can broaden water droplets in the clouds and hasten the onset of precipitation formation. Automatic rain gauges will be installed in the experimental area to measure the rainfall and samples will be collected from the seeded clouds and non-seeded clouds to compare the impact.