Scientists plan experiment to find out how cloud-seeding works

Indian weather-scientists are set to undertake a two-year long experiment to find out the best way to cloud-seeding- an artificial way of rain-making.

Scientists have set up the infrastructure like a C-band radar at Solapur in Maharashtra and hired two aircraft for seeding.

The aircraft are expected by May end and the experiment will start in June after the onset of the Southwest monsoon.

Solapur is chosen because it falls in a rain-shadow area. Also, the town is close to Pune where the lead centre, Indian Institute of Tropical Meteorology, is located. The aircraft will operate from the Pune aircraft.

"We aim to find out whether cloud seeding has any prospect; whether the technology is commercially viable and what's the best way to do," M Rajeevan, Secretary, Union Ministry of Earth Sciences told DH.

History

Developed way back in the 1940s, cloud-seeding involved spraying the sky with a cocktail of dry-ice and silver iodide, either from a plane or using a rocket. The chemicals help congregate the dispersed clouds- existing but spread far and wide- and trigger rain.

In Indian States

Though its utility as a rain-making technology is under question for years, cloud-seeding is popular in Indian states battling droughts or severe rain-deficiency.

Tamil Nadu and Karnataka tried it repeatedly in the past while Andhra Pradesh and Maharashtra announced they would do it.

Last year, Maharashtra cabinet approved a plan to seed the clouds for 113 hours, but the plan was not implemented because the normal rainfall was more than enough.

"The benefits of cloud-seeding are poorly understood though lots of organisations make tall claims. That's why we decided to do it," Rajeevan said.

The two aircraft will seed the base of the cloud, which will be tracked by the ground-based radar to find out how many of these clouds are becoming large enough to release raindrops. The experiment will continue for two years to generate the baseline data.

Tried experiment

It's not that India didn't try the cloud-seeding experiments before.

In the 1960s and 1970s, IITM scientists conducted experiments in Uttar Pradesh, Karnataka and Tamil Nadu. But since the 1980s, there is a decline in such studies even though other countries continued with cloud-seeding experiments with more advanced instruments.

The most spectacular use of the technology was demonstrated by China, which used it to trigger premature rains so that the inauguration of the 2008 Olympic remained dry.