India today declared that it has the technology to ensure artificial rain, using cloud seeding method, but will “use it only in extreme circumstances” as such an experiment could have adverse impact on climate for other parts. But, the government has made it clear that in the next five years, the focus will be on weather modifications.

Unveiling the logo to commemorate 150 years of India Meteorological Department (IMD) in New Delhi, on Tuesday, the Union Earth Sciences Minister, Kiren Rijiju, said: “There is a system/technology available. How to use it, where to use it that we have to take a decision. Suppose there is drought somewhere, there you can think of making it available. Even where flooding is there, you can suppress the rainfall.”

The minister, further, said since it is a highly technical subject, it is also a big question on how to use the technology. “When I use the word weather management, it is playing with nature. But if it is critical for the survival of humanity, can be used. The weather system is so sensitive, if you want to tweak the flow of monsoon here, it may cause desertification somewhere else. We have to really think in terms of morality.”

Focus on modification

Reflecting on the cloud seeding technology, Earth Sciences Secretary M Ravichandran said there is a need to have a policy, as making it rain artificially means someone gains and somebody loses in terms of pace and time. “Whether we need to do (artificial rain), how much we have to do, where to do, these things we have to work out,” Ravichandran said. Over the next five years, the focus will be on weather modification, he said.

A cloud-seeding experiment carried out by the Pune-based Indian Institute of Tropical Meteorology (IITM) in Solapur, Maharashtra, yielded 384 mm rainfall in 2018 and 422 mm in 2019 during monsoon season (June-September), which was 18 per cent relative enhancement in rainfall. The relative enhancement of accumulated rainfall was seen over two hours after seeding the clouds.

The primary objective was to investigate the efficacy of hygroscopic seeding in deep convective clouds and to develop a cloud seeding protocol. The experiment used two aircraft for studying various cloud parameters and for seeding the clouds. The study found that cloud seeding is an effective strategy for enhancing rainfall in a region under suitable conditions.

Monsoon mission

Speaking on the event, IMD’s Director-General, M Mohapatra, said because of the monsoon mission — which was launched in 2012 with an objective of coming up with accurate forecasts for short, medium, and long ranges — India is able to issue more accurate monthly forecast for different geographical regions during the season.

“Earlier, there was only one forecast of the value of rainfall for the whole season. From that we are now (since 2021) releasing monthly forecast as well as for every State and even for different regions within a State. All these developments are possible due to monsoon mission. Newer products will certainly come up as IMD has moved from statistical model to dynamical model,” Mohapatra said.

Rijiju also said there was a need to set up more observatories to make better weather forecasts, including the extreme rainfall events, like the ones witnessed in Tamil Nadu. He said Tamil Nadu normally receives heavy rainfall in December, but there were no measures to prevent such heavy downpour. “We only have to remain alert and take steps to prevent loss of lives,” the Minister said.

No prediction of TN deluge

Ravichandran said none of the weather prediction models had anticipated 90 cm rainfall which was witnessed in Kayalpatnam municipality in Thoothukudi district of Tamil Nadu on December 17 and 18. The districts of Tirunelveli and Kanyakumari and Tenakasi also experienced heavy rainfall.

He said efforts were on to further improve weather forecasting by installing a new high power computing system and incorporating more observations from different weather stations.

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