Karnataka's ₹28.5-cr cloud seeding plan runs into weather hurdle

Meteorologists and senior officials on Wednesday cast doubts on the veracity of the government’s plan to kickstart cloud seeding operations around the end of September at a cost of ₹28.52 crore to balance out the state’s rainfall deficit. Experts cited prevailing meteorological conditions to recommend the exercise’s deferment to October, arguing that the atmosphere currently lacks the clouds and moisture needed for the operation.

A senior official from the Karnataka State Natural Disaster Monitoring Centre (KSNDMC), who attended a meeting on the proposed operations on Monday, said the state would first have to identify clouds suitable for seeding. There are currently few such formations, the official said, while forecasts for the next few weeks do not indicate conditions favourable for the exercise.

Cloud seeding can enhance precipitation from an existing cloud but cannot manufacture a rain bearing system in a clear sky. The process also depends on moisture within clouds, supercooled water droplets, wind direction and humidity.

For the operation to have a reasonable chance of producing rain, the IMD has said there must be sufficiently developed cumulus or cumulonimbus clouds, favourable winds and a low pressure area or offshore trough over the sea. Atmospheric moisture between the surface and the clouds must also be at least 55 to 60 mm.

Those requirements are currently not being met.

The state is nevertheless moving ahead with preparations. Deputy chief minister G Parameshwara said the technical team had begun preparations after the government issued orders for the exercise. “We have to see how effective it will be. According to the technical assessment, it may not result in heavy rainfall, but could bring light showers. The experts have said that even such rainfall could help the crops. Based on this, we have agreed to go ahead with the exercise,” he said.

The government’s decision comes against a backdrop of rainfall shortages across Karnataka. KSNDMC has identified 178 taluks in 27 districts as facing drought conditions. The technical assessment was discussed at a meeting attended by representatives of the IMD, KSNDMC, Indian Institute of Science, Indian Institute of Tropical Meteorology, Karnataka Irrigation Corporation Limited, water resources department and rural development and panchayat raj department. Retired experts and meteorologists also took part.

An IMD official said the systems over the Arabian Sea were weaker than those over the Bay of Bengal. A monsoon depression near the Western Ghats has been supporting rainfall over coastal and north Karnataka, while interior and south interior parts of the state continue to receive deficient rainfall.