Dr. Mohapatra said the number of light or moderate rainfall on an average was decreasing, while events of extreme rainfall were increasing.
Extreme events will intensify and become more frequent if current projections are taken into account, said India Meteorological Department Director-General Dr. Mrutyunjay Mohapatra. Speaking to The Indian Express, He attributed the rise in global temperatures for the increased frequency of such events.
Dr. Mohapatra said global temperatures had risen about 1.2 degrees Celsius from 100 years ago. The corresponding rise in India has been about 0.6 degrees Celsius, with the peninsular part experiencing a lower change compared to the country’s eastern, central, and northern parts.
The Met department chief said during his interview with The Indian Express that the troposphere was also heating up, alongside the surface temperature, leading to higher capacity for water holding. According to studies, a 1-degree Celsius rise in temperature corresponds to A 7-per cent higher moisture-holding capacity. Dr. Mohaptara said rainfall will go up if the atmosphere’s water-holding capacity goes up.
According to the weather bureau chief, the probability of heavy rainfall has gone up. Studies also pointed to an increased frequency of heavy rainfall events — the cumulative rainfall over a 24-hour period being higher than 15 cm. Such events are on the rise in global tropical belts, including India where the trend is evident in Gujarat, Maharashtra, West Bengal, and Odisha.
Dr. Mohapatra said the number of light or moderate rainfall on an average was decreasing, while events of extreme rainfall were increasing. However, total monsoon rainfall has remained largely unchanged, meaning that it rains heavily when it rains or not at all when it doesn’t.
He pointed to the country’s central belt where the trend is more pronounced. The IMD has observed declining rainfall over Jharkhand and Kerala and adjoining areas. However, rainfall activity has seen a rise in western Uttar Pradesh, West Bengal, and parts of Karnataka.
While heat waves have gone up in central and northern India, coldwave conditions are likely to decline due to higher temperatures. Lightning strikes have also seen an increase, Dr. Mohapatra said, as have thunderstorms due to higher atmospheric moisture content.
The weather expert added the intensity of Bay of Bengal cyclones has not seen any significant change, but Arabian Sea cyclones have displayed increasing intensity.