Opinion - Editorials

Whither the monsoon?

Come the monsoon, worries about how the season will turn out begin to preoccupy people from all walks of life. This year, the rains set in over Kerala on May 31 and progressed swiftly northwards. As a result, the monsoon reached Delhi two weeks earlier than normal. By June 29, the country as a whole had received 21 per cent more rain than usual. Will the monsoon be as generous in the coming months? In its updated forecast issued on June 30, the India Meteorological Department (IMD) has reiterated its prediction made in April that this monsoon is likely to be a “near-normal” one, with countrywide rainfall close to the long-term average. The forecast as well as the update are based on a statistical model developed by the IMD’s scientists. Last year, an unusual cooling of the surface waters of the central Pacific Ocean, known as La Nina, was beneficial for the monsoon, which ended with slightly-above-average nationwide rains. The La Nina, which persisted into this year, has now largely dissipated. Were the surface waters of the equatorial central Pacific to warm in the coming months and produce El Nino, that could potentially have an adverse impact on the monsoon. In an assessment issued recently, the World Meteorological Organisation took the view that near-neutral conditions in the Pacific were the most likely outcome in the next few months. However, it warned of uncertainties in such prediction and said “there is need for careful monitoring over the coming weeks.”

In its updated forecast, the IMD has drawn attention to the prediction from some climate models of a “positive Indian Ocean Dipole (IOD)” occurring this year too. A positive IOD, characterised by a cooling of the eastern Indian Ocean near Indonesia and a warming of the western Indian Ocean off Africa, favours good rains over India, especially in September. However, a cooling of the eastern Indian Ocean can also help an incipient El Nino grow faster. Even if the monsoon turns out to be near-normal, there is the issue of how much rain different regions of the country will receive. Research by scientists at IMD’s National Climate Centre in Pune has revealed significant changes in the distribution of rainfall over the past century during the monsoon. Kerala, Chhattisgarh, Jharkhand now receive less rain than they used to, while much of West Bengal as well as parts of Uttar Pradesh, Maharashtra, Andhra Pradesh, Karnataka, Goa, and Jammu & Kashmir are getting more of it. Policy-makers would do well to pay heed to such long-term trends and initiate measures to better cope with the vagaries of the monsoon.

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