Heatwaves may become frequent

Not only the vagaries of monsoon, El Nino is also responsible for the scorching heatwave that sizzles vast swathes of India.

Analysing the heatwave patterns over the last 50 years, Indian weather scientists have spotted a clear link between El Nino – the unusual warming up of the Pacific – and severe heatwave in India. They say, an El Nino year may be followed by an intense heatwave situation in India.

“Most of the years with above normal heatwave activity over India are the years following the El Nino events. For example, 1988, 1995, 1998 and 2010 are the years with above normal heatwave activity when there was no warming of the tropical Pacific (ENSO neutral condition),” they said.

The El Nino-Southern Oscillation (ENSO) neutral condition follows an El Nino year when the unusual warming of the Pacific plays havoc with the weather pattern all over the globe. The study suggests warming of the Indian Ocean too plays an important role in variability of heatwaves over India. “heatwaves over India are not a regional phenomenon. They are linked to planetary scale circulation anomalies and therefore could be predictable,” M Rajeevan, secretary in the Ministry of Earth Sciences and lead author of the study told DH.

Currently, there are no operational forecast for a heatwave from the Indian Meteorological Department, but weather scientists are researching to find out if a heatwave forecast can be made.

With warming of the tropical Indian Ocean and increasing frequency of extreme El Nino events, more frequent and long lasting heatwave events are likely to occur over the Indian sub-continent in near future.

At least two places in western India (Phalodi and Churu in Rajasthan) recorded more than the 50 degrees Celsius temperature this year.