El Nino variant may work to India’s disadvantage

Vinson Kurian

Thiruvananthapuram, Oct. 2

The central Pacific El Nino, rather than its better known cousin in the east Pacific, is predicted to become more frequent in the future to the disadvantage of India.

In addition to the eastern Pacific El Nino which we know, a second El Nino in the central Pacific is on the increase, according to Prof Ben Kirtman at the Meteorology and Physical Oceanography Department, University of Miami. Prof Kirtman co-authored a study of the ‘two flavours’ of El Nino, which was published in the September 24 edition of Nature.
WARM CURRENT



El Nino is recurring warm water current along the equator in the Pacific Ocean that affects weather circulation patterns in the tropics. The eastern El Nino increases wind shear in the Atlantic preventing the development of major hurricanes there.

Though the centres of the central and eastern areas are roughly 6,599 km apart, El Ninos historically have not simultaneously occurred in both places, as they do now.

An increase in central Pacific El Nino events may reduce the hurricane-shielding effects of the eastern Pacific event.

Prof Kirtman says that the current El Nino event may end with the winter, perhaps followed by a La Nina, which he expects may bode for a more intense Atlantic hurricane season in 2010.

A La Nina, which is an El Nino in reverse, is considered a good augury for the concurrent Indian monsoon as well.

The central Pacific El Nino has been blamed for worsening drought conditions in Australia and India. Prof Kirtman in turn blames global warming for giving the central Pacific El Nino ‘the edge’ over its eastern cousin.

In an e-mail interaction with Business Line, Prof Kirtman said the current conditions in the tropical Pacific show significant warm anomalies from the coast of South America extending to the west (towards central Pacific).

“Essentially, we are seeing anomalies that are consistent with concurrent central Pacific and eastern Pacific event. I suspect this is part of the reason why the drought in India is so profound and that the Atlantic hurricane season is likely to be weak,” he said.