The Hindu Business Line : `Aborted' El Nino this year: Experts

CLIMATE experts on this side of the Pacific are not unduly perturbed by an Australian researcher's predictions about heightened possibility of an El Nino event returning towards the middle of this year.

Speaking to Business Line, Dr P.V. Joseph, renowned meteorologist and former director of India Meteorological Department (IMD), said a `warming anomaly' in the Central Equatorial Pacific has been persisting for the past several months. But this is unlikely to result in an El Nino.

Dr Joseph quoted from the latest observations made by the National Oceanic and Atmospheric Administration (NOAA) of the US that this anomaly is likely to die down by September/October when El Nino conditions are known to peak.

This has been the consensus opinion of a majority of the climate scientists watching the El Nino phenomenon. According to them, the emerging scenario would most probably lead to an `aborted El Nino' by the end of this year.

What seems to have set off alarm bells is the unexpected warming of the Pacific Ocean in February this year reducing the mean sea level pressure between Tahiti and Australia (expressed in the Southern Oscillation Index, or SOI, value) to a 22-year low.

Negative values of this index indicate El Nino conditions, and positive, La Nina, the exactly reverse phenomenon.

Rising Pacific Ocean temperatures shift the warm waters east, moving clouds and moisture to the Americas and reducing rainfall in Asia and Australia. A similar scenario eight years ago had developed into an intense El Nino that caused droughts in Asia, floods in South America and tornadoes in the US.

The Tahiti-Darwin pressure differential may have nosedived (from 2 to minus 29) in February but the same has since returned to quite normal as of March, says Dr M. Rajeevan, Director - Forecasting, IMD, Pune. The abnormal value for February 2005 could be blamed on excess tropical cyclone activity over the Central Pacific (near Tahiti).

According to the Climate Prediction Centre at the International Research Institute of Columbia University, sea surface temperatures in the East-Central Equatorial Pacific have returned to near normal by late March, although they remain above average throughout much of the Equatorial Pacific. Based on the latest observations and forecasts, it is 65 per cent likely that neutral conditions will prevail over the March-April-May 2005 season.

Article E-Mail :: Comment :: Syndication :: Printer Friendly Page