Did rains fail?

Or the forecasting system?

 
By T V Jayan
Last Updated: Saturday 04 July 2015

The departure from the predicted quantity of rain in meteorological subdivisions in these states ranged from the manageable 17 per cent to the whopping 51 per cent (see map: Fickle rains, awry predictions). Unlike earlier years, the subdued monsoon activity in India did not translate into bountiful rains in other countries in the region. "This year it seems the lull's every where," the imd scientist said.

As statistical regression models, which are used for forecasting monsoon since 1988, have failed repeatedly, a probable solution would be using dynamic global circulation models. Unlike the former, which use historical data for prediction, the latter use real-time ocean, wind and land data. It is here that the Indian Ocean becomes crucial, acting as a black box for making the prediction, says M Rajeevan, director for long range forecasting at imd. But J Srinivasan, professor at the Bangalore-based Indian Institute of Science, avers: "No model can predict monsoon fluctuations. I am not sure whether models that claim to have such capacity can predict for small regions like Rajasthan."

Scientists suggest launching a major mission-mode programme to study the Indian Ocean, similar to the 15-year-long Tropical Ocean Global Atmosphere (toga) climate project spearheaded by us National Oceanic and Atmospheric Administration to unravel El Nio (warming in the tropical Pacific Ocean) and La Nia (cooling) in the 1980s. Apart from providing benefits to American agriculture, the findings of this project lent tremendous accuracy to the forecasting of monsoon in many countries, including Brazil and many African nations, Rajeevan points out.

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