Monsoon

This is the link to my story in The Hindu on January 7, 2009:
http://www.hindu.com/2010/01/07/stories/2010010754200400.htm
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‘Global warming can alter monsoon pattern’

P. Venugopal

THIRUVANANTHAPURAM: What could be the impact of global warming on the behaviour of the Indian summer monsoon, which is the lifeline of the subcontinent?

Scientists in the country are on the job of creating a model that can simulate the likely changes in the flow and sweep of the monsoon as the earth warms up, by small decimals of a centigrade each year, under the influence of global warming.

“We are working on a model… It is the key,” said R. Krishnan, head of the Climate and Global Modelling Division at the Indian Institute of Tropical Meteorology (IITM) in Pune, while addressing a plenary session on ‘Weather, Climate and Environment’ at the 97th Indian Science Congress in Thiruvananthapuram on Tuesday.

He spoke of the dynamics of the Indian monsoon, how it flowed in from the southwest at the beginning of June every year with the building up of an atmospheric pressure gradient down to the north, how the temperature factors even in central Pacific and interior Asia had a bearing on its behaviour and how it was all a phenomenon of interrelated global factors.

The hitherto perceived pattern of the monsoon can change as the temperatures over the land and the ocean rise under the global warming phenomenon. The wind speeds and wind directions can change and so also the known and unknown factors that govern the intensity and spread of the monsoon over the subcontinent.

The IITM turned the drought of 2009 into an opportunity to study the wind behaviour that had delayed the monsoon over the central, north and northwest India this time, besides causing long lulls in rainfall activity during the four-month season from June to September. One of the findings was that an aberrant westerly current from the cold and dry central Asia had kept pushing the monsoon currents back from these regions for long periods within the season.

The drought of 2009 was the third biggest drought the country had encountered in the last 100 years, Dr. Krishnan said. There were three long break-spells for the monsoon this time, resulting in 23 per cent deficient rainfall for the country. Dr. Krishnan said it was not India alone that was monsoon deficient this time, but the whole of Southeast Asia.

Speaking in the same session, Shailesh Naik, Secretary to the Ministry of Earth Sciences, said the hottest years of the last 100 years for the country had come during the last one decade. He said his department had stepped up support for research into a whole range of climate-related topics.

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