“We will give outlook for break cycles of monsoon from 2010,” Shailesh Nayak, secretary to the Department of Earth Sciences, said at the 97th session of Indian Science Congress here on Tuesday.
Indian Meteorological Department’s director-general Ajit Tyagi told Deccan Herald from Delhi: “It is an experimental model. But we will issue outlooks, once in seven days, based on this model.” The 2009 monsoon season had three gaps in June, August and September, out of which the most damaging one was the break in June.
After an early onset over Kerala on May 23, monsoon’s further advance was restricted to the west coast and southern peninsula till June 24.
Deficit rainfall
This led to a massive deficit of 54 per cent in all-India rainfall in the first three weeks of June. The overall deficiency in June was about 48 per cent. The shortage was close to lowest ever recorded June rainfall (50 per cent drop in 1926) since 1871. The rest of the season could not make up the deficiency. The all India summer monsoon was 23 per cent deficient in 2009 leading to drought in about 200 districts.
Fervent data analysis over the last six months has helped scientists identify key features responsible for the drought. “One such factor is an anomalous interaction of two different air pressure bands, which can be a pre-cursor to drought,” he said.
“We can monitor the mid-latitude interaction through satellite, the break period can be forecast at least one or two weeks in advance,” Krishnan said. The forecast will come after studying the data with a statistical model.
Since all droughts are associated with long breaks, regular monitoring of break periods will help scientists to advise the government and farmers on the possibility of an impending drought.
