Entire country

got above-normal

rainfall

Outstanding dissimilarities in rainfall in Kerala

KOCHI: Global warming may be an esoteric subject for the huge majority of Keralites, but its impact is here for everyone to experience.

The one-fourth excess rainfall during the southwest monsoon, accompanied by flooding and other devastations, is one of the direct impacts of the climate changes unleashed by global warming, according to atmospheric scientist and director of Cochin University’s Centre for Monsoon Studies C.K. Rajan.

The fabled southwest monsoon, reckoned as a great nature’s blessing for Kerala, has been particularly harsh this year with continuous rain for weeks together. Though September is a weak monsoon month, rainfall has been heavy and continuous in the past three weeks, and according to indications, it will be here for a few more days. “This is worrisome,” said Dr. Rajan. “It indicates drastic changes in monsoon’s characteristics.”

Generally, the monsoon runs its course during June-September, with rainfall petering off in September. Until recently, monsoon used to set in over Kerala on June 1, plus or minus three days. But, this year, it arrived in the second half of May, and after a few showers, shied away for two weeks. Last year too, the rain came shortly after mid-May and then it did not rain until well into June. The changes have been quite apparent in the past three to four years, Dr. Rajan said. “It seems the basic characteristics of monsoon have changed; the textbooks on monsoon now need to be rewritten.”

So far, there was nearly one-fourth increase in the total rainfall during this season. “Who knows, next year there would be a shortfall in the rainfall,” he said.

He said that monsoon pattern has changed across the country. This year, almost the entire country received above-normal rainfall. Southern India, Gujarat and Maharashtra had excess rainfall of around 20 per cent, though the Konkan belt had only normal fall.

The Rayalaseema region in Andhra Pradesh received 103 per cent extra rain (until the week ending September 12). The perpetually rain-starved areas of Rajasthan had reeled under floods, but at the same time, the ever-raining areas of Assam and Andaman & Nicobar got only less than normal rainfall. This clearly indicated a change in the pattern and characteristics of the monsoon. But more than the volume of rainfall, it is the diversity that should attract the attention of scientists as well as policymakers, Dr. Rajan said.

In Kerala, until recently, the rainfall used to be near-uniform across the State, but this season there has been outstanding dissimilarities among districts. For instance, while the State received nearly 25 per cent extra rainfall, Palakkad got 45 per cent extra, while Thrissur got 40 per cent more.

Global warming was causing violent changes in climate, he said.

Rise in the temperature affected the moisture content in the air which directly influenced monsoon and hence rainfall.Dr. Rajan said there were several earthquakes in the seas in the tropical regions in the past few months. Such natural phenomena, though they take place thousands of miles far off, make an impact on our monsoon, he said.

He wanted scientists, politicians and policymakers to be prepared for the changes in the pattern and characteristics of the monsoon. “They should be ready to make use of the positive upshots and take precautionary measures against the negative ones,” he said.