Thiruvananthapuram, Aug. 30
MONSTER hurricane Katrina has had category-matching forerunners in the Bay of Bengal in the not-so-distant past.
A double wall-eyed ogre downgraded to Category-4 on making landfall, Katrina is feared to have ravaged oil and gas platforms as it slammed the US Gulf coast, apart from destroying life and property in the southeast of the country.
Katrina has had worthy predecessors blasting into the Bay of Bengal coast in 1999 and 1990, says Dr Akhilesh Gupta of the National Centre for Medium Range Weather Forecasting. Both the Machilipatnam cyclone of 1990 and the Orissa Super Cyclone of 1999 have been double wall-eyed systems, a rare feature that wrought untold havoc along the southeast coast of India.
The eye wall is the inner most ring of convection near the centre of a hurricane/typhoon, containing the most intense winds and the fiercest rain. While most systems have a single eye wall, many strong and mature hurricanes/typhoons develop the double eye-walled structure (up to 50 per cent of hurricanes in the US). According to Dr Gupta, Katrina has also been noted for the `stadium effect' that her super-defined and destructive `eye' displayed.
Dr Gupta is a member of the Tropical Storms Group, an international network of researchers monitoring tropical cyclonic formations around the globe. He is the only Indian climate scientist from the operational side to be in the network, whose server is hosted at the Colorado University in the US.
The 1990 cyclone crossed the Andhra Coast near Machilipatnam in the late evening of May 9. The 1999 Indian `Super Cyclone' developed in the Bay of Bengal in October that year and became the strongest and deadliest cyclone in the region since the Bangladesh cyclone of April 1991.
The North Indian Ocean is the only area in the world where tropical cyclones are not given names. However, the Joint Typhoon Warning Centre in Hawaii gives identifiers to all tropical cyclones and the Super Cyclone was designated as `05B'.
The previous strongest cyclone in this region was in April 1991. This cyclone struck Bangladesh with estimated winds of 160 mph and a central pressure of only 898 mb. Some 1.38 lakh lives were lost.
But this can hardly hold a candle to the 1970 cyclone, the most devastating ever to hit the region. The target was Bangladesh again. At least three lakh people are believed to have perished in the catastrophe.
Bangladesh has some of the most extensive and thickly populated areas that lie perilously below the sea level and is the favourite playground for deadly weather systems.
The 1999 cyclone ranks as one of the strongest recorded in this region, but as is often the case, it was the heavy rainfall, storm surge and the associated flooding rather than the wind strength that caused most of the devastation and deaths.