A. Operational Definition
A cyclone is an intense vortex or whirl of air in the atmosphere characterized by very strong, rotating winds moving in an anti-clockwise direction in the Northern Hemisphere and in a clockwise direction in the Southern Hemisphere. A cyclonic storm has wind speeds of 62 kmph and above. The central calm core of the storm is called the "Eye". The diameter of the eye varies between 30 and 50 km and is a region free of clouds with light winds. Surrounding this calm and clear eye is the "Wall Cloud Region" of the storm typified by thick clouds with torrential rain, thunder and lightning. Veering away from the Wall Cloud Region the wind speed gradually decreases, however in severe cyclonic storms, wind speeds of 50 to 60 kmph can occur at a distance of 600 km from the storm centre.
In India, cyclones affect both the Bay of Bengal and the Arabian Sea. The life span of a severe cyclonic storm in the Indian seas averages about 4 days from its initiation to the time it moves inland. The disastrous effects of cyclones include sea water inundating low lying coasts, loss of human life and live-stock, and wind damage to property. The oldest and the worst cyclone on record is that of October 1737 which hit Calcutta and took a toll of 300,000 lives in the deltaic region. It was accompanied by a 12 metre high surge and a concurrent violent earthquake.
Risk assessment of cyclones is integral for the success of safety measures and to understand the nature of past and potential cyclonic events. The website of the National Institute of Disaster Management of India reports one preventive measure as the preparation of annual hazard maps. Other measures include analyses of climatologic records to determine the frequencies, intensities and locations of tropical cyclones with respect to climate change and global warming.
Multiple tropical cyclones in the southern Indian Ocean.
B. Intensity and Frequency and Relationship to Climate Change
Dr Geoff Love is an Australian Director of Meteorology. He has submitted research to the World Meteorological Organization's Commission for Atmospheric Sciences entitled a "Statement on Tropical Cyclones and Climate Change". This paper reaffirms the finding of a 1998 study saying that any change in the frequency of tropical cyclones (hurricanes/typhoons) resulting from climate change is inconclusive due to untenable evidence and limitations within technological surveillance. The evidence that does exist indicates little or no change to the frequency of cyclones globally.
His paper also implies that the scientific community is "deeply divided" on recent studies, which suggest a substantial increase in the intensity of tropical cyclones (hurricanes/typhoons) within the past 50 years in relation to climatic changes. Some researchers believe climatology is too inconsistent to draw the aforementioned conclusion since changes in equipment and methods vary unreliably over time. The panel says it cannot come to a definitive conclusion in this "hotly debated area" and recognizes that further research is needed.
In India, cyclones affect both the Bay of Bengal and the Arabian Sea. The life span of a severe cyclonic storm in the Indian seas averages about 4 days from its initiation to the time it moves inland. The disastrous effects of cyclones include sea water inundating low lying coasts, loss of human life and live-stock, and wind damage to property. The oldest and the worst cyclone on record is that of October 1737 which hit Calcutta and took a toll of 300,000 lives in the deltaic region. It was accompanied by a 12 metre high surge and a concurrent violent earthquake.
Risk assessment of cyclones is integral for the success of safety measures and to understand the nature of past and potential cyclonic events. The website of the National Institute of Disaster Management of India reports one preventive measure as the preparation of annual hazard maps. Other measures include analyses of climatologic records to determine the frequencies, intensities and locations of tropical cyclones with respect to climate change and global warming.
Multiple tropical cyclones in the southern Indian Ocean.
B. Intensity and Frequency and Relationship to Climate Change
Dr Geoff Love is an Australian Director of Meteorology. He has submitted research to the World Meteorological Organization's Commission for Atmospheric Sciences entitled a "Statement on Tropical Cyclones and Climate Change". This paper reaffirms the finding of a 1998 study saying that any change in the frequency of tropical cyclones (hurricanes/typhoons) resulting from climate change is inconclusive due to untenable evidence and limitations within technological surveillance. The evidence that does exist indicates little or no change to the frequency of cyclones globally.
His paper also implies that the scientific community is "deeply divided" on recent studies, which suggest a substantial increase in the intensity of tropical cyclones (hurricanes/typhoons) within the past 50 years in relation to climatic changes. Some researchers believe climatology is too inconsistent to draw the aforementioned conclusion since changes in equipment and methods vary unreliably over time. The panel says it cannot come to a definitive conclusion in this "hotly debated area" and recognizes that further research is needed.
References
[1] http://www.imdmumbai.gov.in/cycdisasters.htm[2] http://www.gsdma.org/pdf/CY_Prp.pdf
[3] http://www.bom.gov.au/announcements/media_releases/ho/20060220.shtml
[4] http://www.bom.gov.au/info/CAS-statement.pdf
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