by Rajshri Ravichandran
One of the most dangerous weather phenomena are tropical cyclones. They are powerful rotating storms with maximum wind speeds reaching 119 kph and torrential rainfall that develop over warm tropical oceans. Furthermore, secondary phenomena like storm surges, flooding, landslides, and tornadoes cause far more harm to people and infrastructure than wind alone. Based on the region of the world they form, several names are given to tropical cyclones. The Atlantic Ocean and the eastern north Pacific Ocean both experience hurricane occurrence. In the western Pacific Ocean, typhoons emerge. The South Pacific Ocean and the Indian Ocean both have tropical storm formations.
Source: Encyclopedia Britannica
More than 90% of the heat produced by greenhouse gas emissions is absorbed by the ocean and which raises the temperature of the waters.
Increasing temperatures contribute to an increase in the frequency of severe storms since cyclones get their power through warm oceans. Severe storms from cyclones might become much more destructive and devastating as a consequence of increasing sea levels. The Arabian Sea had two to three weak cyclones a year on average. Global warming-related increases in ocean temperature are changing that. The Arabian Sea has had pre-monsoon cyclones for four straight years for the very first time since satellite observations began in India in 1980.
Source: The Economic Times
Over the past two decades, cyclones have formed over the Arabian Sea more frequently and with more force than they have across the Bay of Bengal. According to a study, between 2001 and 2019 there was a 52% increase in the number of cyclones across the Arabian Sea and an 8% drop across the Bay of Bengal. Over the last two decades, there have been 150% more extremely strong cyclones in the Arabian Sea. Global warming has caused a sharp rise in surface warming in the Arabian Sea over the past century. The current temperature is 1.2–1.4 °C warmer than it was forty years ago. Active convection, copious rainfall, and powerful cyclones are all supported by these higher temperatures.
Source: The Hindu
The Bay of Bengal has long been a cyclone potential source. Eight of the 10 most destructive tropical cyclones in history have their origins in this area. In accordance with a study on severe weather events, India was affected by up to 117 cyclones in the 50 years between 1970 and 2019 and more than 4 lakh people perished. Three lahks to five lakh persons were massacred when the Great Bhola Cyclone struck the East Pakistani shores (now Bangladesh) on November 11, 1970. The storm’s death toll is the highest known to date. According to the University of Rhode Island, more than 45% of the city of Tazumuddin’s 1,67,000 inhabitants were murdered. The storm surge’s highest height was reported to be close to 35 feet, resulting in significant damage.
Source: Republic World
An IMD report identifies Sundarbans as India’s cyclone capital, and the South 24 Parganas division of West Bengal, which contains the majority of the Indian Sundarbans, as the region greatest commonly affected by cyclones. The triangular form of the bay, which functions as a vortex and generates significant coastal flooding, can also be blamed for the exceptionally high number of cyclone-related deaths in the Bay of Bengal. The low-lying sections of coastal regions frequently flood because the shallow bay bottom provides for more surges.
India has been able to dramatically lower the death toll from cyclones due to timely warnings, the establishment of disaster relief teams, and an improved escape method, among other factors.
- “Tropical Cyclones”, World Health Organization.
- “More cyclones in Arabian Sea in recent years”. The Hindu, December 09, 2021.
- “Tropical cyclones in the Arabian Sea: Why are they increasing?”. The Economic Times, May 17, 2021.
- Seema Prasad , “Fewer cyclones in Bay of Bengal but frequency increased in Arabian Sea: Report”. Down To Earth, October 28, 2022.
- Deekshith Nevil Pinto, “A Brief History of Deadly Bay of Bengal Cyclones That Have Caused 80% of World’s Cyclone-Related Deaths”. The Times of India, May 26, 2021.