It’s May, and for the second year running, a major pre-monsoon cyclone is set to make landfall in the next few days. Cyclone Tauktae in the Arabian Sea, which is currently classed as a cyclonic storm (CS) by the India Meteorological Department (IMD), is set to develop into a very severe cyclonic storm (VSCS) over the next two days. It is predicted to make landfall along the Gujarat coast either on 17 or 18 May. The cyclone, which developed as a depression over Lakshwadeep, has prompted the IMD to issue ‘Red’ alerts for Kerala on 14 May and for Karnataka and Tamil Nadu on 15 May. It has also issued a heavy rain warning for Maharashtra and Gujarat as the cyclone gathers more strength. The National Disaster Response Force (NDRF) has created 53 teams to tackle the fallout of the cyclone.
Depression over Lakshadweep area near latitude 11.0°N and longitude 72.5°E, about 30 km south-southwest of Amini Divi, To intensify into a Cyclonic Storm in next 24 https://t.co/83HTlHnJJU move move north-northwestwards and reach near Gujarat coast by 18th May morning. pic.twitter.com/qGO44bktRi— India Meteorological Department (@Indiametdept) May 14, 2021
As global warming gathers pace, intense cyclones from the Bay of Bengal and the Arabian Sea are making landfall with greater frequency every year. As we must remember, 2020 was the year of cyclones. Almost exactly a year ago, cyclone Amphan formed over the Bay of Bengal and travelled at great speed towards to the Bengal coast, turning into a super cyclone in 24 hours. It was supercharged by gathering energy from the anomalously high sea surface temperatures in the Bay of Bengal. About a week after Amphan caused widespread havoc in West Bengal, cyclone Nisarga formed over the Arabian Sea and struck the Maharashtra coast as a destructive storm front. In the post-monsoon season, cyclone Nivar hit the Coromandel coast at Puducherry.
The fact that cyclones are increasing due to climate change is borne out by a record that Cyclone Tauktae has created. Since satellite records began in India in 1980, this is the first time that pre-monsoon cyclones have been recorded in the Arabian Sea for four consecutive years. It is now a well known fact that the global ocean has absorbed 90% of the excess heat generated by greenhouse gas (GHG) emissions since 1970. This has led to anomalous ocean warming, which in turn makes cyclones intensify rapidly.
For the first time in satellite era (1980 onwards), 4 consecutive years (2018,2019,2020 and 2021) will see cyclone in the Arabian Sea in pre-monsoon season (April-June). Attached satellite pic showing the system organizing in the Arabian Sea. Data and satellite image credits:IMD pic.twitter.com/fcqDobOqzi— vineet kumar (@vineet_tropmet) May 14, 2021
Speaking to Lounge in November last year when cyclone Nivar made landfall, climate scientist Roxy Mathew Koll of the Indian Institute of Tropical Meteorology (IITM) in Pune had noted that the reason cyclones are also intensifying so rapidly is because of unprecedented high temperatures over the Indian Ocean (Bay of Bengal and the Arabian Sea). “Heat is energy, and cyclones intensify rapidly by turning the potential energy stored in the ocean to kinetic energy,” he said.
A paper Koll co-authored in 2014 for the American Meteorological Society’s Journal Of Climate, noted that “the western tropical Indian Ocean has been warming for more than a century, at a rate faster than any other region of the tropical oceans, and turns out to be the largest contributor to the overall trend in the global mean sea surface temperature (SST).”
1/ Arabian Sea used to be cool, but now it's a warm pool—supporting more intense cyclones. Tropical cyclones draw their energy from the warm waters—a reason why they form over the warm pool regions where temperatures are above 28°C.— Roxy Koll ⛈ (@rocksea) May 12, 2021
More on WIO warming: https://t.co/2jieMud3Ac pic.twitter.com/lAjKwwMiDz
Koll noted in a social media post on 12 May, just days before the formation of cyclone Tauktae, that “Arabian Sea used to be cool, but now it's a warm pool—supporting more intense cyclones. Tropical cyclones draw their energy from the warm waters—a reason why they form over the warm pool regions where temperatures are above 28°C.” The IMD, in its bulletin on cyclone Tauktae has noted that sea surface temperature over the Arabian Sea is anomalously high right now, at 30-31 degree Celsius. The speed at which Tauktae is intensifying also bears out the effect of global warming.