The north Indian Ocean is known for deadly cyclones since cyclones have been recorded. However, in the last decade, cyclones are showing a tendency of intensifying rapidly in a very short time. Such a trend has produced frequent devastating cyclones in both the east and the west coast of the country. Though there were many intense cyclones in the past, they were much rarer compared to what we see in the last few years. It is expected that global warming has a contribution to it. The question is, in what way!
North Indian Ocean sees an average of 5 cyclones a year. However, cyclones tend to form mainly in the Bay of Bengal and during May and October. The chance of cyclone formation in the rest of the year and in the Arabian Sea is comparatively much less. The latest trend shows that cyclones are scattered throughout the year, while more than one cyclone can exist at the same time in different parts of the north Indian Ocean. There is also a trend of cyclones showing sudden explosive intensification or less chance of weakening before hitting the coast. Moreover, the relatively quieter Arabian Sea has seen a sudden growth in cyclones and erratic rainfall (sudden hefty rain followed by drought) in recent years. Let us discuss these with examples.
Taking the year 2013, we all remember the cyclone Phailin causing havoc in south Odisha and north Andhra Pradesh. Phailin developed as a precursor low from the South China Sea. Two more cyclones followed, Helen and Lehar, both having their roots in typhoons of the South China Sea. So, we can see that the Bay of Bengal itself was not responsible for forming these cyclones. Except Phailin, Helen, Lehar, Madi and all other cyclones weakened before landfall. And the Arabian Sea was much quieter with the formation of just one depression.
In 2019, the earliest formed tropical cyclone, Pabuk, entered the Andaman Sea from the Gulf of Thailand on 4th January. The destructive Fani formed in late April close to Sumatra. Fani intensified rapidly from a cyclonic storm to an extremely severe cyclonic storm in less than 48 hours. Such rapid intensification started trends of rapidly intensifying cyclones in the North Indian Ocean. Very severe cyclonic storm Vayu, extremely severe cyclonic storm Maha, and super cyclonic storm Kyarr spared the lands as they turned away from land and fizzed out in the sea. The basin also saw rarest of its kind cyclones Kyarr and Maha, raging at the Arabian Sea at the same instant. Also, cyclones Maha in the Arabian Sea and Bulbul in the Bay of Bengal form and develop simultaneously. IMD called these two phenomena rarest of rarest. Such phenomenon of two cyclones existing simultaneously at the same basin was observed for the first time in 2018 when very severe cyclonic storms Luban and Titli raged the Arabian Sea and Bay of Bengal at the same time, and cyclones Mekunu following the heels of cyclone Sagar in the Arabian Sea.
Amphan in 2020 was one of the strongest cyclones to be ever formed in the Bay of Bengal, and comparative to the 1999 Odisha cyclone. Amphan intensified beyond recognition from a cyclonic storm to a super cyclone in less than 24 hours. The rapid intensification of Amphan proved beyond doubt that cyclones are turning more devastating in recent years. Gati, which followed in the autumn of 2020, also underwent rapid intensification from 65km/hr to 185km/hr in just 12 hours. Cyclone Tauktae was initially expected to be much less intense, which underwent rapid intensification overnight before making landfall in Gujarat in 2021.
There have also been instances of cyclones changing paths just before landfall, giving little time for preparation. Cyclone Tauktae was initially forecasted to spare the Indian coast and move towards Pakistan or hit the coast near Dwarka. It changed the track after intensification and reached the Diu coast much before the anticipated time. Cyclone Ockhi of 2017 didn’t show any signs of intensification until near Kanyakumari, when it suddenly intensified rapidly before forecasted, causing fishers in the sea to be caught by surprise. Amphan too steered more towards the metropolitan city of Kolkata than anticipated causing massive destruction in the city.
Two tornadoes formed due to cyclone Yaas, one in Bandel and another in Ashoknagar of West Bengal, caused significant destruction to these places. Tornadoes are extremely rare in the North Indian Ocean but have recently surfaced here. The first considerable tornado recorded was formed in Cyclone Nisarga that struck Alibaug near Mumbai in 2020. Tornadoes are previously not forecasted, and hence, they are more dangerous to the public. Their place and time of formation are still unpredictable since tornadoes are a new entity in this basin.
The most destructive feature of a landfalling cyclone is the storm surge. Lakhs of people are to be evacuated from low lying and erosion-prone areas and are relocated to cyclone shelters before a storm hits the land. However, many villagers do not want to leave their land, and thus cause destruction. In 2020 and 2021, most of these cyclone shelters are being used for Covid-19 treatment. Thus arises the need for new cyclone shelter locations, which hardly exist in remote villages. Storm surge of Fani, Amphan, Tauktae, and Yaas caused significant damage along the coast. Seawater reached areas far from the sea, damaging crops, livestock, forests and houses. Amphan and Yaas breached several earthen dams, which were previously never breached before. Both Amphan and Yaas reached mangrove island areas in eastern India that are rural, remote, but heavily populated. Covid-19 restrictions at the time of landfall of these cyclones hampered people movement, thus causing more damage than anticipated. Tauktae moved parallel to the west coast, flooding most of it in Tamil Nadu, Kerala, Karnataka, Goa and Maharashtra before reaching the Gujarat coast.
Also, desert areas of Yemen, Oman and Arabia, which are more prone to floods, are experiencing a sudden growth of cyclones. Even moderate rainfall in deserts is enough to cause catastrophic floods as the sandy soil is not accustomed to holding moisture. Cyclone Mekunu caused seven years worth of rain in a single day in parts of Yemen. Back to back cyclones of Chapala and Megh in 2015 caused record-breaking rainfall and flash floods in Socotra island and Yemen and Somalia overall. Cyclone Hikaa in 2019 and cyclone Ashobaa in 2015 and the super cyclone Gonu way back in 2007 reached the Omani coast dumping years’ worth of rain, floods and destruction.
Minimizing global warming, deforestation, and curbing air pollution can be a long term solution, but what is in need of the hour is short term solutions. The Government has to take the initiative to build more cyclone shelters all along the coast and in the islands as the place is entirely safe from cyclone landfalling. The earthen dams are needed to be repaired at frequent intervals as their destruction has also become more frequent. The houses are to be built only in higher areas in the coastal plains. Illegal occupation of land by hotel and tourist companies along the coast needed to be stopped as such construction only loosens the topsoil that can be easily eroded. Most importantly, people need to be aware of the growth of devastating cyclones to protect themselves and lend a hand in rescuing others who are in need.
Written by – Himadri Paul