How Biparjoy became the longest-lived cyclone, why it took 10 days to make landfall in Gujarat?

Severe Cyclone Biparjoy left a trail of destruction as destructive wind speeds of up to 140 kmph and rains wreaked havoc in Kutch and parts of Saurashtra region of Gujarat.

The devastating Cyclone made landfall in Gujarat on Thursday evening after a 10-day journey across the Arabian Sea. The storm started on June 4 and had been moving slowly north in the Arabian Sea for 10 days before it hit the land on June 14.

The cyclone Biparjoy started in June 4 with a wind speed of 50 kmph gained speed of 190 kmph on June 11 and hit the land areas with a sustained winds speed of 125-140 kilometers per hour, however, it began to weaken several hours later, and by 2:30 am on Friday, its winds had decreased to 100 kilometres per hour with gusts up to 110 kilometres per hour.


But why did cyclonic Biparjoy spend a long time across the Arabian Sea?

Scientists believe that warm sea surface temperatures helped Cyclone Biparjoy to last longer than any other cyclone in the Arabian Sea in the recent history. Biparjoy became the longest-lived cyclone in the basin, overtaking Cyclone Kyarr in 2019, which lasted nine days and 15 hours.

“"The oceans have become warmer on account of climate change. In fact, a recent study shows that the Arabian Sea has warmed up by almost 1.2-degree Celsius since March, thus the conditions are very much favourable for the rapid intensification of the system so it has potential to sustain the strength for a longer period,” said Raghu Murtugudde, an Earth system scientist at the Department of Atmospheric and Oceanic Science, University of Maryland and IIT Bombay.

Another study titled "Changing status of tropical cyclones in the north Indian Ocean", in 2021, found that the frequency, duration and intensity of cyclones in the Arabian Sea increased significantly between 1982 and 2019, hesaid.

The intensity of cyclones has increased in the Arabian Sea by about 20 per cent (post-monsoon) to 40 per cent (pre-monsoon). There has been a 52 per cent increase in the number of cyclones in the Arabian Sea, while very severe cyclones have increased by 150 per cent.

"Climate models are unable to pick up this rapid intensification of cyclones because they do not include ocean conditions properly and that is their limitation. Cyclones nowadays can retain their energy for quite a long number of days. One example of this trend was Cyclone Amphan which continued to travel over land as a strong cyclone and resulted in massive devastation.

"As long as oceans are warm and winds are favourable, cyclones will retain their intensity for a longer period," said Roxy Mathew Koll, Climate Scientist at the Indian Institute of Tropical Meteorology and Lead IPCC Author.

Cyclone Tauktae in 2021 was the last severe cyclone that made landfall in the region. It claimed 174 lives, a relatively low figure, thanks to extensive preparations ahead of the storm.

In 1998, a cyclone that hit Gujarat state claimed more than 1,000 lives and caused extensive damage. A cyclone that hit Sindh province and Karachi in 1965 killed more than 10,000 people.

(Inputs from AP and IANS)