In the last couple of years, the frequency and intensity of cyclones has increased drastically, leading to a devastating impact on the lives of those living in the coastal region. According to a recent study by Indian scientists, the intensity of severe cyclonic storms in the North Indian Ocean region has been increasing over the last four decades.
Although cyclones in the Bay of Bengal have been a regular occurrence, they are also increasing in western India, amid rising temperatures in the Arabian Sea and, according to experts, climate change is the reason.
"The increasing intensity of severe cyclonic storms with major socioeconomic implications was due to atmospheric parameters like higher relative humidity, especially at mid atmospheric level, weak vertical wind shear as well as warm sea surface temperature (SST). This indicates the role of global warming in bringing about this increasing trend," India's Science and Technology Ministry said in a statement on Thursday.
Since the Super Cyclone that hit India's Odisha state in 1999 to Cyclone Yaas earlier this year, the country has witnessed over 10,000 deaths. According to reports, since 1970, India has been struck by over 117 cyclones. In the past two years, the country has recorded eight cyclones out of which five took place in the Arabian sea. Cyclone Tauktae is the third consecutive cyclone, after Vayu in 2019 and Nisarga in 2020, and the most severe India's western coast has witnessed since 1902.
The Ministry also stated that the impact of global warming, due to climate change and its effect on extreme weather events, such as the increasing frequency of high-intensity tropical cyclones forming over global ocean basins is a matter of concern. "High-intensity cyclones have become more frequent in the North Indian Ocean, causing significant risk and vulnerability to the coastal region," it added.
Jiya Albert, Athira Krishnan and Prasad K. Bhaskaran, from the Department of Ocean Engineering & Naval Architecture, IIT Kharagpur, along with other prominent scientists from Indian institutes have studied the role and influence of critical atmospheric parameters in the large-scale environmental flow, and El Niño–Southern Oscillation (ENSO) on tropical cyclone activity in the North Indian Ocean.
The exhaustive research has revealed that there is an increase in tropical cyclones formed during the pre-monsoon season. This increasing trend was also found to be substantial in both the Bay of Bengal and the Arabian Sea basins, since 2000.
"Strong mid-level relative humidity (RH), positive low-level relative vorticity (RV), weak vertical wind shear (VWS), warm sea surface temperature (SST), and suppressed outgoing longwave radiation (OLR) are responsible for the increased tropical cyclone activity in the North Indian Ocean," the climate study revealed.
The recent cyclones Tauktae and Yaas substantiate this pattern, and indicates that India’s eastern and western coasts are becoming more vulnerable as climate change leads to sea level rise that is a result of the polar ice cap melt-off.