Hotter oceans would lead to super cyclones. How has the lockdown incre...
May 21, 2020
Hotter oceans would lead to super cyclones. How has the lockdown increased the warming of the oceans creating super cyclones? Elaborate.
Higher than normal temperatures in the Bay of Bengal (BoB) may be creating ‘super cyclones’ and the lockdown, indirectly, may have played a role.
Super cyclone Amphan that is barrelling towards West Bengal is the strongest storm to have formed in the BoB since the Super Cyclone of 1999 that ravaged Paradip in Odisha.
Cyclones gain their energy from the heat and moisture generated from warm ocean surfaces.
This year, the BoB has posted record summer temperatures, a fall-out, of global warming from fossil fuel emissions that has been heating up oceans.
The BoB has been particularly warm. Some of the buoys have registered maximum surface temperatures of 32-34°C consecutively, for the first two weeks of May.
While tropical cyclones in these seas are a typical feature of the summer months and play a role in aiding the arrival of the monsoon, warming around India is not longer restricted to just the BoB but also the Arabian Sea and the Indian Ocean.
This makes storm prediction less reliable as well as disrupting monsoon patterns.
The elevated ocean temperatures this year could, in part, be explained by the lockdown.
Reduced particulate matter emissions during the lockdown meant fewer aerosols, such as black carbon, that are known to reflect sunlight and heat away from the surface.
Every year, increased particulate pollution from the Indo-Gangetic plains is transported towards the BoB and this also influences the formation of clouds over the ocean.
Fewer clouds and more heat in the Bay of Bengal may have amplified the strength of the cyclone.
It is observed that during the lockdown from March-April, BoB temperatures have been 1-3°C higher than normal.