Cyclone Remal to reach West Bengal, Bangladesh coasts by Sunday evening: IMD

Fisherfolk out at sea have been advised to return to the coast and not venture into the Bay of Bengal until May 27.Scientists say cyclonic storms are intensifying rapidly and retaining their potency for longer periods due to warmer sea surface temperatures, a result of oceans absorbing most of the excess heat from greenhouse gas emissions.The past 30 years have witnessed the highest sea surface temperatures since records began in 1880.

According to senior IMD scientist DS Pai, warmer sea surface temperatures mean more moisture, which is favourable for the intensification of cyclones.Madhavan Rajeevan, former secretary of the Union Ministry of Earth Sciences, said a sea surface temperature of 27 degrees Celsius and above is needed for a low-pressure system to intensify into a cyclone.

The sea surface temperature in the Bay of Bengal is around 30 degrees Celsius at present.”The Bay of Bengal and the Arabian Sea are very warm at present, so a tropical cyclone can easily form,” Rajeevan said.But tropical cyclones are not only controlled by the ocean; the atmosphere also plays an important role, especially in terms of vertical wind shear — a change in wind speed and/or wind direction with altitude.

”A cyclone will not intensify if the vertical wind shear is very large. It will weaken,” Rajeevan said.Models suggest the cyclone will not affect the monsoon progress, the senior meteorologist said.Pai, however, said it could affect the progress of the monsoon in some parts.

He told PTI, ”Initially, the system will help the monsoon progress over the Bay of Bengal. Thereafter, it will detach from the monsoon circulation and pull a lot of moisture, which could result in a slight delay in the monsoon progress in that area.”