Testing on Trial: Cyclone Amphan

  • Landfall near Sagar Island in the afternoon of May 20.
  • Heavy rains along with extremely strong winds (160 - 170kmph) .
  • A surge in seawater.
  • Floods caused by tidal waves 4 - 5 m above astronomical tide.
  • Half a million people in West Bengal evacuated.
  • 100,000 in Odisha evacuated.
  • Cyclones are becoming terrifyingly unfamiliar.
  • This cyclone has washed away about 90 km in the Sunderbans alone of embankments that guarded two-thirds of islands in the South 24 Parganas district.

Aila-like situation when, in 2009

  • Cyclone՚s high intensity phase.
  • Coincided with the peak tide.
  • Causing seawater to rise 6 - 7 m.
  • Flooding paddy fields with seawater.
  • Displacing 2.3 million people.

The other two super cyclones were Kyarr in 2019 and Gonu in 2007 apart from Amphan which is the third super cyclone to occur in the North Indian Ocean region since 1999.

Reason behind the rapid intensification of Amphan

  • The amount of aerosol (pollutants) in the atmosphere in South Asia plummeted.
  • Due to the covid-19 pandemic and reduced human and economic activity.
  • This might have reduced the concentration of aerosols may have added to the already high sea surface temperatures in the Bay of Bengal.
  • It has been further revealed that atmospheric warming has twice as much effect on cyclone intensity as sea surface temperatures.
  • Rapid intensification occurs when there is an increase of maximum sustained winds of a cyclone by at least 55 km per hour within 24 hours.

Examrace Team at Aug 24, 2021