Preparedness Pays off: On Cyclone Biparjoy

Context:

Recently, a cyclonic storm, Biparjoy, swept through Gujarat and parts of Rajasthan.

About Cyclone Biparjoy:

• Biparjoy’ was suggested by Bangladesh and the word means ‘disaster’ or ‘calamity’ in Bengali.
• The storm was also categorized as falling in the ‘very severe’ category — average wind speeds of over 115 kmph.

Mechanism of Cyclone Formation:

• Essentially, Cyclone is a system of high speed winds rotating around a low-pressure area, with the winds blowing counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.
• A mature tropical cyclone is characterized by the strong spirally circulating wind around the centre, called the eye.
• The eye is a region of calm with subsiding air. Around the eye is the eye wall, where there is a strong spiraling ascent of air to greater height reaching the tropopause.
• The energy that intensifies the storm, comes from the condensation process in the towering cumulonimbus clouds, surrounding the centre of the storm. 
• With continuous supply of moisture from the sea, the storm is further strengthened. 
• On reaching the land the moisture supply is cut off and the storm dissipates.

Image Credits: NCERT

Naming of Cyclones:

• Cyclones that form in every ocean basin across the world are named by:
  • the Regional Specialized Meteorological Centres (RSMCs) and Tropical Cyclone Warning Centres (TCWCs). 
• There are six RSMCs in the world, including the India Meteorological Department (IMD), and five TCWCs.
• As an RSMC, the IMD names the cyclones developing over the north Indian Ocean, including the Bay of Bengal and Arabian Sea, after following a standard procedure.
• In 2000, a group of nations called WMO/ESCAP (World Meteorological Organisation/United Nations Economic and Social Commission for Asia and the Pacific), decided to start naming cyclones in the region. 
  • It comprises Bangladesh, India, the Maldives, Myanmar, Oman, Pakistan, Sri Lanka and Thailand.
  • After each country sent in suggestions, the WMO/ESCAP Panel on Tropical Cyclones (PTC) finalized the list.
  • The list of 169 cyclone names released by IMD in 2020 were provided by these countries — 13 suggestions from each of the 13 countries.

Why is there more rise  in  development of cyclones in the Arabian sea in recent times?

• A cyclone is a low-pressure system that forms over warm waters. 
• Usually, a high temperature anywhere means the existence of low-pressure air, and a low temperature means high-pressure wind. 
• Because of climate change, the Arabian Sea side is also getting warmer, and as a result, the number of cyclones in the Arabian Sea is showing an increasing trend in the recent trend.

Way Forward:

• Frequent evacuation cannot be implemented as a permanent policy intervention and efforts must be made to ensure that coastal-regulation-zone norms that prescribe the kind of structures permissible at specific distances from the shoreline must be strictly implemented. 
• The dwellings of rural, coastal inhabitants must be strengthened and natural bulwarks such as mangroves at wetlands must be buttressed for improved resilience.

News Source: The Hindu

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