What is Cyclone Biparjoy and how was it named?

• A cyclonic storm, named Biparjoy, has developed in the Arabian Sea.
• The cyclone is predicted to gain in strength over the next three days and develop into a very severe cyclonic storm by June 13.

How are cyclones named

• ‘Biparjoy’ was suggested by Bangladesh and the word means ‘disaster’ or ‘calamity’ in Bengali.
• The naming of cyclones is done by countries on a rotational basis, following certain guidelines.
  • Worldwide, there are six regional specialised meteorological centres (RSMCs) and five regional Tropical Cyclone Warning Centres (TCWCs) mandated for issuing advisories and naming of tropical cyclones.
  • Indian Meteorological Department is one of the six RSMCs to provide tropical cyclone and storm surge advisories to 13 member countries under the WMO/Economic and Social Commission for Asia-Pacific (ESCAP) Panel including:
    • Bangladesh, India, Iran, Maldives, Myanmar, Oman, Pakistan, Qatar, Saudi Arabia, Sri Lanka, Thailand, United Arab Emirates and Yemen.
  • RSMC, New Delhi is also mandated to name the Tropical Cyclones developing over the north Indian Ocean (NIO), including the Bay of Bengal (BoB) and the Arabian Sea (AS).
  • So, the tropical cyclones forming over different Ocean basins are named by the concerned RSMCs & TCWCs.

The process:

• Some rules are to be followed while naming cyclones, such as:
  • The proposed name should be neutral to
    • politics and political figures
    • religious believes
    • cultures
    • gender
  • Name should be chosen in such a way that it does not hurt the sentiments of any group of population over the globe
  • It should not be very rude and cruel in nature
  • It should be short, easy to pronounce and should not be offensive to any member
  • The maximum length of the name will be eight letters

What is a cyclone?

• 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.
• In fact, that is one of the main reasons why we see a greater number of cyclones in the Bay of Bengal compared to the Arabian Sea.
• The Bay of Bengal is slightly warmer.
• Because of climate change, the Arabian Sea side is also getting warmer.
• As a result, the number of cyclones in the Arabian Sea is showing an increasing trend in the recent trend.

Formation of cyclone

• As air warms over hotter regions, it ascends, leading to low pressure at the surface it is covering.
• When air cools in colder areas it descends, leading to high pressure at the surface.
• In a depression or low-pressure situation, the air is rising and blows in an anticlockwise direction around the low in the northern hemisphere and in a clockwise direction in the southern hemisphere.
• This is because of the Coriolis effect, a result of the earth’s rotation on its axis.
• As warm air rises and cools, water vapour condenses to form clouds and this can lead to rains.

Prelims Takeaway

• Cyclones
• IMD
• WMO