NEW LIST OF NAMES OF TROPICAL CYCLONES OVER NORTH INDIAN OCEAN

Why in news?

In September, 2018 it was decided to prepare a fresh list of names of tropical cyclones, and the report was finally adopted by WMO/ESCAP PTC with consensus in April, 2020.

The names of cyclones that may emerge in the future in India are Gati, Tej, Murasu, Aag, Vyom, Jhar, Probaho, Neer, Prabhanjan, Ghurni, Ambud, Jaladhi and Vega, according to the report.

Important Background Details

• 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.
• The India Meteorological Department is one of the six Regional Specialised Meteorological Centres (RSMCs) to provide tropical cyclone and storm surge advisories to 13 member countries under WMO/ESCAP PTC Panel (World Meteorological Organization / The United Nations Economic and Social Commission for Asia and the Pacific – Panel on Tropical Cyclones PTC).

WMO/ESCAP Panel includes the following 13 member countries:

1. India,
2. Bangladesh,
3. Iran,
4. Maldives,
5. Myanmar,
6. Oman,
7. Pakistan,
8. Qatar,
9. Saudi Arabia,
10. Sri Lanka
11. Thailand
12. United Arab Emirates
13. Yemen

• 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).
• The tropical cyclones forming over different Ocean basins are named by the concerned RSMCs & TCWCs.
• For north Indian Ocean including Bay of Bengal and Arabian Sea, the RSMC, New Delhi assigns the name to tropical cyclones following a standard procedure.

What is the use of Naming of Tropical Cyclones?

Naming of Tropical Cyclones helps the scientific community, disaster managers, media and general masses to

• identify each individual cyclone.
• create awareness of its development.
• remove confusion in case of simultaneous occurrence of TCs over a region
• remember a TC easily
• rapidly and effectively disseminate warnings to much wider audience.

Criteria Adopted for Naming Cyclones

1. The proposed name should be neutral to (a) politics and political figures (b) religious believes, (c) cultures and (d) gender
2. Name should be chosen in such a way that it does not hurt the sentiments of any group of population over the globe
3. It should not be very rude and cruel in nature
4. It should be short, easy to pronounce and should not be offensive to any member
5. The maximum length of the name will be eight letters
6. The proposed name should be provided alongwith its pronunciation and voice over
7. The Panel reserves the right to reject any name, if any of the criteria above is not satisfied.
8. The finalised names may also be reviewed during the course of time of implementation with the approval of PTC in its annual session, in case any reasonable objection is raised by any member
9. The names of tropical cyclones over the north Indian Ocean will not be repeated. Once used, it will cease to be used again.

Tropical cyclone

• A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain or squalls.
• Depending on its location and strength, a tropical cyclone is referred to by different names:
  • Cyclones in the Indian Ocean
  • Hurricanes in the Atlantic
  • Typhoons in the Western Pacific and the South China Sea
  • Willy-willies in Western Australia

• “Tropical” refers to the geographical origin of these systems, which form almost exclusively over tropical seas.
• “Cyclone” refers to their winds moving in a circle, whirling round their central clear eye, with their winds blowing counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.
• The opposite direction of circulation is due to the Coriolis effect.

Formation of Tropical Cyclones

• Tropical cyclones typically form over large bodies of relatively warm water.
• They derive their energy through the evaporation of water from the ocean surface, which ultimately recondenses into clouds and rain when moist air rises and cools to saturation.
• Water takes up heat from the atmosphere to change into vapour.
• When water vapour changes back to liquid form as raindrops, this heat is released to the atmosphere.
• The heat released to the atmosphere warms the air around.
• The air tends to rise and causes a drop in the pressure.
• More air rushes to the centre of the storm.
• This cycle is repeated.