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Cyclonic Storm ‘NISARGA’

Topics Covered: Important Geophysical phenomena such as earthquakes, Tsunami, Volcanic activity, cyclone etc.

Cyclonic Storm ‘NISARGA’

What to study?

For Prelims and Mains: Tropical Cyclones- factors responsible, the process, naming and impact.

Context: Cyclonic Storm formed over East central Arabian Sea has been named Nisarga. The name in the new list was suggested by Bangladesh.

The cyclone track — issued by India Meteorological Department (IMD) authorities — show that Nisarga will cross very close to the Mumbai coast while entering the land. Maharashtra and Gujarat are on pre-cyclone alert as very heavy to extremely heavy rainfall is expected in parts of the states.

What’s next?

Conditions are favourable for intensification of the cyclone because the sea surface temperature is about 30 to 32 degrees Celsius, as compared to a normal of 28 degrees Celsius during this season. It is very likely to intensify into a Severe Cyclonic Storm during next 12 hours.

What is a cyclone?

Tropical Cyclone is any large system of winds that circulates about a center of low atmospheric pressure in a counter-clockwise direction north of the Equator and in a clockwise direction to the south. 


Cyclone formation:

  1. Cyclone is the formation of very low-pressure system with very high-speed winds revolving around it.
  2. Factors like wind speed, wind direction, temperature and humidity contribute to the development of cyclones.
  3. Before cloud formation, 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.
  4. The heat released to the atmosphere warms the air around. The air tends to rise and causes a drop in pressure. More air rushes to the centre of the storm. This cycle is repeated.

Additional facts:

  • Cyclones around the world are named by Regional Specialised Meteorological Centres and Tropical Cyclone Warning Centres. There are a total of six RSMCs and five TCWCs, including the India Meteorological Department.
  • The Indian weather bureau has been mandated with the duty to name cyclones that develop over the North Indian ocean, including Arabian Sea and Bay of Bengal, by following a standard procedure.
  • IMD released a list of cyclone names in April 2020 as suggested by the 13 countries.
  • The next few cyclones will be named Gati (named by India), Nivar (Iran), Burevi (Maldives), Tauktae (Myanmar) and Yaas (Oman).


Prelims Link:

  1. Factors responsible for the genesis of cyclones.
  2. Naming of cyclones in various regions of the world.
  3. Why more cyclones in Eastern coast of India?
  4. What is coriolis force?
  5. What is latent heat of condensation?

Mains Link:

Discuss the factors responsible for the formation of tropical cyclones. All about tropical cyclones:

Sources: pib.