- As per National Disaster Management Authority (NDMA), cyclones result from atmospheric disturbances surrounding a low-pressure area characterised by rapid and often destructive air circulation
- Air circulation- The air circulates inward in an anticlockwise direction in the Northern Hemisphere and clockwise in the Southern Hemisphere.
- Occurrence- Cyclonic winds move across nearly all regions of the Earth except the equatorial belt.
- Conditions of the cyclone-
- Large and continuous supply of warm and moist air that can release enormous latent heat.
- Strong Coriolis force that can prevent filling of low pressure at the centre (absence of Coriolis force near the equator prohibits the formation of tropical cyclone between 0 -5 latitude).
- Unstable condition through the troposphere that creates local disturbances around which a cyclone develops.
- Absence of strong vertical wind wedge, which disturbs the vertical transport of latent heat
- Cause- By atmospheric disturbances around a low-pressure area distinguished by swift and often destructive air circulation.
- Eye of the cyclone- Low-pressure center of the cyclone
- The lower the pressure in the eye, the more intense is the cyclone.
- Eye-wall- Surrounds the eye with the strongest winds and heaviest rain and is the most destructive part of the cyclone.
- Storm surge- The abnormal rise in sea level due to cyclonic storms.
- Cyclone prone areas- India’s east and west coasts are affected by cyclones annually, mostly in pre-monsoon and post-monsoon seasons.
- Indian tropical storms- Climatologically, about 5 cyclones develop in the North Indian Ocean basin comprising the Bay of Bengal and the Arabian Sea every year.
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