Why in news?
- The National Weather Forecasting Centre/Cyclone Warning Divisionof the India Meteorological Department said – The Landfall process has commenced for the Super Cyclonic Storm ‘AMPHAN’ (pronounced as UM-PUN) and the forward sector of the wall cloud region is entering into land in West Bengal.
- After landfall, the system is likely to move north-eastwards close to Kolkata.
Structure of a Cyclone
A cyclone’s center, known in a mature tropical cyclone as the eye, is the area of lowest atmospheric pressure in the region.
Near the center, the pressure gradient force and the force from the Coriolis effect must be in an approximate balance, or the cyclone would collapse on itself as a result of the difference in pressure.
The eye of the storm is the centre. It’s a relatively calm space. When the eye passes over an area, winds slow down and everything feels like it has cleared up. But this is the proverbial calm before the storm, as the part that comes after the eye usually inflicts the most damage.
This is where the most effective part of a cyclone rests. The eyewall houses extremely high wind speeds, causing damage to both lives and property. It is a ring of thunderstorms, and changes in the eye or the eyewall affects the storm’s intensity.
These are the outer parts of a cyclone where sudden bursts of rain happen. There can also be gaps betwen rainbands where no rain or wind occurs.
Landfall, What happens when a Cyclone reaches land from the ocean?
- Tropical cyclones dissipate when they can no longer extract sufficient energy from warm ocean water.
- A storm that moves over land will abruptly lose its fuel source and quickly lose intensity.
- A tropical cyclone can contribute to its own demise by stirring up deeper, cooler ocean waters. tropical cyclone can contribute to its own demise by stirring up deeper, cooler ocean waters.