Cyclone Mocha

May 12, 2023

The India Meteorological Department (IMD) recently issued a bulletin forecasting that cyclone Mocha is expected to intensify into a severe storm.

About Cyclone Mocha:
It is a tropical cyclone formed over the southern Bay of Bengal.
The cyclone's name ‘Mocha’ is suggested by Yemen and was named after the Red Sea port city, which is known to have introduced coffee to the world.
How a Tropical Cyclone Formed?
- A tropical cyclone is formed only over warm ocean waters near the equator.
- Warm, moist air rises up and away from the ocean surface, creating an area of low pressure.
- It causes the air from surrounding areas with higher pressure to move towards the low-pressure area.
- This leads to the warming up of air and causes it to rise above.
- As the air rises & cools, the water in the air forms clouds.
- This complete system of clouds and wind spins & grows, along with the ocean’s heat.
- As the wind rotation speed increases, an eye gets formed in the middle.
Characteristics of a Tropical Cyclone:
- The centre of a cyclone is very calm and clear with very low air pressure.
- The average speed is 120 kmph.
- They have closed isobars which leads to greater velocity. Isobars are imaginary lines on a weather map that connect locations with equal atmospheric pressure.
- They develop over oceans and seas only.
- They move from east to west under the influence of trade winds.
- They are seasonal in nature.
How are Cyclones Classified? Cyclones are classified on the basis of wind speed by the Indian Meteorological Department (IMD):
- Depression: Wind speeds of between 31–49 km/h
- Deep Depression: Between 50-61 km/h
- Cyclonic Storm: Between 62–88 km/h
- Severe Cyclonic Storm: Between 89-117 Km/h
- Very Severe Cyclonic Storm: Between 118-166 Km/h
- Extremely Severe Cyclonic Storm: Between 166-221 Km/h
- Super Cyclonic Storm: Above 222 Km/h