Mocha: Summer cyclones not new; Fani, Amphan were May storms too
Mocha: Summer cyclones not new; Fani, Amphan were May storms too
Subject : Geography
Section: climatology
Context:
A summer cyclone is likely to take place in the Bay of Bengal around May 8, called Mocha. India has seen a few major cyclones in the Bay of Bengal during April and May in the last few years.
However, according to data from the India Meteorological Department (IMD), October and November constitute the peak cyclone season for India.
Concept –
- A tropical cyclone is an intense circular storm that originates over warm tropical oceans and is characterized by low atmospheric pressure, high winds, and heavy rain.
- A characteristic featureof tropical cyclones is the eye, a central region of clear skies, warm temperatures, and low atmospheric pressure.
- Storms of this type are called hurricanesin the North Atlantic and eastern Pacific and typhoons in South-East Asia and China. They are called tropical cyclones in the southwest Pacific and Indian Ocean region and Willy-willies in north-western
- Storms rotate counter-clockwise in the northern hemisphere and clockwise in the southern
The conditions favourable for the formation and intensification of tropical storms are:
- Large sea surface with temperature higher than 27° C.
- Presence of the Coriolis force.
- Small variations in the vertical wind speed.
- A pre-existing weak low-pressure area or low-level-cyclonic circulation.
- Upper divergence above the sea level system.
Some of the other recent summer cyclones that hit India
Cyclone Fani, May 2019
Fani is considered the worst cyclone to hit Odisha in this century. It was also the longest-lived cyclone in the Bay of Bengal ever observed.
The extended storm period went on for 11 days in the sea and land put together. What made it even more surprising was that it had formed in the pre-monsoon season, in April
Super Cyclone Amphan, May 2020
Amphan was the first super cyclone in the Bay of Bengal in the last 21 years and made landfall near Digha in West Bengal on May 20, 2020. It ravaged almost the entirety of south Bengal, including Kolkata.
Warm subsurface waters in the Bay of Bengal likely helped fuel it. Marine heat waves also likely helped intensify the cyclone from Category 1 (cyclonic storm) to Category 5 (super cyclone) in less than 36 hours.
Cyclone Nisarga, June 2020
Nisarga originated in the Arabian Sea and made landfall June 3, 2020 on the Maharashtra coast. It was the strongest tropical cyclone to strike the state in June since 1891
Cyclone Yaas, May 2021
Cyclone Yaas, forming in the Bay of Bengal, devastated several parts of West Bengal May 26 and impacted nearly 10 million people.
Cyclone Tauktae May 2021
Tauktae originated in the Arabian Sea and made landfall along Gujarat’s Saurashtra coast on May 17, leaving a trail of destruction. Four states on the country’s western coast — Maharashtra, Saurashtra and Kutch region in Gujarat and south Rajasthan — were heavily affected
Cyclone Asani, May 2022
Asani had formed May 7 in the Bay of Bengal and dissipated May 12. It had pulled the monsoon winds into the Andaman Sea but did not pull any further. Very heavy rain was reported in Kerala, Andhra Pradesh and Odisha.
Additional Information:
What is a super cyclone?
Super cyclone refers to tropical storm, where wind speeds cross 220 kmph
What is Bomb Cyclone?
Normally, in a storm wind flows from high pressure areas into low pressure areas. But, when the pressure drops in the low pressure areas by ‘24 millibars’ in 24 hours, then it rapidly intensifies the difference between the two air masses strengthening the winds that flow — this process is called ‘bombogenesis’