From UPSC perspective, the following things are important :
Prelims level : Tropical cyclones
Mains level : Frequent cyclonic activities in India
As a very rare occasion during monsoons, Cyclone Gulab has been developed in the Bay of Bengal and later made landfall close in Andhra Pradesh.
Tauktae, Amphan, Fani, Titli, Bulbul, Gaja… And now Gulab. As and when cyclones with intriguing names approach the Indian coasts, a common question comes to our minds: Who names these storms?
This time it is Pakistan, not India, who proposed this name Gulaab!
About Tropical Cyclones
- A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure centre, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rains.
- Depending on its location and strength, a tropical cyclone is referred to by different names, including hurricane, typhoon, tropical storm, cyclonic storm, tropical depression, or simply cyclone.
- A hurricane is a tropical cyclone that occurs in the Atlantic Ocean and the northeastern Pacific Ocean, and a typhoon occurs in the north-western Pacific Ocean.
- In the south Pacific or the Indian Ocean, comparable storms are referred to simply as “tropical cyclones” or “severe cyclonic storms”.
- Three factors —in-sync phase of Madden Julian Oscillation (MJO), warm sea surface temperatures over the Bay of Bengal, and the formation of a low-pressure system.
- The system’s intensification phases between low pressure – well-marked low pressure – depression – deep depression and to finally becoming Cyclone Gulab was rather rapid, even as the system moved closer to the south Odisha – north Andhra Pradesh coast, where it also made landfall.
What makes Gulab special?
- India has a bi-annual cyclone season that occurs between March to May and October to December. But on rare occasions, cyclones do occur in June and September months.
- Cyclones are less common during the June to September monsoon season, as there are limited or almost no favourable conditions for cyclogenesis due to strong monsoon currents.
- This is also the period when the wind shear — that is, the difference between wind speeds at lower and upper atmospheric levels — is very high.
- As a result, clouds do not grow vertically and monsoon depressions often fail to intensify into cyclones.
- So it can be stated that this year, the cyclone season commenced earlier than usual. The last time a cyclone developed in the Bay of Bengal in September was Cyclone Day in 2018.