In the South Atlantic and South-Eastern Pacific regions in tropical latitudes, cyclone does not originate. What is the reason?
[UPSC Civil Services Exam – 2015 Prelims]
(a) Sea surface temperatures are low
(b) Inter-Tropical Convergence Zone seldom occurs
(c) Coriolis force is too weak
(d) Absence of land in those regions
The South Atlantic is not conducive to the formation of cyclones due to several reasons:
- The sea surface temperatures are slightly cooler than the optimum temperature required for tropical cyclone formation.
- The area experiences high vertical wind shear throughout the year, which further inhibits cyclone formation.
- Additionally, there is a lack of pre-existing centers of rotation and tropical waves in the region, which also contributes to the absence of cyclones.
- The Intertropical Convergence Zone (ITCZ) remains at or north of the equator, resulting in a lack of synoptic vorticity and convergence necessary for cyclone formation.
- Furthermore, the strong wind shear and absence of ITCZ over the ocean make it challenging to generate tropical cyclones.
- The South Atlantic and South Pacific regions also lack the ITCZ over them, which is a crucial factor contributing to the lack of cyclones.
- Finally, the lower sea temperatures in the region also play a role in the absence of cyclone formation.
Therefore, option (b) is the correct answer.