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
Explanation
The correct answer is Inter-Tropical Convergence Zone seldom occurs.
Key Points
Reasons for the lack of cyclone formation in the South Atlantic :-
• Sea surface temperatures run a shade cooler than the one ideal for tropical cyclone formation.
• Climatologically high values of vertical wind shear across that basin throughout the year even in summer.
• Vorticity: Lack of pre-existing centres of rotation in the area.
• Absence of tropical waves.
• The Intertropical Convergence Zone (ITZC), which shifts toward the north in northern summer and toward the south in the southern summer, usually stays at or north of the equator.
• The tropospheric vertical wind shear is much too strong and there is typically no inter-tropical convergence zone (ITCZ) over the ocean.
Without an ITCZ to provide synoptic vorticity and convergence resulting in large-scale spin and thunderstorm activity as well as having strong wind shear, it becomes very difficult to generate tropical cyclones.
• ITCZ stays at or near the equator and does not shift southward over the south Atlantic or South Pacific region. Therefore, these regions do not have • the ITCZ over them which is a major cause of the lack of cyclones.
• Lower sea temperatures are also a reason.
