In the South Atlantic and South-Eastern Pacific regions in tropical latitudes, cyclones do not originate. What is the reason?

1. Sea surface temperatures are low
2. Inter-Tropical Convergence Zone seldom occurs
3. Coriolis force is too weak
4. Absence of land in those regions

Explanation

Option (b) is correct

• Tropical cyclones are low-pressure systems that derive their energy from warm ocean waters. However, in the tropical regions of the South Atlantic and the south-eastern Pacific, several factors inhibit their formation. Sea surface temperatures in these regions are generally lower than the threshold required for cyclone development. Additionally, vertical wind shear remains high throughout the year, including during summer, which disrupts the organization of storms. There is also a scarcity of pre-existing disturbances or centers of rotation that could evolve into cyclones.
• Further, the Intertropical Convergence Zone typically stays close to the equator, shifting only slightly north or south with the seasons. In these oceanic regions, it is either weak or largely absent. Since the ITCZ provides essential conditions such as convergence, vorticity, and rising air currents needed for thunderstorm development and large-scale rotation, its absence—combined with strong wind shear—makes the formation of tropical cyclones extremely difficult.

Answer: (b) Inter-Tropical Convergence Zone seldom occurs; Difficulty Level: Medium