In the South Atlantic and South-Eastern Pacific regions in tropical latitudes, cyclone does not orig

Question

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

Accepted Answer

Tropical cyclones originate and intensify over warm tropical oceans. 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.The most proximate reasons for the lack of activity in the South Atlantic are sea surface temperatures that tend to run a shade cooler than ideal for tropical cyclone formation even in the southern summer, climatologically high values of vertical wind shear across that basin throughout the year, and a lack of pre-existing centers of rotation (vorticity) in that area.Source: NCERT: Fundamental Geography