Doldrums Doldrums The doldrums is a colloquial expression derived from historical maritime usage, which refers to those parts of the Atlantic Ocean and the Pacific Ocean affected by a low-pressure area around the equator where the prevailing winds are calm. The doldrums are also noted for calm periods when the winds disappear altogether, trapping sailing ships for periods of days or weeks. The term appears to have arisen in the eighteenth century, when trans-equator sailing voyages became more common. Since this zone is where two trade winds meet, it is also called the Intertropical Convergence Zone. They roughly lie between latitudes
Tropical cyclogenesis of latitude. The majority of extratropical cyclones tend to restrengthen after completing the transition period. Areas within approximately ten degrees latitude of the equator do not experience a significant Coriolis Force, a vital ingredient in tropical cyclone formation. However, a few tropical cyclones have been observed forming within five degrees of the equator. A combination of wind shear and a lack of tropical disturbances from the Intertropical Convergence Zone (ITCZ) makes it very difficult for the South Atlantic to support tropical activity. Over four tropical cyclones have been observed here such as— a weak tropical storm in 1991 off the