Asymmetry of the Intertropical Convergence Zone it is the equatorial upwelling that prevents the ITCZ being created at the equator. To explain this simply, upwelling brings cold water to the surface, which will cool the above atmosphere and make it stable because of relative high air density due to low temperature. Thus, this area of the equator is different compared to the strong vertical convection and abundant precipitation of the ITCZ. As a result, the SST is latitudinally asymmetric. Asymmetry of the Intertropical Convergence Zone There are a number of explanations of the asymmetry of the Intertropical Convergence Zone (ITCZ), known by sailors as The Doldrums.
Tropical instability waves El Niño conditions are present. Tropical instability waves are not related to tropical waves, which are atmospheric disturbances that propagate westward along the Intertropical Convergence Zone, sometimes giving rise to tropical storms. In both the Atlantic and Pacific oceans, a tongue of cold surface water usually extends westward along the equator from the continental margins. These "cold tongues" consist of water upwelling from the ocean depths, and are surrounded by warmer surface water in both hemispheres. The temperature difference between the cold tongues and the surrounding warm water is largest during the southern hemisphere winter. The Pacific cold tongue is