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.
Panthalassa two hemispherical belts were separated by the undulating Intertropical Convergence Zone (ITCZ). In northern Panthalassa there was mid-latitude westerlies north of 60°N with easterlies between 60°N and the Equator. Atmospheric circulation north of 30°N is associated with the North Panthalassa High which created Ekman convergence between 15°N and 50°N and Ekman divergence between 5°N and 10°N. A pattern which resulted in northward Sverdrup transport in divergence regions and southward in convergence regions. Western boundary currents resulted in an anti-cyclonic subtropical North Panthalassa gyre at mid-latitudes and a meridional anti-cyclonic circulation centred on 20°N. In tropical northern Panthalassa trade winds created