Asymmetry of the Intertropical Convergence Zone 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. The ITCZ would be expected to overlie the geographic equator according to symmetric solar radiation. However, the ITCZ is mostly perennial in the northern hemisphere and in the eastern Pacific and Atlantic Oceans. It was originally explained by the asymmetrical distribution of continents. However, the distribution of land and ocean is severely asymmetric in the Indian Ocean, yet the ITCZ moves back and forth there between the southern and northern hemispheres. Continents surround
Asymmetry of the Intertropical Convergence Zone northern tropicalSST slightly. Vice versa, SST of southern part to the equator is much reduced. Therefore, SST of northern tropical is much higher, and higher than southern tropical, by which increases the CESG. As a result, this positive feedback, which is defined as Wind-Evaporation-SST (WES) will intensify this process. In this way, the WES keeps the ITCZ north of the equator. And the precondition of WES is the asymmetric distribution of SST, and WES also strengthens this process. According to the observation of equatorial upwelling and obvious asymmetry of the ITCZ in the Pacific and Atlantic, it is inferred that