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 the geometries of the continents. According to observations, the Sea Surface Temperature (SST) of ITCZ in the Northern Hemisphere is higher than the same latitude in the Southern Hemisphere. The asymmetry of ITCZ is triggered by the asymmetric SST distribution, which has been verified by General Circulation Model (GCM). What is more, because the Cross Equator SST Gradient (CESG) is southward, the cross equator northward wind, which decelerates trade winds north of the equator and accelerates those south of the equator due to Coriolis force, is originated. Thus the evaporation of the northern tropics is weakened, thereby cooling down the