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
Tropical Atlantic Variability Atlantic Nino event, eastern area of Atlantic will appear warm SST anomalies accompanying a relaxation of trade winds. This mechanism, which is known as Bjerknes Feedback, is similar to El Nino/Southern Oscillation( ENSO). “On interannual and longer timescales, no single mode seems to dominate. Instead, several mechanisms are responsible for tropical Atlantic variability. On the equator, both observational and modeling studies indicate that there is a Bjerknes-type air-sea coupled mode arising from the interaction of the equatorial zonal SST gradient, ITCZ convection, zonal wind, and thermocline depth.” Tropical Atlantic Variability The Tropical Atlantic Variability (TAV) is influenced by internal interaction