Intertropical Convergence Zone Intertropical Convergence Zone The Intertropical Convergence Zone (ITCZ), known by sailors as the doldrums or the calms, is the area encircling Earth near the Equator, where the northeast and southeast trade winds converge. The ITCZ was originally identified from the 1920s to the 1940s as the "Intertropical Front" ("ITF"), but after the recognition in the 1940s and the 1950s of the significance of wind field convergence in tropical weather production, the term "ITCZ" was then applied. When it lies near the Equator, it is called the near-equatorial trough. Where the ITCZ is drawn into and merges with a monsoonal circulation,
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