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,
Denver Convergence Vorticity Zone the role of the DCVZ in tornado outbreaks across the Denver area. Using climatic data from the 1980s, one researcher has suggested that the presence of a strong June DCVZ has been associated with a 70% chance of zone-area tornado formation. Denver Convergence Vorticity Zone The Denver Convergence Vorticity Zone (DCVZ) is an orographically-induced atmospheric phenomenon characterized by convergent winds east of the Denver metropolitan area, typically 50 to 100 km in length and oriented in a north-south direction. This meteorological feature was subject to academic scrutiny following a large outbreak of Denver-area tornadoes in 1981 and has been used