The Inter-Tropical Convergence Zone (ITCZ) is more commonly known as “the Doldrums” and refers to an area along the Equator.
The region essentially forms a belt around the Earth that extends approximately five degrees north and south of the Equator. In this region, the trade winds of the Northern Hemisphere collide with those of the Southern Hemisphere.
Because of the solar heat near the Equator, the warm air is forced upwards, so there is often very little surface wind in the area. This lack of wind can becalm sailing ships for weeks, giving rise to the name “the doldrums.”