Calms
Under Doldrums (calms, of French calme "lull", "silence") is the almost windless areas in the area of the equator , especially in the area between the parallel 10 ° the 10th northern latitude , in the so-called. Intertropical convergence zone .
meteorology
In the Kalmen the constantly blowing northeast trade winds of the northern hemisphere and the southeastern trade winds of the southern hemisphere meet. The warming air rises with the formation of large cloud formations up to the height of the tropopause and there diverges in a northeast and southeast direction, creating a mostly windless zone on the ground. These diverging currents are also called antipassates based on the trade winds .
The base area of this convergence of warm air masses is referred to as the " inner tropical convergence zone " due to the calms that occur here, as well as the calms belt . It is a windless low pressure channel .
This very humid and hot region was feared by seafarers, as the sailing ships were often stuck in the doldrums for months, which was fatal for many.
Others
Two other almost windless zones, the horse latitudes, are located around 30–35 degrees of latitude on both hemispheres from the equator. In contrast to the Kalms, however, these are windless high pressure latitudes .