Doldrums

Under Doldrums ( calms, from the French calme = slump ) refers to the almost windless areas around the equator, especially in the area between the southern tenth and tenth degree of north latitude, in the so-called Intertropical Convergence Zone. There, take the constantly waving the northeastern trade winds in the Northern Hemisphere and the southeast trade winds of the southern hemisphere each other. The heated air rises up to form a large cloud formations up to the height of the tropopause and diverges in a northeasterly and southeasterly direction, whereby the floor a mostly windless zone is created. These diverging trends is called following the trade winds also anti- trade winds.

The base portion of this convergence of warm air masses is called next innertropischer convergence zone due to the doldrums occurring here as doldrums. It is a windless trough of low pressure.

This very sultry and hot region was feared by sailors, as the sailing ships often for months stuck in the doldrums, what was the undoing of many.

Two other almost windless zones, horse latitudes, are about 30 - 35 degrees of latitude away from the equator in both hemispheres. In contrast to the doldrums however, it is at this order windless high pressure widths.