Editing Intertropical Convergence Zone (section)

==Effects on weather==
[[Image:ITCZ january-july.png|thumb|right|The ITCZ moves farther away from the equator during the Northern summer than the Southern one due to the North-heavy arrangement of the continents.]]

Variation in the location of the intertropical convergence zone drastically affects rainfall in many equatorial nations, resulting in the wet and dry seasons of the tropics rather than the cold and warm seasons of higher latitudes.  Longer term changes in the intertropical convergence zone can result in severe [[drought]]s or flooding in nearby areas.

In some cases, the ITCZ may become narrow, especially when it moves away from the equator; the ITCZ can then be interpreted as a [[Weather front|front]] along the leading edge of the equatorial air.<ref>Djurić, D: ''Weather Analysis''. Prentice Hall, 1994. {{ISBN|0-13-501149-3}}.</ref>  There appears to be a 15 to 25-day cycle in thunderstorm activity along the ITCZ, which is roughly half the wavelength of the [[Madden–Julian oscillation]] (MJO).<ref>Patrick A. Harr. [https://web.archive.org/web/20071129132952/http://www.onr.navy.mil/sci_tech/32/reports/docs/05/mmharr.pdf Tropical Cyclone Formation/Structure/Motion Studies.] [[Office of Naval Research]] Retrieved on 2006-11-26. </ref>

Within the ITCZ the average winds are slight, unlike the zones north and south of the equator where the trade winds feed. As trans-equator sea voyages became more common, sailors in the eighteenth century named this belt of calm ''the doldrums'' because of the calm, stagnant, or inactive winds.


[[File:The doldrums, without winds.jpg|thumb|The "doldrums" is a popular nautical term that refers to the belt around the Earth near the equator where sailing ships sometimes get stuck on windless waters.]]