Difference between revisions of "AY Honors/Weather - Advanced/Answer Key"
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The '''Intertropical Convergence Zone''' '''(ITCZ)''', also known as the '''Intertropical Front''' or the '''Equatorial Convergence Zone''', is a belt of [[low pressure area|low pressure]] girdling [[Earth]] at the [[equator]]. It is formed by the vertical ascent of warm, moist air from the latitudes above and below the equator. | The '''Intertropical Convergence Zone''' '''(ITCZ)''', also known as the '''Intertropical Front''' or the '''Equatorial Convergence Zone''', is a belt of [[low pressure area|low pressure]] girdling [[Earth]] at the [[equator]]. It is formed by the vertical ascent of warm, moist air from the latitudes above and below the equator. | ||
| − | The | + | The air is drawn into the intertropical convergence zone by the action of the [[Hadley cell]], a [[scale (spatial)|macroscale]] [[earth's atmosphere|atmospheric]] feature which is part of the Earth's heat and moisture distribution system. It is transported aloft by the [[convection|convective]] activity of [[thunderstorm]]s; regions in the intertropical convergence zone receive [[precipitation (meteorology)|precipitation]] more than 200 days in a year. |
The location of the intertropical convergence zone varies over time. Over land, it moves back and forth across the equator following the sun's [[zenith]] point. Over the oceans, where the convergence zone is better defined, the seasonal cycle is more subtle, as the convection is constrained by the distribution of ocean temperatures. | The location of the intertropical convergence zone varies over time. Over land, it moves back and forth across the equator following the sun's [[zenith]] point. Over the oceans, where the convergence zone is better defined, the seasonal cycle is more subtle, as the convection is constrained by the distribution of ocean temperatures. | ||
Revision as of 04:43, 8 October 2006
The Intertropical Convergence Zone (ITCZ), also known as the Intertropical Front or the Equatorial Convergence Zone, is a belt of low pressure girdling Earth at the equator. It is formed by the vertical ascent of warm, moist air from the latitudes above and below the equator.
The air is drawn into the intertropical convergence zone by the action of the Hadley cell, a macroscale atmospheric feature which is part of the Earth's heat and moisture distribution system. It is transported aloft by the convective activity of thunderstorms; regions in the intertropical convergence zone receive precipitation more than 200 days in a year.
The location of the intertropical convergence zone varies over time. Over land, it moves back and forth across the equator following the sun's zenith point. Over the oceans, where the convergence zone is better defined, the seasonal cycle is more subtle, as the convection is constrained by the distribution of ocean temperatures.
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 droughts or flooding in nearby areas.
Within the ITCZ the average winds are slight, unlike the zones north and south of the equator where the trade winds feed in. Early sailors named this belt of calm the doldrums because of the low spirits they found themselves in after days of no wind. To find oneself becalmed in this region in a hot and muggy climate could mean death in an era when wind was the only major motive force.
Sometimes, a double ITCZ forms, with one located north and another south of the equator. When this occurs, a narrow ridge of high pressure forms between the two convergence zones, one of which is usually stronger than the other.
See also
References
de:Innertropische Konvergenzzone es:Zona de convergencia intertropical fr:Zone de convergence intertropicale nl:Doldrum no:Den intertropiske konvergenssonen nn:Den intertropiske konvergenssona pl:Tropikalna strefa konwergencji simple:Doldrums fi:Pasaatituulten kohtaamisvyöhyke sv:Intertropiska konvergenszonen
