Tropics
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2008-06-22T08:20:29Z
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[[Image:World map torrid.svg|thumb|350px |right|World map with the tropics highlighted in red]]
The '''tropics''' are the geographic region of the [[Earth]] where the sun passes through the [[zenith]] twice during the solar year (once as the sun appears to go north and once as it appears to go south). At the limits, called the tropics of [[Tropic of Cancer|Cancer]] and [[Tropic of Capricorn|Capricorn]], this occurs once at the relevant [[solstice]].<ref>
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This area is centered on the [[equator]] and limited in [[latitude]] by the [[Tropic of Cancer]] in the northern hemisphere, at approximately 23°26' (23.4°) N latitude, and the [[Tropic of Capricorn]] in the southern hemisphere at 23°26' (23.4°) S latitude. This region is also referred to as the '''tropical zone''' and the '''torrid zone''' (see [[geographical zone]]).
[[Image:Tropical-area-mactan-philippines.jpg|thumb|right|240px|left|A noontime scene from the [[Philippines]] on a day when the [[Sun]] is almost directly overhead.]]
On the other hand, in the [[temperate zone]]s, north of the Tropic of Cancer and south of the Tropic of Capricorn, the sun never reaches the zenith, always passing south (north) of it in the northern (southern) hemisphere.
The word "tropics" comes from [[Greek language|Greek]] ''tropos'' meaning "turn", because the apparent position of the Sun oscillates between the two tropics with a period that defines the average length of a [[year]].
==Tropical seasons and climate==
:''Main article: [[Tropical climate]]
The seasons in the tropics are dominated by the movement of the [[tropical rain belt]] (or [[ITCZ]]), which oscillates from the northern to the southern tropics over the course of the year, thus causing the [[dry season]] and the [[wet season]] in turn.
'''Tropical''' is sometimes used in a general sense for a [[tropical climate]] that is warm to hot and moist year-round, often with the sense of lush vegetation. However, there are places in the tropics that are anything but "tropical" in this sense, with even [[alpine tundra]] and snow-capped peaks, including [[Mauna Kea]], [[Mount Kilimanjaro|Mt. Kilimanjaro]], and the [[Andes]] as far south as the northernmost parts of [[Chile]] and [[Argentina]]. There are also places in the tropics which are [[desert]], with extreme heat, such as the [[Sahara|Sahara Desert]] and [[Australian Outback]].
==Tropical ecosystems==
[[Image:Pajuçara.jpg|thumb|right|Coconut Trees amongst the warm, tropical climate in [[Brazil]].]]
'''Tropical''' plants and animals are those species native to the tropics.
Tropical ecosystems may consist of [[rainforests]], dry deciduous forests, spiny forests, [[desert]] and other habitat types. There are often significant areas of [[biodiversity]], and specie [[endemism]] present particularly in [[rainforest]]s and dry deciduous forests. Some examples of important biodiversity and/or high endicism ecosystems are: [[Costa Rica]]n and [[Nicaragua]]n rainforests, [[Brazil]]ian and [[Venezuela]]n [[Amazon Rainforest]] territories, [[Madagascar dry deciduous forests]], [[Waterberg Biosphere]] of [[South Africa]] and eastern [[Madagascar]] rainforests. Often the soils of tropical forests are low in [[nutrient]] content making them quite vulnerable to [[slash-and-burn]] techniques, which are sometimes an element of [[shifting cultivation]] agricultural systems.
In [[biogeography]], the tropics are divided into paleotropics (Africa, Asia and Australia) and '''[[neotropics]]''' (Central and South America). Together, they are sometimes referred to as the '''pantropics'''. The neotropic region should not be confused with the [[ecozone]] of the same name; in the Old World, this is unambiguous as the paleotropics correspond to the Afrotropical, Indomalayan, and partly the Australasian and Oceanic ecozones.
==See also==
*[[Tropical year]]
*[[Tropic of Cancer]]
*[[Tropic of Capricorn]]
*[[Geographical zone]]
*[[Equator]]
*[[Tropical marine ecosystem]]
==References==
{{reflist}}
[[Category:Tropics| ]]
[[Category:Seasons]]
[[zh-min-nan:Jia̍t-tāi]]
[[bs:Tropi]]
[[br:Trovan]]
[[ca:Tròpic]]
[[cs:Tropický podnebný pás]]
[[cy:Trofannau]]
[[de:Tropen]]
[[es:Zona Intertropical]]
[[eo:Tropikoj]]
[[fr:Tropique]]
[[hr:Tropi]]
[[id:Tropis]]
[[it:Zona torrida]]
[[he:אזור טרופי]]
[[lv:Tropu josla]]
[[lt:Atogrąžos]]
[[hu:Trópusok]]
[[nl:Tropen]]
[[ja:熱帯]]
[[nn:Tropane]]
[[pl:Strefa międzyzwrotnikowa]]
[[pt:Trópico]]
[[ru:Тропики]]
[[sl:Tropi]]
[[fi:Trooppinen vyöhyke]]
[[tl:Tropiko]]
[[vi:Nhiệt đới]]
[[tr:Dönence]]
[[zh:热带]]
[[ta:வெப்பமண்டலம்]]