Desert climate
The desert climate or arid climate (in the
There are two variations of a desert climate according to the Köppen climate classification: a hot desert climate (BWh), and a cold desert climate (BWk). To delineate "hot desert climates" from "cold desert climates", a mean annual temperature of 18 °C (64.4 °F) is used as an isotherm so that a location with a BW type climate with the appropriate temperature above this isotherm is classified as "hot arid subtype" (BWh), and a location with the appropriate temperature below the isotherm is classified as "cold arid subtype" (BWk).
Most desert/arid climates receive between 25 and 200 mm (1 and 8 in) of rainfall annually,[2][3] although some of the most consistently hot areas of Central Australia, the Sahel and Guajira Peninsula can be, due to extreme potential evapotranspiration, classed as arid with the annual rainfall as high as 430 millimetres or 17 inches.
Precipitation
Although no part of Earth is known for certain to be rainless, in the
To determine whether a location has an arid climate, the precipitation threshold is determined. The precipitation threshold (in millimetres) involves first multiplying the average annual temperature in °C by 20, then adding 280 if 70% or more of the total precipitation is in the high-sun summer half of the year (April through September in the Northern Hemisphere, or October through March in the Southern), or 140 if 30–70% of the total precipitation is received during the applicable period, or 0 if less than 30% of the total precipitation is so received there. If the area's annual precipitation is less than half the threshold (50%), it is classified as a BW (desert climate), while 50–100% of the threshold results in a semi-arid climate.[4]
Hot desert climates
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Hot desert climates (BWh) are typically found under the
At the time of high sun (summer), scorching, desiccating heat prevails. Hot-month average temperatures are normally between 29 and 35 °C (84 and 95 °F), and midday readings of 43–46 °C (109–115 °F) are common. The world absolute heat records, over 50 °C (122 °F), are generally in the hot deserts, where the heat potential can be the highest on the planet. This includes the record of 56.7 °C (134.1 °F) in
Hot desert climates can be found in the deserts of
Hot deserts are lands of extremes: most of them are among the hottest, the driest and the sunniest places on Earth because of nearly constant high pressure; the nearly permanent removal of low-pressure systems, dynamic fronts and atmospheric disturbances; sinking air motion; dry atmosphere near the surface and aloft; the exacerbated exposure to the sun where solar angles are always high makes this desert inhospitable to most species.
Cold desert climates
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Cold desert climates (BWk) usually feature hot (or warm in a few instances), dry summers, though summers are not typically as hot as hot desert climates. Unlike hot desert climates, cold desert climates tend to feature cold, dry winters. Snow tends to be rare in regions with this climate. The Gobi Desert in northern China and Mongolia is one example of cold desert. Though hot in the summer, it shares the very cold winters of the rest of Inner Asia. Summers in South America's Atacama Desert are mild with only slight temperature variations between seasons. Cold desert climates are typically found at higher altitudes than hot desert climates and are usually drier than hot desert climates.
Cold desert climates are typically located in temperate zones, usually in the leeward
Arctic and Antarctic regions also receive very little precipitation during the year, owing to the exceptionally cold dry air freezing most precipitation; however, both of them are generally classified as having polar climates because they have average summer temperatures below 10 °C (50 °F) even if they have such desert-like features as intermittent streams, hypersaline lakes, and extremely barren terrain in unglaciated areas such as the McMurdo Dry Valleys of Antarctica.[11][12]
See also
- List of deserts
- Dry climate
- Semi-arid
- Desert
References
- .
- ISBN 978-1444300741.
- ^ "What is a Desert Climate?". WorldAtlas. 2017-11-01. Retrieved 2022-04-23.
- .
- ^ Valley, Mailing Address: P. O. Box 579 Death; Us, CA 92328 Phone: 760 786-3200 Contact. "Weather - Death Valley National Park (U.S. National Park Service)". www.nps.gov. Retrieved 2022-04-23.
{{cite web}}
: CS1 maint: numeric names: authors list (link) - ^ "ATLAS CLIMÁTICO IBÉRICO" (PDF). administracion.gob.es/. Instituto de Meteorologia de Portugal. Retrieved May 8, 2017.
- Agencia Estatal de Meteorologia. Retrieved 2024-01-08.
- ^ "Leh". Archived from the original on 2018-02-25. Retrieved 2017-08-16.
- ^ Meteorología, Agencia Estatal de. "Valores climatológicos normales - Agencia Estatal de Meteorología - AEMET. Gobierno de España". www.aemet.es (in Spanish). Retrieved 2024-01-08.
- Agencia Estatal de Meteorologia. Retrieved 2024-01-08.
- ^ "Cold and Polar Deserts". 3 January 2022. Retrieved 2022-03-03.
- ^ "Why are polar regions not considered deserts? – SidmartinBio". www.sidmartinbio.org. Retrieved 2022-04-23.