Arid climate

Earth's dry climate:

Desert climate

Savannah climate

Tundra climate

Ice climate

Climates of the Earth by Humidity:

humid climate

semi-arid climate

arid climate ,
as well as tundra and ice climate here

Arid climate (from Latin aridus : dry, arid), also desert climate , describes dry climates in which the annual rainfall is less than the possible evaporation on a 30-year average . It is the opposite of a humid climate . Extremely arid areas are mostly deserts . The limit to drought is defined by the relationship between precipitation and potential evapotranspiration .

A distinction is made between:

• fully arid climate: precipitation <evaporation applies for ten to twelve months of the year
• semi-arid climate: precipitation <evaporation applies for six to nine months of the year.

A typical characteristic of an arid area is that it has no runoff . Rivers evaporate completely in their course (example: Okavango Delta ) or end in lakes or salt pans without drainage . Examples are the Urmiasee or the Aral Sea . Although most arid areas are in the subtropical desert belt, because the trade winds only reach the so-called horse latitudes , there are arid climates in other regions as well, for example in many high mountains or the polar regions . Another characteristic is the precipitation, with less than 100 mm per year.

Ecophysiological climate classification (according to Lauer and Frankenberg)

The ecophysiological climate classification defines the humidity or aridity according to the duration of the hygric vegetation period in months. Lauer and Frankenberg define the following classes:

• perarid: 0 months
• arid: 1 to 2 months
• subarid: 3 to 4 months

UNEP climate classification

The worldwide distribution of arid areas from 1961 to 1990 according to the UNEP climate index: 51 million km ² (41% of the land surface), habitat for more than 1/3 of humanity. By the end of the 21st century, the area is expected to grow to 58 million km ² .

According to the recommendation of UNEP ( United Nations Environment Program ), the climatic dryness is currently defined by an aridity index AI, which is obtained by forming the quotient with the value of the annual precipitation to the value of the annual potential evapotranspiration . For the climatic zones of the arid regions, this dimensionless index is less than or equal to 0.65.

Definition of the arid climate zones
designation	AI (UNEP aridity index)
hyperarid	<0.05
arid	0.05-0.2
semi-arid	0.2-0.5
subhumid	0.5-0.65

Arid areas

Petrified trees in a dry area near Thiès in Senegal

Areas with extreme drought (selection)
Name (location)	place	mean annual precipitation mm	climate zone
Atacama Desert ( Chile )
	Quillagua	0.1	hyperarid
	Arica	0.5
	Iquique	0.6
	Antofagasta	1.7
	Calama	5.7
	Copiapo	12
McMurdo Dry Valleys ( Antarctica )		3 to 50	hyperarid
Negev desert ( Israel )	Eilat	22.5	hyperarid
Rub al-Chali ( Arabian Peninsula )	Haima ( Oman )	13.7	hyperarid
	(in the sandy areas)	40 to 80
Tarim Basin ( People's Republic of China )	(Average)	116.8
	Lop Nor desert	17.4	hyperarid
	Taklamakan desert	<30
Sahara ( North Africa )	Luxor ( Egypt )	2.65	hyperarid
	Sabha ( Libya )	8.2
	Tamanrasset Algeria	53.6
	Bechar ( Algeria )	87.6	arid
	Tozeur ( Tunisia ) ( Chott el Djerid )	140
Lake Eyre Basin ( Australia )	Eyresee	125	arid
Badain Jaran Desert ( People's Republic of China ) (part of the so-called Gobi Desert )		35 to 115	hyperarid
Great Salt Lake Desert ( United States )	Wendover, Utah (Bonneville Salt Flats)	121	arid
	Great salt lake	≈ 130	semi-arid
Mojave Desert ( United States )	Death Valley ( California / Nevada )	60	arid
Tabernas Desert ( Spain )	Tabernas ( province of Almería )	239	semi-arid

See also

• Maritime climate
• Continental climate

Web links

Commons : Arides Klima  - Collection of images, videos and audio files

• Weather dictionary - Arid climate

Individual evidence

1. ^ ^{A b} NJ Middleton, DSG Thomas: World Atlas of Desertification: United Nations Environmental Program. Arnold, 1992.
2. ↑ ^{a b} Fernando T. Maestre, Roberto Salguero-Gómez, José L. Quero: It is getting hotter in here: determining and projecting the impacts of global environmental change on drylands. In: Philosophical Transactions of the Royal Society of London B: Biological Sciences. 367.1606, 2012, pp. 3062-3075. (on-line)
3. ↑ ^{a b c d e f g h i j k l} S. Feng, Q. Fu: Expansion of global drylands under a warming climate. In: Atmos. Chem. Phys. 13, 2013, pp. 10081-10094. doi: 10.5194 / acp-13-10081-2013 . ( PDF ; 7 MB)
4. ↑ Nick Middleton: 'Dry as a bone'. In: Geographical Magazine. 72.4, 2000, pp. 84-85.
5. ↑ ^{a b c d e} Jonathan DA Clarke: Antiquity of aridity in the Chilean Atacama Desert. In: Geomorphology. 73.1, 2006, pp. 101-114. (on-line)
6. ^ ^{A b} Andrew G. Fountain et al: Snow in the McMurdo Dry Valleys, Antarctica. In: International Journal of Climatology. 30.5, 2010, pp. 633-642. ( PDF ; 369 kB)
7. ^ World Meteorological Organization (WMO): Weather Information for Eilat . Mean total rainfall (1981-2010). (accessed on August 18, 2016)
8. ^ World Meteorological Organization (WMO): Weather Information for Heima . Mean total rainfall (2000–2007). (accessed on August 18, 2016)
9. ↑ Mansour Almazroui include: Recent climate change in the Arabian Peninsula: annual rainfall and temperature analysis of Saudi Arabia for 1978-2009. In: International Journal of Climatology. 32.6, 2012, pp. 953-966. ( online HTML)
10. ↑ Yaning Chen et al .: Regional climate change and its effects on river runoff in the Tarim Basin, China. In: Hydrological Processes. 20.10, 2006, pp. 2207-2216. ( PDF ( Memento from May 1, 2016 in the Internet Archive ); 426 kB)
11. ↑ ^{a b} The information comes from the associated Wikipedia article. (Accessed April 29, 2016)
12. ^ World Meteorological Organization (WMO): Weather Information for Luxor . Mean total rainfall (1971-2000). (accessed on August 18, 2016)
13. ^ World Meteorological Organization (WMO): Weather Information for Sebha . Mean total rainfall (1962–1990). (accessed on August 18, 2016)
14. ^ World Meteorological Organization (WMO): Weather Information for Tamanrasset . Mean total rainfall (1976-2005). (accessed on August 18, 2016)
15. ^ World Meteorological Organization (WMO): Weather Information for Bechar . Mean total rainfall (1976-2005). (accessed on August 18, 2016)
16. ^ Robert G. Bryant: Application of AVHRR to monitoring a climatically sensitive playa. Case study: Chott el Djerid, southern Tunisia. In: Earth Surface Processes and Landforms. 24.4, 1999, pp. 283-302. ( PDF 1 MB)
17. ↑ Anna Habeck-Fardy, Gerald C. Nanson: Environmental character and history of the Lake Eyre Basin, one seventh of the Australian continent. In: Earth Science Reviews. 132, 2014, pp. 39-66. ( PDF ; 1.6 MB)
18. ↑ Ning Ma et al .: Observation of mega-dune evaporation after various rain events in the hinterland of Badain Jaran Desert, China. In: Chinese Science Bulletin. 59.2, 2014, pp. 162-170. ( PDF  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. 1 MB)  
19. ^ Gregory C. Lines: Hydrology and surface morphology of the Bonneville Salt Flats and Pilot Valley playa, Utah. Vol. 2057. Dept. of the Interior, Geological Survey, 1979. ( online PDF 5 MB)
20. ↑ Fawwaz T. Ulaby, Louis F. Dellwig, Thomas Schmugge: Satellite microwave observations of the Utah Great Salt Lake Desert. In: Radio Science. 10.11, 1975, pp. 947-963. ( online PDF 5 MB)
21. ^ NOAA 1981-2010 US Climate Normals
22. ^ A. Solé Benet, Y. Cantón, R. Lázaro, J. Puigdefábregas (2009): Meteorización y erosión en el Sub-Desierto de Tabernas, Almería. Cuadernos de Investigación Geográfica 35 (1): 141-163.