The Atlantic coastal desert is the westernmost ecoregion in the Sahara Desert of North Africa. It occupies a narrow strip along the Atlantic coast, where the more frequent
fog
Fog is a visible aerosol consisting of tiny water droplets or ice crystals suspended in the air at or near the Earth's surface. Reprint from Fog can be considered a type of low-lying cloud usually resembling stratus, and is heavily influ ...
and haze generated offshore by the cool Canary Current provides sufficient moisture to sustain a variety of
lichen
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.succulents, and shrubs.
Mauritania
Mauritania (; ar, موريتانيا, ', french: Mauritanie; Berber: ''Agawej'' or ''Cengit''; Pulaar: ''Moritani''; Wolof: ''Gànnaar''; Soninke:), officially the Islamic Republic of Mauritania ( ar, الجمهورية الإسلامية ...
. It is bounded on the west by the Atlantic Ocean, on the east by the
North Saharan steppe and woodlands
The North Saharan steppe and woodlands is a desert ecoregion, in the deserts and xeric shrublands biome, that forms the northern edge of the Sahara. It extends east and west across Northern Africa, south of the Mediterranean dry woodlands and s ...
, on the north by the
Mediterranean Acacia-Argania dry woodlands
The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the eas ...
atmospheric stability
Atmospheric instability is a condition where the Earth's atmosphere is generally considered to be unstable and as a result the weather is subjected to a high degree of variability through distance and time. Atmospheric stability is a measure of th ...
in the desert, by cooling air at the base. This increase in atmospheric stability serves to further reduce the amount of rainfall. Therefore, the climate is extremely dry with some 30 mm of annual precipitation in Dakhla, Western Sahara and 40 mm of annual precipitation in Nouadhibou, Mauritania. Several years may pass without any rainfall at all. The climate is very sunny year-round with around 3,200 hours of annual bright sunshine, though far less sunny than in other parts of the desert of North Africa due to
fog
Fog is a visible aerosol consisting of tiny water droplets or ice crystals suspended in the air at or near the Earth's surface. Reprint from Fog can be considered a type of low-lying cloud usually resembling stratus, and is heavily influ ...
and haze. Air in the Atlantic coastal desert is rather moist and the relative humidity is generally over 60% while farther in the interior, it quickly lowers to 30% or less. Temperatures are also much more moderated in this coastal desert and are relatively warm to truly hot in all seasons. Averages daily temperature is 20 °C (68 °F) in Dakhla. Maximum average high temperatures are 27 °C (80.6 °F) while minimum average low temperatures are 13 °C (55.4 °F) in Dakhla.
Ecology
This bioregion is fairly rich in endemic plants but has no endemic fauna. The flora consists of a variety of
lichen
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.succulents and drought-resistant shrubs. The Mediterranean monk seal (''Monachus monachus'') is found here and the broad bays are important over-wintering grounds for large numbers of Palearctic wading birds. Greater flamingoes (''Phoenicopterus roseus'') and many other waterbirds congregate on the wetlands during their migrations. Mammals found here include the Dorcas gazelle (''Gazella dorcas''), golden wolf (''Canis lupusater''), fennec fox (''Fennecus zerda''), Rüppell's fox (''Vulpes rueppelli''), sand cat (''Felis margarita''), honey badger (''Mellivora capensis'') and striped hyena (''Hyaena hyaena'').