Description and Location :
Sahara Desert ( Arabic for The Great Desert )
• The largest hot desert and the third largest desert in the world after Antarctica and the Arctic
• One of the most ‘ unforgiving landscapes ’
• 9,200,000 square kilometers- comparable to the area of the United States .
• The desert covers large sections of Algeria , Chad , Egypt , Libya , Mali , Mauritania , Morocco , Niger , Western Sahara , Sudan and Tunisia .
• Atlantic Ocean- West ; Mediterranean Sea- North ; Red Sea- East ; Niger River Valley- South
• Divided into : Western Sahara ; the central Hoggar Mountains ; the Tibesti Mountains , the Air Mountains , Ténéré desert and the Libyan desert
Functions- Climate :
• One of the worlds most severe climates
• Only has 2 permanent rivers ( Nile and Niger ), and a handful of lakes
• Across the desert , the annual average rainfall equals no more than a few inches or less , much less in many locations . In some areas , no rain at all may fall over several years . Then , several inches may fall in a torrential downpour .
• Natural disturbances : common as the occasional fires or cold weather , and sudden , infrequent & intense rain leading to flooding
• Summer : daytime air temps . can reach over 100 ; the hottest air temp . ever recorded at 136 degrees
Functions- Animals and Plants :
• The Sahara ' s environment requires that the wildlife adapt to hyper-arid conditions , fierce winds , intense heat and wide temperature swings .
• Altogether , the Sahara hosts some 70 species of mammals , 90 species of resident birds , 100 species of reptiles , and numerous species of arthropods ( invertebrates that have jointed limbs , segmented bodies and external skeletons ).
• Harbors a relatively sparse community of wild plants , with the highest concentrations occurring along the northern and southern margins and near the oases and drainages .
• It has imposed adaptations on the plants e . g . near wadis and oases , plants such as date palms , tamarisks and acacia put down long roots to reach life-sustaining water .
• Arid areas : the seeds of flowering plants sprout quickly after a rain , putting down shallow roots , and completing their growing cycle and producing seeds in a matter of days , before the soil dries out