A dust storm blew through northeastern Mauritania in late January 2013. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured this natural-color image on January 20. Many of the dust plumes arose in Western Sahara, perhaps fueled by the fine sediments of impermanent rivers and lakes. The dust storm likely picked up more material in northeastern Mauritania, where sand seas cover most of the land surface. Dust-laden winds are some of the most common natural hazards in Mauritania, and less than 1 percent of the land is arable. The Sahara (/səˈhɑːrə/, /səˈhærə/; Arabic: الصحراء الكبرى‎, aṣ-ṣaḥrāʼ al-kubrá, ‘the Greatest Desert’) is a desert located on the African continent. It is the largest hot desert in the world, and the third largest desert overall after Antarctica and the Arctic.[1] Its area of 9,200,000 square kilometres (3,600,000 sq mi) is comparable to the area of China or the United States. The name ‘Sahara’ is derived from a dialectal Arabic word for “desert”, ṣaḥra (صحرا /ˈsˤaħra/).
The desert comprises much of North Africa, excluding the fertile region on the Mediterranean Sea coast, the Atlas Mountains of the Maghreb, and the Nile Valley in Egypt and Sudan. It stretches from the Red Sea in the east and the Mediterranean in the north to the Atlantic Ocean in the west, where the landscape gradually changes from desert to coastal plains. To the south, it is bounded by the Sahel, a belt of semi-arid tropical savanna around the Niger River valley and the Sudan Region of Sub-Saharan Africa. The Sahara can be divided into several regions including: the western Sahara, the central Ahaggar Mountains, the Tibesti Mountains, the Aïr Mountains, the Ténéré desert, and the Libyan Desert.
References
CIA World Factbook. (2013, January 14) Mauritania. Accessed January 22, 2013.

Credit: NASA image courtesy Jeff Schmaltz, LANCE MODIS Rapid Response. Caption by Michon Scott.