December 17, 2013 - Namib Desert
Springtime in Namibia brings a transition from cool, dry weather to hot, humid summer rains. With spring weather comes a subtle blooming, including the creamy yellow acacia and golden-green, heavily scented shepherd's trees. By November the transition to the summer rainy season is well underway. As rains fall, the landscape becomes tinged with green except in the most arid locations – such as extremely arid regions of the Namib desert.
On December 1, 2013, the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Terra satellite flew over Namibia and captured this true-color image. A blush of spring green can be seen across the region, except for a few extremely dry areas which remain tan, cream-colored or red.
The arid Namib Desert, located along the coast of the country, appears orange-red and contains no visible green, except on the semi-arid eastern escarpment. Annual precipitation varies from about 2 mm (0.079 in) in much of the desert to about 200 mm (7.9 in) in the escarpment. In the very arid coastal region, life depends more on moisture brought by frequent fog, rather than rain. Indeed, at the time this image was acquired, a bank of fog sits over the ocean offshore, but overlies the coast at its southernmost reach.
Estimated to have been arid for at least 55 million years, the Namib is said to be the world’s oldest desert. The name means “vast” in the Nama language – an apt term for a sand-strewn expanse which covers 806,000 sq. km (311,000 sq. mi)(including the adjoining Karoo and Kaokoveld desert regions).
Despite the extreme heat and dryness, about 3,5000 species of plants are found in the Namib desert region, about half of which are endemic – and many of which are extraordinary, such as the shrub-like Welwitschia mirabilis, which has only two leaves and is said to live for over 1,000 years. This curious succulent can survive on moisture from fog and dew alone, and is found in a strip of land made up of parts of Namibia and Angola. It is considered a relic of the Jurassic Period and, like its niche environment, has changed very little since that time.