The Living Edens "Namib" -- Earth, Wind, and Fire

The South Atlantic Anticyclone

The South Atlantic Anticyclone has the most influential climatic impact of any high pressure wind circulation system in the Namib region. These anticyclonic (counter-clockwise) winds directly influence the Benguela Current and its associated cold water upwelling system, and are therefore responsible for the maintenance of cool coastal waters, the fog, the high humidity, and the steep climatic gradient from the coast to the inland areas. These winds also impede the rain-bearing clouds from the Indian Ocean from carrying their moisture into the Namib.

These influential southwesterly winds are strongest early in the southern summer (during September and October). During that time, surface water temperatures are lowest, due to increased upwelling of deep, cool ocean waters. Land-sea breezes, caused by differential heating and cooling of the land and sea during the day and night, are also common during this time. This causes quite a contrast between morning and afternoon winds throughout the Namib.

In addition to exerting overall climatic influence over the Namib, the winds dramatically shift the sands found inland in the desert areas.They bring fragments of vegetation, seeds and dead insects -- detritus -- that accumulate on the leeward side of the dunes. This blown organic waste helps ensure the survival of the lizards and other creatures which have learned to survive on the changing surface of the Namib's desert interior.

Blowing dunes with inset of detritus composed of seaweed and
seashells

Coastal Geography

Many caves and pitted surfaces exist in the rocky outcrops along the Namib coast. These openings are formed when salt crystallizes in cracks after water has evaporated. Also, the daily thermal expansion and hydration of salt crusts can cause these crystals to develop a pressure that is 150 times that of a car tire's. Pressures of this intensity can force granite and other geological material to be shattered or moved. The Bogenfels, a huge rock arch on the coast near Luderitz, formed in this way.

The Namib coast also is distinguished by many dry lagoons, which are found mainly between Walvis Bay and the Unjab River. These occur when sedimentation or a sea-level drop causes water to be locked into the lagoon, eventually evaporating to leave a salt pan. Between Luderitz and Walvis Bay, there are a number of distinct lagoons in various stages of evolution. All of them are colonized by various animals and plants seeking sheltered water.