On April 13, 2014 the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Terra satellite captured a true-color image of what appeared to be a mysterious form dancing in the waters off of Namibia. While the shape is reminiscent of a dancer, or perhaps a pinwheel, the distinct blues and greens, along with the location, confirm this is nothing more mysterious than a phytoplankton bloom.
Blooms are common in the coastal waters off of southwest Africa, where the nutrient-rich currents sweep northward from Antarctica and brush the coastal shelf. Here the strong easterly trade winds blow surface water away from the coast. As the top layer moves westerly, the water rises from the ocean floor and carries additional nutrients upward.
The tiny organisms live in the surface waters off of Namibia year-round. When conditions are right, due to the mixing waters, nutrient enrichment, and adequate sunlight, phytoplankton burst forth in luxurious blooms that can sometimes stretch for hundreds of kilometers. While each organism lives only a short time, such blooms can last for a week or more.