Brilliant shades of blue and green explode across the Barents Sea in this natural color image taken by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Aqua satellite on August 14, 2011. The color is from a massive phytoplankton bloom made from millions of microscopic organisms. The milky blue color is an indicator that the bloom probably contains coccolithophores, which are plated with white calcium carbonate. Seen through ocean water, a coccolithophore bloom is bright blue. Other shades may be from other species of phytoplankton.
Phytoplankton thrive in cold ocean waters, which tend to be rich in nutrients. The area in this image is immediately north of the Scandinavian peninsula. Blooms spanning hundreds or even thousands of kilometers occur across the North Atlantic and Arctic Oceans every year. Seeing such a wide area without clouds during the bloom is a rare treat, however.