November 22, 2009 - Spring Bloom in the South Atlantic Ocean

Spring Bloom in the South Atlantic Ocean

The South Atlantic Ocean off the coast of Argentina was streaked with beautiful green and blue color on November 15, 2009. This image was captured by the MODIS on the Terra satellite on the same day. The color is due to a phytoplankton bloom.

Phytoplankton are plant-like organisms that live in the surface waters of the ocean. They grow best in cool waters, where the temperature difference between the surface and the oceanís depths is small enough to allow nutrient-rich deep water to mix with surface waters. A few different factors may be contributing to the bloom seen in this image. First, a cold current sweeps north from Antarctica along the coast of Argentina. Second, winds often drive upwelling along the continental shelf. Both the current and upwelling chill the South Atlantic in this region, making it possible for nutrient-rich deep water to reach the surface.

With access to nutrients and increasing springtime sunlight, phytoplankton thrive, developing into large blooms. There are probably many different kinds of phytoplankton growing in the waters off Argentina, accounting for the wide variations in color. Phytoplankton are the base of the marine food chain. Regular blooms such as this one make coastal Argentina a rich fishing ground.

Image Facts
Satellite: Terra
Date Acquired: 11/15/2009
Resolutions: 1km ( B), 500m ( B), 250m ( B)
Bands Used: 1,4,3
Image Credit: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC