February 2, 2011 - Phytoplankton Bloom off the coast of Chile

Phytoplankton Bloom off the coast of Chile

Swirls of greens and blue mixed in the cold, ink-blue waters along the coast of Chile and extended far into the South Pacific Ocean on January 25, 2011. The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Aqua satellite acquired this true-color image that same day. In a swath running north to south along the center of the image, the view of the intense colors are blurred by sunglint, the mirror-like reflection of Sun off the surface of the water.

The extensive curling and brilliant swirls of color are caused by a bloom of phytoplankton – tiny marine organisms which contain chlorophyll and other pigments. The color of the bloom depends both on the species of the phytoplankton involved and the depth at which the bloom occurs. Intense algae blooms usually occur when nutrient-rich cold water upwells towards the ocean surface, carrying nutrients from ocean depths upward into light-rich region. With the combination of rich nutrients and plentiful light, phytoplankton thrive.

The Humboldt Current is the cold, low salinity current that stirs the water off of Chile’s coast, nourishing a rich variety of marine species. This current flows from the southern tip of Chile to the northern tip of Peru, and is one of the major upwelling systems of the world. Off the coast of Peru, the upwelling occurs year round, but, due to the effect of the displacement of the subtropical center of high pressure during the summer, upwelling occurs off the Chilean coast only during spring and summer.

Image Facts
Satellite: Aqua
Date Acquired: 1/25//2010
Resolutions: 1km ( B), 500m ( B), 250m ( B)
Bands Used: 1,4,3
Image Credit: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC