July 3, 2009 - Phytoplankton Bloom off Portugal

Phytoplankton Bloom Near Portugal

A phytoplankton bloom colored the waters off the coast of Portugal blue and green on June 20th, 2009. The MODIS on the Terra satellite captured this image on the same day. Blooms like this occasionally form in this region - this one from 2002 was roughly half the size of Portugal itself!

Phytoplankton are tiny marine organisms that, much like their land-based plant relatives, use sunlight to convert water and carbon dioxide into food. Some species of phytoplankton are coated with scales of calcium (chalk), which can turn the water electric blue. Chlorophyll and other light-capturing pigments in others give the water a deep green hue. Very dark green areas could be caused by extremely high levels of phytoplankton - so much light is being absorbed by chlorophyll that the water appears dark! The proliferation of many different species in various stages of growth and decay can provide many nuances of color.

Image Facts
Satellite: Terra
Date Acquired: 06/20/2009
Resolutions: 1km ( B), 500m ( B), 250m ( B)
Bands Used: 1,4,3
Image Credit: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC