Rippling clouds of phytoplankton bloom off the southwestern side of Norway in the North Sea in this true-color Terra MODIS image acquired on June 5, 2003. The bloom stretches out in three directions at once—off to the northwest, down to the southwest, and in a thinner stream to the southeast—making it look a little like a pinwheel. To the west of the pinwheel is northern Scotland and England, while to the southeast is northwestern Denmark.
Phytoplankton are microscopic organisms that thrive in cold, nutrient-rich waters. They use photosynthesis, like their land-based plant relatives, to convert sunlight into energy. It is the chlorophyll in these organisms that gives them their greenish hue, and this hue, when combined with the deep blue of the water, creates sparkling jewel tones of blues and green. The very bright blue can also be produced by the blue reflection from the water and the reflection from an organism called a coccolithophore, whose chalky, calcium-based covering is bright white. When these organisms concentrate in enough numbers, great clouds of them can be seen from space.
Image courtesy Jeff Schmaltz, MODIS Rapid Response Team, NASA GSFC
