Surface chlorophyll a concentration in the global ocean.
Acantharia(Photo : Fabien Lombard)
Satellite observation (GEOS-12) of Hurricane Katrina in August 2005 in the Gulf of Mexico - Source : NASA-NOAA
Colony of salps Salpa fusiformis(Photo : Fabien Lombard)
Average chlorophyll concentration in the surface ocean (from mi-September 1997 to August 2007) from the ocean color sensor SeaWiFS (NASA). Subtropical gyres, in the center of the oceanic basins, are characterized by very low concentrations of chlorophyll a (dark blue) - Source : NASA's Earth Observatory (http:/earthobservatory.nasa.gov)
