Atlantic Chlorphyll Concentrations

May 22, 2002


Referred by: NASA/GSFC, ORBIMAGE, SeaWiFS Project
Summary authors & editors: Jim Foster; SeaWiFS Project

The two SeaWiFS satellite images of coastal, eastern North America shown above (taken on May 11, 2002) are derived from the same data but are processed in different ways. One image shows a quasi-true-color view , and the other image is a pseudo-color representation of sea surface chlorophyll concentrations overlaid on the quasi-true-color image. Wait a couple of seconds and the 2 images should flash back and forth.

The chlorophyll image illustrates the complexity of microscopic marine life in the eastern North Atlantic Ocean. Thriving phytoplankton populations, found in the cool waters off Georges Bank (east of Cape Cod) and in the Gulf of Maine (near top of image), exhibit high chlorophyll concentrations. These concentrations decrease rapidly to the south, near the northern boundary of the meandering Gulf Stream.

The chlorophyll concentrations aren't able to tell us how different species of phytoplankton are distributed. However, by looking at the quasi-true-color image and noting how the colors of the various blooms differ from each other, you can get an idea of the phytoplankton distribution. The color differences are associated with differences in species composition - variations in pigments and light scattering characteristics are detected by the SeaWiFS sensor.

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