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Spacecraft nadir point: 20.2° S, 13.2° E

Photo center point: 19.5° S, 11.5° E

Nadir to Photo Center: West

Spacecraft Altitude: 134 nautical miles (248km)
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(Center Pt,: 19.5S 11.5E)
This photo combines the tools of sunglint and color to tell
oceanographers about the processes off the coast of Namibia.
Internal waves and coccolithophore plankton bloom off the
coast of Nambia, an important highly productive upwelling
area. Upwelling zones of the oceans represent areas of high
biological production and the Space Shuttle shows evidence
that cocolithophore blooms are frequently present. This
little known fact emphasizes the need to develop chlorophyll
distributions accurately in these biologically important
areas. We now know, however, that when high concentrations
of coccolithophores are present there are large errors in
the CZCS derived chlorophyll concentrations. The bloom
appears to have formed directly over where the internal
waves are being refracted around a submerged feature. This
is a view that can only be seen in Space Shuttle
photography. This photograph raises the question of what is
the relationship, is any, between the internal wave field
and the development of the coccolithophore bloom? Taken
with a 100 mm lens (at nadir this captures an area about 90
nm on a side from an altitude of 160nm), on 01 Mar 1990, at
125403 GMT from a 134 nm altitude. The sun azimuth was 295
degrees and elevation was 64 degrees.

These open ocean Internal Waves were seen off the Namibia Coast, Africa (19.5S, 11.5E). The periodic and regularly spaced sets of incoming internal appear to be diffracting against the coastline and recombining to form a network of interference patterns. They seem to coincide with tidal periods about 12 hours apart and wave length (distance from crest to crest) varies between 1.5 and 5.0 miles and the crest lengths stretch beyond the image.