Step III:Adding the Color Palette
The next step in the analysis is actually quite simple, but it makes the
data somewhat easier to examine visually.The SeaWiFS chlorophyll color
palette is added to the image.The color palette uses shades of purple and
blue for low chlorophyll concentrations, with green, yellow, orange, and
ultimately red for higher chlorophyll concentrations:
When the color palette is applied to the image, the result looks like this:
Now the variability of chlorophyll concentration is more easily perceived.
However, some of the detail is lost due to the fact that there are more
grayscale hues than color gradations in the palette, i.e., the chlorophyll
concentrations are "grouped" into various colors.
At the mouth of the Rio de la Plata estuary, the orange and red hues of the
palette can be seen.Those colors indicate high chlorophyll concentrations,
but are questionable due to the presence of high concentrations of sediment.
Ocean optical scientists are actively working on algorithms that can produce
reliable chlorophyll concentrations in turbid waters such as these.
The next step is to use the flags and masks that have been added to the data
to look for some particular conditions.
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