TES Dust Cover Index (over MOLA shaded relief)
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The dust cover index is a measure of spectrally-obscuring surface dust on Mars that is independent of thermal inertia and albedo values. It is based on the fact that fine particulate silicates show a pronounced "roll-off" in emissivity in the high wavenumber range of TES spectra (>1200 cm-1) due to a transparency feature in silicates. The global map shows average emissivity from 1350 to 1400 cm-1 where lower emissivity indicates the presence of fine particulate dust on Mars. A full description is given in Ruff and Christensen, 2002 (~1.4 Mb). Please use this citation when using the map. MOLA shaded relief base courtesy of NASA/JPL/Goddard.
The map has been updated from its original form. It is now 16 pixels per degree and excludes spectra in which the water-ice cloud opacity is greater than 0.07 and atmospheric dust opacity is greater than 0.29 to avoid spurious effects in the range of the index due to atmospheric absorption and obscuration. Color, grayscale, and floating point numeric versions are available for download below.
DCI Maps for download:
