Correction for Dust Opacity of Martian Atmospheric Water Vapor Abundances

✍ Scribed by D.M. Hunten; A.L. Sprague; L.R. Doose

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 125 KB
• Volume: 147
• Category: Article
• ISSN: 0019-1035
• DOI: 10.1006/icar.2000.6423

✦ Synopsis

A method is presented to correct for the effects of dust opacity on the derivation of water-vapor abundances from observed spectral absorption lines. We show that the dust opacity can be inferred by use of limb-to-limb measurements of a CO 2 band. Ideally, simultaneous CO 2 and water-vapor measurements at the same location should be obtained; in practice, we make these two measurements sequentially. The effects of the dust opacity are computed by a doubling-adding program that has been applied to many planetary atmospheric problems, one of which is obtaining the phase function and single-scattering albedo of the dust in Mars' atmosphere observed by the cameras on the Mars Pathfinder lander. Sample analyses of data from three nights in March 1999 are shown. For these results there does appear to be a real diurnal variation in the H 2 O abundance.