The Relationship of the MOLA Topography of Mars to the Mean Atmospheric Pressure
The Relationship of the MOLA Topography of Mars to the Mean Atmospheric Pressure (Updated 1/4/2015)
Internet Source: http://adsabs.harvard.edu/abs/1999DPS....31.6702S
Smith, D. E.; Zuber, M. T. American Astronomical Society, DPS meeting #31, #67.02
The MOLA topography of Mars is based on a new mean radius of the planet and new equipotential surface for the areoid. The mean atmospheric pressure surface of 6.1 mbars that has been used in the past as a reference level for topography does not apply to the zero level of MOLA elevations. The MOLA mean radius of the planet is 3,389,508 meters and the mean equatorial radius is 3,396,000 meters (Zuber incorrectly gives it as 339,600 meters). The areoid of the zero level of the MOLA altimetry is defined to be the potential surface with the same potential as the mean equatorial radius. The MOLA topography differs from the USGS digital elevation data by approximately 1.6 km, with MOLA higher. The average pressure on the MOLA reference surface for Ls =0 is approximately 5.1 mbars and has been derived from occultation data obtained from the tracking of Viking, Mariner, and MGS spacecraft and interpolated with the aid of the Ames Mars GCM. The new topography and the new occultation data are providing a more reliable relationship between elevation and surface pressure.