Interpretation of high resolution spectra of Mars—III. Calculations of CO abundance and rotational temperature

Abstract

High-resolution spectra for the whole disk of Mars (1) have been reanalyzed to obtain a mean rotational temperature of T rot = 205±7°K (standard deviation) using four distributions for the collision-broadened line half width. A line-by-line calculation using Voigt line profiles has been performed to fit the measured equivalent widths for a range of Martian surface pressures. This fit indicates a carbon monoxide abundance of 47 > w co > 40 cm atm is in the total path for 5 < p s < 6 mb if a constant line width is assumed. If a 25 per-cent error has been made in measuring the equivalent widths, we find for p s = 5 mb that w co = 47 +32 -24 cm atm. Depending upon the distribution of line widths assumed, for line widths which vary throughout the band, we find 57 > w co > 27 cm atm in the total path for 5 < p s < 6 mb.