The Martian CO₂; Abundance from Measurements in the 1.05-μ Band

Spectral scans of a portion of the P branch of the 1 .O5-L CO2 band on Mars were obtained during May 1967 with the McMath Solar Telescope at Kitt Peak National Observatory. The equivalent widths of the lines provide an independent measurement of the CO2 abundance; if a pure CO2 atmosphere is assumed, an abundance of 61 ± 14 m atm is derived from the equivalent widths, in agreement with most previous determinations If there are other gases which add to the total Martian surface pressure, the CO2 abundance could be as low as 54 ± 12 m atm