Abstract
An experimental investigation is reported on the photolysis of CO2 for λ > 1740 Å. It is shown that CO is indeed produced when CO2 is exposed to radiation in the wavelength region 1740–2100 Å. Quantum yield measurements have been made for this process and a value of ϕCO = (±25%) has been obtained. It is deduced that this process should occur in the lower atmosphere of Mars, regardless of the details of the mechanism of photolysis. Accordingly, the results of this study tend to support the proposal made by McElroy and Hunten that absorption of solar radiation in the region 1670–2275 Å by CO2 plays a dominant role in the photochemistry of CO2 in the lower atmosphere of Mars.
