Surface Oxidation: A Major Sink for Water on Mars

Abstract
Surface oxidation irreversibly removes both oxygen and hydrogen from the martian atmosphere at a rate of 108 to 1011 per square centimeter per second. This rate corresponds to a net loss of 1025 to 1028 per square centimeter (102 to 105 grams per square centimeter) of H2O, if it is assumed that the loss rate is uniform over geologic time. Heretofore, exospheric escape was considered to be the principal irreversible sink for H2O, but the loss rate was estimated to be only 108 per square centimeter per second. It is possible that surface oxidation may have had a minor effect on the supply of H2O in the regolith and polar caps.