This paper reports the study of potential water retention mechanisms based on the migration process of water molecules in the lunar regolith. First, we propose innovative definitions for the adsorption barrier coefficient, the collision barrier coefficient, and the total barrier coefficient for water molecule migration in the lunar regolith. Second, we derive an equation that relates the different barrier coefficients. Finally, we develop an equation for the diffusion coefficient of water in the regolith. The results are as follows. The collision barrier coefficient is a function of the soil layer porosity and pore number density and increases with increasing pore number density and decreasing porosity. The adsorption barrier coefficient depends on the soil temperature, adsorption heat, porosity, and pore number density and decreases sharply with increasing temperature. The adsorptive capacity of lunar soil to adsorb water molecules increases with increasing the adsorption barrier coefficient. For soil layers with a lower temperature, adsorption plays a more important role than collision in hindering the migration of H2normalO ${\mathrm{H}}_{2}\mathrm{O}$ molecules in the regolith. The total barrier coefficient increases with decreasing temperature, increasing adsorption heat, decreasing porosity, and increasing pore number density. Our results suggest that the water loss rate is inversely proportional to the total barrier coefficient. The water loss rate decreases with decreasing soil temperature, increasing adsorption heat, decreasing porosity, and increasing pore number density. Namely, water is more likely to be retained in areas where the regolith has a low temperature, large adsorption heat, and both low porosity and large pore number density.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.