Strong Seasonal and Regional Variations in the Evaporation Rate of Liquid Water on Mars. Issue 10 (20th October 2021) - Temel, Orkun
Abstract: We have investigated the seasonal and regional variations in the evaporation rate of both pure liquid water and liquid brine solutions on the surface of Mars. Our evaporation rate estimates are performed using a novel parameterization method taking into account the effects of concentration difference, between the evaporating liquid water solution and the atmosphere, in addition to the effects of near‐surface winds. The method is based on atmospheric surface‐layer calculations obtained from a global circulation model. We show that near‐surface winds strongly enhance strong seasonal variability in the evaporation rate of liquid solutions on Mars. The evaporation rate of a liquid brine solution can vary seasonally up to a factor of 3 and changes by two orders of magnitude depending on the surface elevation and properties of the terrain. Plain Language Summary: The search for liquid water on modern‐day Mars is one of the main drivers of exploration efforts because of its implications for habitability and value as an in‐situ resource. Recent investigations have shown the plausible surface meteorological conditions for the existence of transient pure and saline water (brine) on the surface of Mars. The possibility of transient pure and briny water on the surface of Mars was suggested based on visual and spectroscopical evidence. A transient liquid water solution, pure or saline, can only exist on the surface of Mars, when the surface temperature and pressure permit its stability against boiling and freezing. The time duration that a liquid water solution can stay on the Martian surface depends on its evaporation rate. Here, we investigated the seasonal and regional variations in the evaporation rate of liquid water. We find that the residence time can vary up to a factor of 3 throughout a full Mars year with a higher geographical dependency that can cause the evaporation rate to vary by two orders of magnitude. Key Points: We use a novel evaporation rate parameterization method with the MarsWRF model Our results show the importance of wind speed variations on the evaporation rate variations We report strong seasonal variations up to a factor of 3 in the evaporation rate of liquid water