On laboratory simulation and the evaporation rate of water on Mars

Abstract

In order to better understand the stability of water on Mars, and factors likely to affect that stability, we have measured the evaporation rate of water in a CO2 atmosphere at 7 mbar and ∼0°C in a large environmental chamber that minimizes fluctuation in conditions. The average evaporation rate we measured was 1.01 ± 0.19 mm/h. This includes correction for water vapor build-up in the chamber, but not the effect of Mars' lower gravity. When corrections for this are applied, our predicted evaporation rate for water on Mars at 0°C and 7 mbar is 0.73 ± 0.14 mm/h. This is in very good agreement with the value calculated by assuming that evaporation depends on diffusion and buoyancy. The consistency of these results suggests that - at least for these conditions - our approaches to the calculations and the laboratory simulations are reasonable. Copyright 2005 by the American Geophysical Union.