Wintertime column modeling in Jezero crater, Mars: Period of near-fog and a dust event

Abstract

The diurnal water cycle was studied at a Jezero crater base site using M2020 observations and adsorptive column modeling in a cool midwinter period just before a dust peak and at the peak. During low-dust sols 566–571 the observed air relative humidity (RH) at 1.45 m height was high, 40–90% near dawn. For the typical nocturnal wind speed of 2 m/s at 1.45 m and column water of 9.7 μm, the model's diurnal air temperatures and RH were within observations. For weaker winds model-RH increased as in some of the observed sols. In a nearly calm experiment fog formed from 1.45 m upward. Ground frost appeared independently of wind, but only if adsorption was disabled. The dust peak at around sol 577 was also well simulated with the same wind and absolute humidity as before the event, but relative humidities dropped dramatically due to the dust-enhanced higher nocturnal temperatures.