Constraining Changes in Surface Dust Thickness on Mars Using Diurnal Surface Temperature Observations From EMIRS

Diurnal surface temperature data collected from the Emirates Mars Infrared Spectrometer have been used to characterize dust redistribution on Mars following a regional dust storm in January 2022. A comparative temporal analysis is conducted pre- and post-dust storm to estimate net changes in surface dust thickness at Syrtis Major, Isidis Planitia, Tyrrhena Terra, Hesperian Planum, and Elysium Planitia. By leveraging data from a numerical thermal model, we relate differences in observed surface temperature to changes in the thickness of the surface dust layer. We describe the methodology for estimating net changes in surface dust thickness, including a description of the thermophysical model employed, provide a sensitivity analysis with respect to local time and surface properties, and discuss the implications of our findings. Surface temperature differences suggest both dust deposition and removal, with some regions experiencing a net removal as high as 340 μm, while other regions experienced net deposition reaching up to 120 μm. Visible-wavelength imagery from the Emirates Exploration Imager, which is more sensitive to changes in surface dust distribution, is incorporated in our analysis to provide additional context. When the area of each region of interest is accounted for, we find that the dust storm had the potential to remove and/or deposit more than 1.51 × 10⁹ and 1.20 × 10⁹ kg, respectively, suggesting that dust reservoirs are capable of transporting vast quantities of dust over short timescales.