Mosaicking of global planetary image datasets: 2. Modeling of wind streak thicknesses observed in Thermal Emission Imaging System (THEMIS) daytime and nighttime infrared data

Large-scale, seamless global mosaics, such as the Thermal Emission Imaging System (THEMIS) mosaics, can be used to assess regional- and local-scale relative thermophysical properties, morphology, geology, and other compositional investigations. In this paper we use the THEMIS global mosaics as reconnaissance tools to assess the relative thermophysical properties of materials and target a specific location to examine with a quantitative thermal model. This example highlights the utility of these new data sets through an investigation of the thermophysical properties of wind streaks near the Syrtis Major and Uranius Mons regions. In this study, we quantitatively model depositional wind streak thicknesses near Syrtis Major for a thermophysically homogeneous substrate and a top layer consistent with air fall dust. Using this two layer thermal model, we calculate that wind streaks near Syrtis Major are likely 30-200 mu m thick, depending on the top layer thermal inertia. Given predicted dust deposition and removal rates, we calculate that these wind streaks likely formed in <200 Mars years and represent some of the youngest aeolian features on Mars. The regional wind patterns identified using the THEMIS daytime and nighttime temperature mosaics were related to General Circulation Model data to constrain the season and time-of-day that best match the observed wind directions. The THEMIS global mosaics provide excellent context for integrating data from other instruments and provide the basis for interpreting many physical, mineralogical, and morphologic aspects of Mars.