The thermophysical properties of the Bagnold Dunes, Mars: Ground truthing orbital data

Journal of Geophysical Research: Planets
By: , and 



We compare the thermophysical properties and particle sizes derived from the Mars Science Laboratory rover's Ground Temperature Sensor of the Bagnold dunes, specifically Namib dune, to those derived orbitally from Thermal Emission Imaging System, ultimately linking these measurements to ground truth particle sizes determined from Mars Hand Lens Imager images. In general, we find that all three datasets report consistent particle sizes for the Bagnold dunes (~110–350 μm and are within measurement and model uncertainties), indicating that particle sizes of homogeneous materials inferred from temperature measurements and thermophysical models are reliable. Furthermore, we examine the effects of two physical characteristics that could influence the modeled thermal inertia and particle sizes, including (1) fine‐scale (centimeter to meter scale) ripples and (2) thin layering of indurated/armored materials. To first order, we find that small‐scale ripples and thin (approximately centimeter scale) layers do not significantly affect the determination of bulk thermal inertia from orbital thermal data using a single nighttime temperature. Modeling of a layer of coarse or indurated material reveals that a thin layer (< ~5 mm; similar to what was observed by the Curiosity rover) would not significantly change the observed thermal properties of the surface and would be dominated by the properties of the underlying material. Thermal inertia and particle sizes of relatively homogeneous materials derived from nighttime orbital data should be considered as reliable, as long as there are no significant subpixel anisothermality effects (e.g., lateral mixing of multiple thermophysically distinct materials).

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title The thermophysical properties of the Bagnold Dunes, Mars: Ground truthing orbital data
Series title Journal of Geophysical Research: Planets
DOI 10.1029/2017JE005501
Volume 123
Issue 5
Year Published 2018
Language English
Publisher American Geophysical Union
Contributing office(s) Astrogeology Science Center
Description 15 p.
First page 1307
Last page 1326
Other Geospatial Bagnold Dunes, Mars