Premium
Surface Roughness Evolution and Implications for the Age of the North Polar Residual Cap of Mars
Author(s) -
Wilcoski A. X.,
Hayne P. O.
Publication year - 2020
Publication title -
journal of geophysical research: planets
Language(s) - English
Resource type - Journals
eISSN - 2169-9100
pISSN - 2169-9097
DOI - 10.1029/2020je006570
Subject(s) - orbiter , mars exploration program , surface roughness , martian , martian surface , polar , thermal , geology , materials science , astrobiology , meteorology , physics , astronomy , composite material
An understanding of the current state of the Martian North Polar Residual Cap (NPRC) is needed to understand the North Polar Layered Deposits (NPLD) as a whole and the recent climate history of Mars. We investigate the evolution of small‐scale (∼10s of m) surface topography on the NPRC using an insolation‐driven ice accumulation/ablation model. We apply a coupled thermal and atmospheric model that calculates ice fluxes at each point on a model surface, allowing the topography to evolve through time. Our thermal model is validated using NPRC surface temperature data gathered by the Mars Climate Sounder (MCS) onboard the Mars Reconnaissance Orbiter (MRO). Roughness developed on the model surface is comparable to that of the NPRC, as we demonstrate using two examples of NPRC surface texture observed using the High‐Resolution Imaging Science Experiment (HiRISE) onboard MRO. We find that insolation‐driven accumulation and/or ablation yields surface roughness with characteristic spatial wavelengths ∼10 − 50 m—comparable to those observed on the NPRC—over timescales of 1–10 ka. The dominant topographic wavelength of a model surface increases as the surface evolves, implying that the wavelengths of topographic features observed on the NPRC may be indicative of the surface ages of those regions.