Thermophysical Properties of the North Polar Residual Cap using Mars Global Surveyor Thermal Emission Spectrometer

J. Bapst, S. Byrne, J. L. Bandfield, P. O. Hayne

Research output: Contribution to journalArticle

1 Scopus citations

Abstract

Using derived temperatures from thermal-infrared instruments aboard orbiting spacecraft, we constrain the thermophysical properties, in the upper few meters, of the north polar residual cap of Mars. In line with previous authors we test a homogeneous thermal model (i.e., depth-independent thermal properties), simulating water ice of varying porosity against observed temperatures. We find that high thermal inertia (>1,000 J m−2 K−1 s 1/2 or <40% porosity) provides the best fit for most of the residual cap. Additionally, we test the observed data against models with depth-dependent thermal properties. Models tested converge on similar solutions: we find extensive regions of low surface thermal inertia consistent with a porous layer at the surface (>40% porosity) that densifies with depth into a zero-porosity ice layer at shallow depths (<0.5 m). We interpret this as evidence of recent water ice accumulation. Our results along the edge of the residual cap imply that denser (<40% porosity) ice is present at the surface and coincides with lower albedo. These results suggest that older ice is undergoing exhumation along much of the residual cap margin. The results support recent water ice accumulation having occurred over specific regions, while ablation dominates in others.

Original languageEnglish (US)
Pages (from-to)1315-1330
Number of pages16
JournalJournal of Geophysical Research: Planets
Volume124
Issue number5
DOIs
StatePublished - May 2019

Keywords

  • Mars
  • accumulation
  • climate
  • ice
  • polar
  • thermophysics

ASJC Scopus subject areas

  • Geophysics
  • Forestry
  • Oceanography
  • Aquatic Science
  • Ecology
  • Water Science and Technology
  • Soil Science
  • Geochemistry and Petrology
  • Earth-Surface Processes
  • Atmospheric Science
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science
  • Palaeontology

Fingerprint Dive into the research topics of 'Thermophysical Properties of the North Polar Residual Cap using Mars Global Surveyor Thermal Emission Spectrometer'. Together they form a unique fingerprint.

  • Cite this