Publication
Reference
Appere T., Schmitt B., Langevin Y., Doute S., Pommerol A., Forget F., Spiga A., Gondet B., Bibring J.-P. (2011). Winter and spring evolution of northern seasonal deposits on Mars from OMEGA on Mars Express. J. Geophys. Res. E, 116, E05001.
Names
  • T. Appere
  • B. Schmitt
  • Y. Langevin
  • S. Doute
  • A. Pommerol
  • F. Forget
  • A. Spiga
  • B. Gondet
  • J.-P. Bibring
Article and keywords
Title
Winter and spring evolution of northern seasonal deposits on Mars from OMEGA on Mars Express
Abstract
The OMEGA visible/near-infrared imaging spectrometer on Mars Express has observed the retreat of the northern seasonal deposits during Martian year 27-28 from the period of maximum extension, close to the northern winter solstice, to the end of the retreat at Ls 95°. We present the temporal and spatial distributions of both CO2 and H2O ices and propose a scenario that describes the winter and spring evolution of the northern seasonal deposits. During winter, the CO2-rich condensates are initially transparent and could be in slab form. A water ice annulus surrounds the sublimating CO2 ice, extending over 6° of latitude at Ls 320°, decreasing to 2° at Ls 350°, and gradually increasing to 4.5° at Ls 50°. This annulus first consists of thin frost as observed by the Viking Lander 2 and is then overlaid by H2O grains trapped in the CO2-rich ice layer and released during CO2 sublimation. By Ls 50°, H2O ice spectrally dominates most of the deposits. In order to hide the still several tens of centimeters thick CO2 ice layer in central areas of the cap we propose the buildup of an optically thick top layer of H2O ice from ice grains previously embedded in the CO2 ice and by cold trapping of water vapor from the sublimating water ice annulus. The CO2 ice signature locally reappears between Ls 50° and 70°. What emerges from our observations is a very active surface-atmosphere water cycle. These data provide additional constraints to the general circulation models simulating the Martian climate.
Keywords
spectroscopy, radiative transfer simulation, bidirectional reflectance spectra, grain size, visible, near-IR, molecular solids, ice, snow, CO2, H2O, mineral, Mars, surface, Mars Express - OMEGA, MGS - TES, Mars Odyssey - THEMIS
Content
spectral data, planetary sciences, spectral data use
Year
2011
Journal
Journal of Geophysical Research - Planets
Volume
116
Number
E5
Pages
E05001
Pages number
27
Document type
article
Publication state
published
Comments
simulated reflectance data
Doi
10.1029/2010JE003762
Identifiers
Publications