Schorghofer, Norbert and Aharonson, Oded (2005) Stability and exchange of subsurface ice on Mars. Journal of Geophysical Research E, 110 (E5). E05003. ISSN 0148-0227 http://resolver.caltech.edu/CaltechAUTHORS:20090917-130046514
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We seek a better understanding of the distribution of subsurface ice on Mars, based on the physical processes governing the exchange of vapor between the atmosphere and the subsurface. Ground ice is expected down to ∼49° latitude and lower latitudes at poleward facing slopes. The diffusivity of the regolith also leads to seasonal accumulation of atmospherically derived frost at latitudes poleward of ∼30°. The burial depths and zonally averaged boundaries of subsurface ice observed from neutron emission are consistent with model predictions for ground ice in equilibrium with the observed abundance of atmospheric water vapor. Longitudinal variations in ice distribution are due mainly to thermal inertia and are more pronounced in the observations than in the model. These relations support the notion that the ground ice has at least partially adjusted to the atmospheric water vapor content or is atmospherically derived. Changes in albedo can rapidly alter the equilibrium depth to the ice, creating sources or sinks of atmospheric H_2O while the ground ice is continuously evolving toward a changing equilibrium. At steady state humidity and temperature oscillations, the net flux of vapor is uninhibited by adsorption. The occurrence of temporary frost is characterized by the isosteric enthalpy of adsorption.
|Additional Information:||©2009. American Geophysical Union. Received 19 August 2004; accepted 17 March 2005; published 5 May 2005. It is a pleasure to thank Samar Khatiwala for his work on the thermal model, Bill Feldman and Michael Smith for sharing data in electronic form with us, Mark Simons and Jeroen Tromp for use of their computer clusters, Paul Asimow, David Bish, Troy Hudson, Mike Mellon, and Yuk Yung for insightful discussions, Mimi Gerstell for a careful reading of an earlier version of this manuscript, and Bill Feldman and Bruce Jakosky for helpful reviews. This work was supported, in part, by JPL grant 1250022 and NASA grant NAG5-13326.|
|Subject Keywords:||ground ice; ice stability; Mars|
|Official Citation:||Schorghofer, N., and O. Aharonson (2005), Stability and exchange of subsurface ice on Mars, J. Geophys. Res., 110, E05003, doi:10.1029/2004JE002350.|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||George Porter|
|Deposited On:||02 Oct 2009 23:21|
|Last Modified:||26 Dec 2012 11:23|
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