HR: 11:35h
AN: P22A-06    [Abstracts]
TI: Wind Erosion Regimes and the Evolution of the Surface of Mars Studied with the NASA Ames Mars General Circulation Model
AU: Armstrong, J
EM: jcarmstrong@weber.edu
AF: Dept. of Physics, Weber State University, Dept. of Physics, Weber State University, Ogden, UT 84403 United States
AU: * Leovy, C
EM: janleovy@yahoo.com
AF: Dept. of Atmospheric Sciences, University of Washington, Box 351640, Seattle, WA 98195-1640 United States
AB: A billion year integration of Mars orbital parameters and the NASA Ames Mars General Circulation Model are combined to investigate the long-term erosional history of the surface of Mars. In agreement with findings of Robert Haberle et al., we find that the distribution of potential surface erosion by wind is robust with respect to orbital parameter variations. Potential erosion is strongest: (1) in storm tracks following the edges of the seasonal polar caps, (2) in regions of low surface elevation, (3) in regions of strong cross-equatorial solstice flows at moderate to high obliquity. It follows that maximum long-term erosion rates occur throughout most of the northern plains, in Acidalia and portions of Amazonis and Utopia, and in the Hellas basin. We also investigate the sensitivity of wind erosion to changes in global mean surface pressure and find, as expected, very high sensitivity. For example, if global mean surface pressure were to increase from the current 6 mb to 40 mb, model potential erosion rates increase by more than one order of magnitude. In this regime, potential erosion rates are sufficiently high that several km of easily eroded fine regolith could be removed in a time span of 100 million years. Possible observational consequences of these results will be discussed.
DE: 5415 Erosion and weathering
DE: 5445 Meteorology (3346)
DE: 3307 Boundary layer processes
DE: 1625 Geomorphology and weathering (1824, 1886)
DE: 0343 Planetary atmospheres (5405, 5407, 5409, 5704, 5705, 5707)
SC: Planetary Sciences [P]
MN: 2004 AGU Fall Meeting