HR: 1340h
AN: P13B-0147    [Abstracts]
TI: Dust Devils on Earth and Mars: Comparison of Field and Laboratory Results for Sediment Flux
AU: * Neakrase, L D
EM: neakrase@asu.edu
AF: Dept. of Geological Sciences, Arizona State University, Box 871404, Tempe, AZ 85283 United States
AU: Greeley, R
EM: greeley@asu.edu
AF: Dept. of Geological Sciences, Arizona State University, Box 871404, Tempe, AZ 85283 United States
AU: Iversen, J D
P13B-0147 AF: Dept. of Aerospace Engineering and Engineering Mechanics, Iowa State University, Ames, IA 50011 United States
AU: Lemmon, M T
P13B-0147 AF: Dept. of Atmospheric Science, Texas A & M University, College Station, TX 77843 United States
AU: Landis, G A
P13B-0147 AF: NASA Glenn Research Center, 21000 Brookpark Rd., Cleveland, OH 44135 United States
AU: Foley, D J
P13B-0147 AF: Dept. of Geological Sciences, Arizona State University, Box 871404, Tempe, AZ 85283 United States
AU: Thompson, S D
P13B-0147 AF: Dept. of Geological Sciences, Univeristy of Nevada, Reno, Reno, NV 89557 United States
AU: Whelley, P L
P13B-0147 AF: Dept. of Geological Sciences, Arizona State University, Box 871404, Tempe, AZ 85283 United States
AU: Eddlemon, E E
P13B-0147 AF: NASA Ames Research Center, Mars Surface Wind Tunnel, Moffett Field, CA 94305 United States
AB: Experiments using the Arizona State University Vortex Generator (ASUVG) investigated the physics of sediment lifted in dust devils. With the use of the Mars Surface Wind Tunnel (MARSWIT) at Ames Research Center, laboratory-sized dust devils were studied under both terrestrial and martian conditions with the ASUVG. Vortex sediment flux was investigated by measuring mass loss as a function of time for different sized vortices and a selection of different types of sediment from dust to sand spanning 2 to 1500 μm. Vortex core pressure drops range from ~0.01 to 1.0% of ambient pressure for both terrestrial and martian conditions. Pressure drops measured previously at the Mars Pathfinder site suggest that martian dust devils also exhibit characteristic drops of ~0.2-1.0% of ambient pressure, which is very similar to previously published data for terrestrial field studies. Recent observations made by the Mars Exploration Rover, Spirit, allowed calculation of dust content and estimations of sediment flux in over 250 dust devils in Gusev Crater on Mars. Sediment fluxes for lab conditions are similar to those for field conditions despite large differences in the sizes of the vortices suggesting that the core pressure drop is controlling the dust devil's ability to lift material. These core pressures also seem to be constrained to maximum drops of ~1.0% of ambient pressure in the natural case potentially limiting the maximum amount of material that can be lifted. Sediment fluxes are expressed as mass per unit area per time (kg/m²/s) taking the size of the vortex into consideration - thus fluxes from smaller dust devils tend to be higher than larger ones due to the limits imposed by the maximum pressure drop of ~1.0% ambient conditions.
DE: 3329 Mesoscale meteorology
DE: 3346 Planetary meteorology (5445, 5739)
DE: 5405 Atmospheres (0343, 1060)
DE: 6225 Mars
SC: Planetary Sciences [P]
MN: Fall Meeting 2005