Dust flux within dust devils: Preliminary laboratory simulations

作者：Neakrase Lynn D V^*; Greeley Ronald; Iversen James D; Balme M R; Eddlemon Eric E

来源：Geophysical Research Letters, 2006, 33(19): L19S09.

DOI：10.1029/2006GL026810

Laboratory simulations using the Arizona State University Vortex Generator (ASUVG) were run to simulate dust flux in dust devils. These tests used particles 2 mu m in diameter and 2600 kg m(-3) in density, and the results were compared with data from natural dust devils on Earth and Mars. Typically, the cores of dust devils ( regardless of planetary environment) have a pressure drop of similar to 0.2 - 1.5 percent of ambient atmospheric pressure. Core pressure drops in our experiments ranged from similar to 0.01 to 5.00 percent of ambient pressure (10 mbar Mars cases and 1000 mbar for Earth cases). Flux experiments were run at vortex tangential wind velocities of 1 to 42 m s(-1); typically similar to 35 - 50 percent above threshold values for the particles used. Dust flux was determined by time averaged measurements of mass loss for a given vortex size. Dust fluxes of similar to 10(-3) kg m(-2) s(-1) were obtained, similar to estimates for flux for dust devils on Earth and Mars, regardless of core size. Vortex strength appears to be closely related to the strength of the pressure drop in the core (Delta P) and is less determined by size of the vortex. This is critical in scaling the laboratory results to natural dust devils.

• 出版日期2006-9-23