HR: 13:55h
AN: NG43A-02    [Abstracts]
TI: Process-scaling Issues of Saltation Dynamics in Wind Tunnel and Field Environments
AU: * FARRELL, E
EM: ejfarrell@geog.tamu.edu
AF: Texas A&M University, 810 O&M Bldg, College Station, Tx 77843, United States
AU: SHERMAN, D
EM: sherman@geog.tamu.edu
AF: Texas A&M University, 810 O&M Bldg, College Station, Tx 77843, United States
AB: This paper examines the scaling up process of aeolian sand transport models from wind tunnels to prototype beach and desert environments. Analyses of enhanced roughness lengths derived from wind velocity profiles and particle trajectory characteristics demonstrate that airflow - surface relationships and subsequent transport models derived from wind tunnel studies should not be applied to natural systems without scaling corrections. Specifically, the scaling constraints of wind tunnels impact aeolian processes in two ways. Firstly, wind tunnel geometry inhibits the development of turbulent coherent flow structures and, thus, particle trajectories are reduced in height and length, and secondly, the saltation enhanced roughness is much smaller in wind tunnels; probably for the same reason. Until these process scaling issues are explicitly addressed in wind blown sand studies, the accuracy of transport models will continue to be poor except by accident.
DE: 4217 Coastal processes
DE: 4430 Complex systems
DE: 4494 Instruments and techniques
DE: 6015 Dust
DE: 6017 Erosion and weathering
SC: Nonlinear Geophysics [NG]
MN: 2007 Fall Meeting