Balme, Matthew; Metzger, Stephen; Towner, Martin; Ringrose, Tim; Greeley, Ronald and Iversen, James
Friction wind speeds in dust devils: a field study.
Geophysical Research Letters, 30(16) p. 1830.
Using in-situ field measurements, we determined surface friction velocities (u*) and aerodynamic roughness heights (z0) at the base of 10 dust devils. z0 values agree closely with previous studies in this region and range from 0.1 to 1.0 cm. The peak u* coincide with the largest wind speed measurements within the dust devil and range from 0.9 to 2.4 ms−1. Surface friction velocities are sufficient to lift all types of windblown material from dust to pebble sized particles. Peak u* values for dust devils appear to be a linear function of the peak wind speed measured at ~2 m height within the dust devil. This provides a simple approximation for estimating surface shear stress for dust devils.
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