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Friction wind speeds in dust devils: A field study
Author(s) -
Balme Matthew,
Metzger Stephen,
Towner Martin,
Ringrose Tim,
Greeley Ronald,
Iversen James
Publication year - 2003
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2003gl017493
Subject(s) - wind speed , atmospheric sciences , range (aeronautics) , shear velocity , lift (data mining) , aeolian processes , mineral dust , wind tunnel , surface roughness , geology , environmental science , meteorology , physics , mechanics , materials science , geomorphology , aerosol , turbulence , quantum mechanics , computer science , composite material , data mining
Using in‐situ field measurements, we determined surface friction velocities (u * ) and aerodynamic roughness heights (z 0 ) at the base of 10 dust devils. z 0 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.