Variability of the apparent von Kármán parameter during aeolian saltation

Bailiang Li*, Douglas J. Sherman, Eugene J. Farrell, Jean T. Ellis

*Corresponding author for this work

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36 Citations (Scopus)

Abstract

The variability of the apparent von Krmn parameter κa during aeolian saltation was evaluated in a field experiment at Jericoacoara, Brazil. To test this variability, velocity profiles, Reynolds stress and sand transport data were gathered and analyzed. We used 15 data sets with sand-laden airflow and 2 runs with clear airflow. Results indicated an inverse linear relationship between κa and bulk, gravimetric sand concentration (R2 = 0.746) and sand transport rate (R2 = 0.577). We found values of κa as low as 0.26. This means that using the von Krmn constant, κ (0.40) rather than the variable κa to estimate shear velocity based on the slope of the velocity profile will lead to over estimation of shear velocity, averaging about 20% in this study. This, in turn, produces an over estimation of wind-blown sand transport rates based on models that have terms with shear velocity cubed.

Original languageEnglish
Article numberL15404
JournalGeophysical Research Letters
Volume37
Issue number15
DOIs
Publication statusPublished - 1 Aug 2010
Externally publishedYes

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