Version of Record online: 28 JUN 2008
Volume 44, Issue 5, pages 959–970, October 1997
How to Cite
STOUT, J. E. and ZOBECK, T. M. (1997), Intermittent saltation. Sedimentology, 44: 959–970. doi: 10.1046/j.1365-3091.1997.d01-55.x
- Issue online: 28 JUN 2008
- Version of Record online: 28 JUN 2008
- Manuscript received 10 April 1996; revision accepted 24 December 1996.
During a typical wind erosion event, large variations in wind strength produce temporal variations in saltation activity. The focus of this paper is on a special type of unsteady behaviour - intermittent saltation - a process characterized by bursts of blowing soil interspersed with periods of inactivity. We report here measurements from a field study designed to measure intermittent saltation during three separate 1-h periods. Our measurements show that natural wind erosion events consist of intermittent bursts of blowing soil often occupying a small fraction of the total time. We have managed to describe the level of intermittency by a simple and universal mathematical expression. We find that the level of intermittency is governed by whether typical wind fluctuations span the gap between the mean wind speed and threshold wind speed. We propose a nondimensional number which expresses the ratio of these velocity scales, called the relative wind strength, and find that the level of intermittency can be described by a simple distribution function of the relative wind strength.