Eur. Phys. J. E (2018) 41: 121
https://doi.org/10.1140/epje/i2018-11730-8

Regular Article

Unsteady aeolian saltation

¹ Northwest Institute of Eco-Environment and Resources, CAS, 730000, Lanzhou, P. R. China
² State Key Laboratory of Earth Surface Processes and Resource Ecology, MOE Engineering Research Center of Desertification and Blown-sand Control, Faculty of Geographical Science, Beijing Normal University, 100875, Beijing, P. R. China

^* e-mail: wangzht@lzu.edu.cn

Received: 17 July 2018
Accepted: 10 September 2018
Published online: 12 October 2018

Abstract

Wind velocity and saltating grain count rate in the natural unsteady aeolian sediment transport are synchronously measured on the gently inclined windward slope of one horn of a large barchan. The obtained time series of these two variables are analyzed, by using the improved complete ensemble empirical mode decomposition and wavelet coherence, to investigate the wind-saltation interactions at different timescales. It is found that the wind-saltation trend relation obeys the traditional low-order polynomial expressions, and saltation mode is roughly proportional to its corresponding wind mode if they are strongly correlated. As a conclusion, it is probable to partly predict instantaneous saltation activities near the surface by the empirical trend and effective modes of wind speed at a given height.