Unsteady aeolian saltation
Unsteady aeolian saltation
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DOI：
10.1140/epje/i2018-11730-8
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发表时间：
2018-10
期刊：
影响因子：
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通讯作者：
Zhen-Ting Wang;Chunlai Zhang;Songbo Cen
中科院分区：
文献类型：
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作者：
Zhen-Ting Wang;Chunlai Zhang;Songbo Cen
在大型新月形沙丘一个尖角的迎风坡上，对自然非恒定风沙输运中的风速和跃移颗粒计数率进行了同步测量。利用改进的完全系综经验模态分解和小波相干分析方法，对这两个变量的时间序列进行分析，研究不同时间尺度下风-跃移相互作用。研究发现，风-跃移趋势关系服从传统的低阶多项式表达式，跃移模态与其对应的风模态在强相关时大致成正比。因此，利用给定高度风速的经验趋势和有效模态，可以部分预测近地面瞬时跃移活动。
AbstractWind 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.Graphical abstract