Sand transport initiation and cessation occurs when the surface shear velocity exceeds a fluid threshold and falls below an impact threshold, respectively. Even when average shear velocity is below fluid threshold, turbulent fluctuations can initiate saltation, leading to turbulence‐driven transport intermittency. We leveraged the dynamic properties of large‐eddy simulation to recover a shear velocity time series due to atmospheric turbulence and recover a probability density function for saltation based on the frequency of events where wind has previously exceeded fluid threshold but not yet dropped below impact threshold. By conditionally sampling, we can quantitatively predict the frequency of intermediate saltation. Results show that a compensated, subthreshold shear velocity exhibits linear dependence upon the actual shear velocity. This compensated shear velocity compares favorably against field data. Model performance under terrestrial and Mars conditions is also shown.

中文翻译：

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基于湍流的亚临界风成盐模型

当表面剪切速度超过流体阈值并降至冲击阈值以下时，发生沙土的运输开始和停止。即使平均剪切速度低于流体阈值，湍流波动也会引发盐分作用，从而导致湍流驱动的运输间歇性。我们利用大涡模拟的动态特性来恢复由于大气湍流引起的剪切速度时间序列，并基于风速已超过流体阈值但尚未降至冲击阈值以下的事件频率恢复盐化的概率密度函数。通过有条件采样，我们可以定量预测中间盐析的频率。结果表明，补偿后的亚阈值剪切速度与实际剪切速度呈线性关系。该补偿的剪切速度与现场数据相比具有优势。还显示了在地面和火星条件下的模型性能。