Novel analysis of in situ acoustic and optical data collected in a shallow, wave- and current-driven environment enabled determination of (1) particle characteristics that were most affected by near-bed physical forcing over seasonal scales and (2) characteristic shear stress, τ_char, at which the rate of change to particle characteristics was most pronounced. Near-bed forcing and particle responses varied by season. Results indicated that moderate τ_char values of 0.125 Pa drove changes in particle composition during summer. In winter, particle concentration effects were most affected at τ_char of 0.05 Pa, suggesting dominance of fluff layer resuspension. Changes to particle size were most relevant during a biologically productive springtime period, with initiation of particle disaggregation occurring most commonly at τ_char of 0.25 Pa. These results suggest that it may be more important to parameterize τ_char, as opposed to critical shear stress for erosion, for sediment transport models.

中文翻译：

---

在浅层、波浪和电流驱动的环境中，季节性粒子对近床剪应力的响应

对在浅层、波浪和电流驱动的环境中收集的原位声学和光学数据进行新的分析，可以确定 (1) 受季节性尺度上近床物理强迫影响最大的粒子特征和 (2) 特征剪切应力，τ _char，此时粒子特性的变化率最为显着。近床强迫和粒子响应因季节而异。结果表明，0.125 Pa 的适中τ _char值在夏季推动了粒子组成的变化。在冬季，粒子浓度效应在τ _{char处受影响最大}0.05 Pa，表明绒毛层再悬浮占主导地位。在具有生物生产力的春季期间，粒度的变化最为相关，粒子解聚的开始最常见于0.25 Pa 的τ _{char 。这些结果表明参数化}τ _char可能更重要，而不是临界剪切应力侵蚀，用于泥沙输送模型。