双峰风场中沙丘的形成
Dune initiation in a bimodal wind regime
摘要：
早期的底形通过风、沙输送和表面地形之间复杂的相互作用发展成成熟的沙丘。根据不同的环境和风力条件，驱动沙丘形成的机制，并最终，新生沙丘的形状可能会显着不同。在沙的可用性是丰富的情况下，一个机制，建议触发沙丘生长是线性稳定性理论。到目前为止，这一理论仅在单向风中使用现场证据进行了测试。然而，在世界上的许多地区和其他行星上，风成过程的作用，风的制度往往是双峰或多峰。在这里，我们调查现场证据的原型沙丘形成双峰风下，通过应用线性稳定性分析，发展中的原型沙丘领域。采用最近的理论和实验研究，结合在现场风，泥沙输运，和地形测量在大沙丘国家公园，科罗拉多州，美国在一个月的实地活动，我们使用的线性稳定性理论的发展预测的空间特征（方向和波长）和时间演变（增长率和迁移速度）的原沙丘场。我们发现，理论预测比较以及测量沙丘属性的特点是高分辨率数字高程模型测量重复terres试验激光扫描。我们的研究结果表明，线性稳定性理论是一个定量的预测原型沙丘发展的沙表面双峰风制度。我们的研究结果是显着的，因为它们提供了重要的线性稳定性理论的验证，解释的启动和发展的沙丘走向成熟，在一个复杂的自然环境。
英文摘要：
Early-stage bedforms develop into mature dunes through complex interactions between wind, sand transport and surface topography. Depending on varying environmental and wind conditions, the mechanism driving dune formation and, ultimately, the shape of nascent dunes may differ markedly. In cases where sand availability is plentiful one mechanism suggested for triggering dune growth is linear stability theory. Until now, this theory has only been tested using field evidence in unidirectional winds. However, in many areas of the world and on other planets where aeolian processes act, wind regimes are often bimodal or multimodal. Here, we investigate field evidence of protodune formation under bimodal winds by applying linear stability analysis to a developing protodune field. Employing recent theoretical and experimental research, combined with in-situ wind, sediment transport, and topographic measurements during a month long field campaign at Great Sand Dunes National Park, Colorado, USA, we use a development of the linear stability theory to predict the spatial characteristics (orientation and wavelength) and temporal evolution (growth rate and migration velocity) of a protodune field. We find that the theoretical predictions compare well with measured dunefield attributes as characterized by high-resolution Digital Elevation Models measured using repeat terres trial laser scanning. Our findings suggest that linear stability theory is a quantitative predictor of protodune development on sandy surfaces with a bimodal wind regime. Our findings are significant as they offer critical validation of the linear stability theory for explaining the initiation and development of dunes towards maturity in a complex natural environment.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
