Mountain-Wave Evolution and Orographic Precipitation

山脉形成了阻挡气流的天然屏障。 当一般的风，特别是风暴，接近山脉时，山波在屏障的上方和下游发展。 与此同时，低空气流可能会被阻塞，并在山脉周边改道。 这些流动的尺度往往太小，无法被全球天气和气候模型准确捕捉，但会对必须参数化的大尺度流动产生阻力。 这项研究包括两名研究生的培训和专业发展，其中包括一名代表性不足的少数民族。 研究结果将通过期刊文章和会议演示分享，包括由美国气象学会（AMS）山区气象委员会组织的网络研讨会。 这项研究的结果也将有利于水资源管理人员，水文学家和那些研究我们的气候现状和未来潜在的中纬度风暴的变化。这项研究试图把参数化更坚实的理论基础。 将通过高分辨率数值模拟分析来研究对地形阻力的大规模反应。 山区的强降水在很大程度上是由大规模天气系统的通过驱动的。 这些天气系统与理想化山脉的相互作用的原型理论研究以前没有进行，由于模拟大规模和小规模的流动的复杂性。 这项研究建立在以前的研究中的多尺度相互作用的干空气流的潮湿流的结果，中纬度气旋和更本地化的上升地形强迫成强烈的上升气流和增强降水的组合。

Mountains form natural barriers to wind flow. As winds in general, and storms in particular, approach mountain ranges, mountain waves develop above and downstream of the barrier. At the same time, low-level flow may become blocked and diverted around the periphery of the mountains. These flows are often too small in scale to be accurately captured by global weather and climate models, but produce drag on the large-scale flow that must be parameterized. This research includes the training and professional development of two graduate students, including one under-represented minority. Results will be shared through journal articles and conference presentations, including webinars organized by the Mountain Meteorology Committee of the American Meteorological Society (AMS). The results of this research will also benefit water resource managers, hydrologists and those studying the current state of our climate and potential future shifts in mid-latitude storms.This study attempts to place parameterization on a firmer theoretical foundation. The large-scale responses to orographic drag will be studied through the analysis of high-resolution numerical simulations. Heavy precipitation over mountains is largely driven by the passage of large-scale weather systems. Prototypical theoretical studies of the interactions of these weather systems with idealized mountain ranges have not previously been undertaken due to the complexity of modeling large- and small-scale flows. This research builds on prior studies of multi-scale interactions in dry air flow by the inclusion of moist flow as a result of the combination of mid-latitude cyclones and more localized ascent forced by topography into vigorous updrafts and enhanced precipitation.