Numerical and Observational Studies of Mountain Wave Breaking, PV Banners, and Momentum Transports in Support of the Mesoscale Alpine Program

中尺度高山计划（MAP）是一个国际计划，除其他外，它提供了一个前所未有的机会来量化了解复杂地形附近的气流动力学。首席研究员将参与MAP，并将重点关注以下具体主题：山波/边界层相互作用，不稳定动力学和演化，位涡（PV）旗的产生，动量传输和高空沉积，以及三维地形上的流动间歇性。作为美国参与MAP的一个组成部分，首席研究员将通过一个协调的数值模拟和观测工作计划来解决这些问题。一类数值研究将考察在现实边界层流动和三维地形存在下强波事件的激发和演化。其他模拟将解决复杂地形上的波浪破碎，局部波浪不稳定和耗散引起的PV旗的起源和规模，以及这些过程对动量输送和流动间歇性的影响。观测工作将包括参与MAP现场计划，输入飞机飞行计划和仪器测量模式（取决于模式山波预报、测量目标和可用仪器），以及旨在量化山波激发、破裂、动量传输和间歇性动力学的数据分析工作。这项研究的成功完成将有助于更好地理解复杂地形附近的气流，包括更好地理解和潜在地更好地预测晴空湍流。

The Mesoscale Alpine Programme (MAP) is an international program that, inter alia, offers an unprecedented opportunity to quantify understanding of airflow dynamics in the vicinity of complex terrain. The Principal Investigator will participate in the MAP and will focus on the following specific topics: mountain wave/boundary-layer interactions, instability dynamics and evolution, generation of potential vorticity (PV) banners, momentum transport and deposition aloft, and flow intermittency over three-dimensional terrain.The Principal Investigator will address these topics through a coordinated program of numerical simulations and observational efforts performed as a component of the U. S. participation in MAP. One class of numerical studies will examine the excitation and evolution of strong wave events in the presence of realistic boundary-layer flows and three-dimensional terrain. Other simulations will address wave breaking over complex terrain, the origins and scales of PV banners arising from localized wave instability and dissipation, and the influences of these processes on momentum transports and flow intermittency. Observational efforts will include participation in the MAP field program, inputs to aircraft flight planning and instrument measurement modes (dependent on model mountain wave forecasts, measurement objectives, and available instrumentation), and data analysis efforts aimed at quantifying the dynamics of mountain wave excitation, breaking, momentum transports, and intermittency.Successful completion of this research will lead to a better understanding of airflow near complex terrain including a better understanding and potentially better forecasts of clear air turbulence.