Numerical Modeling of Mesoscale Airflow Over Mountains

主要山脉附近的准确天气预报是一个极其困难的气象问题。大尺度天气系统和山区之间的相互作用往往会产生复杂的中尺度天气模式。由于对控制复杂地形中尺度环流的物理过程的了解不足，预测这些天气模式的发展的努力受到限制。此外，中尺度地形效应还通过“重力波阻力”的作用影响全球环流。全球尺度模式中重力波阻力参数的误差被认为是扩展范围预报误差的一个主要来源。在国家科学基金会以前的支持下，首席调查员研究了山脉上的气流，其直接目标是扩大对地形产生的中尺度扰动的动力学以及这些扰动与大天气尺度气流之间的相互作用的了解。他建议使用理论、数值模型和观测相结合的方法来继续这一研究。最终目标是通过开发更准确的重力波阻力参数来增加基本理解，从而改进天气预报和气候模型。

Accurate weather forecasting in the vicinity of major mountain ranges is an extremely difficult meteorological problem. Interactions between large-scale weather systems and mountainous regions often spawn complex mesoscale weather patterns. Efforts to forecast the development of these weather patterns are limited by deficiencies in understanding of the physical processes governing mesoscale circulations in complex terrain. Additionally, mesoscale orographic effects also influence the global circulation through the action of "gravity wave drag". Errors in the parameterization of gravity-wave drag in global- scale models are believed to be a major source of error in extended range forecasts. Under previous support from the National Science Foundation, the Principal Investigator has studied airflow over mountains with the immediate goal of extending understanding of the dynamics of orographically generated mesoscale disturbances and the interaction between these disturbances and the large synoptic-scale flow. He proposes to use a combination of theory, numerical models and observations to continue this line of research. The ultimate goal is to increase fundamental understanding leading to improved weather forecasts and climate models by developing a more accurate parameterization of gravity- wave drag.//