Orographic Effects on Cold Fronts

锋面穿越地形特征的强度、运动和相关降水受到地形的显著影响。奈特博士将通过两种方法继续研究额叶与地形的相互作用。基于气象学原始方程的二维数值模型将用于计算相互作用中涉及的一系列物理过程。模式冷锋将由演化的非线性斜压波诱发的剪切流形成（理论模拟发展中的中纬度气旋）。在大气湿度存在和不存在的情况下，将模拟不同山脉大小和大气稳定性的影响。在第二种方法下，该模式的模拟将指导冷锋穿越阿巴拉契亚山脉的个案研究的观测分析。将观测到的受山脉影响较大的锋面与不受山脉影响的锋面进行比较。除了阐明相互作用的各个方面之外，案例研究将提供对模型模拟的真实性的部分检查。更好地了解这种相互作用可能会改善山区降水的预测，这对水资源管理是一个关键的帮助。

The strength, movement, and associated precipitation of fronts traversing orographic features can be significantly affected by the terrain. Dr. Knight will continue his studies of frontal inter- action with topography via two approaches. A two-dimensional numerical model based on the primitive equations of meteorology will be used to calculate the suite of physical processes involved in the interaction. The model cold front will be formed by the shear flow induced by an evolving non-linear baroclinic Eady wave (the theoretical analogue of a developing midlatitude cyclone). The effect of varying mountain sizes and atmospheric stabilities will be simulated, in both the presence and absence of atmospheric moisture. Under the second approach, the model's simulations will guide the observational analysis of case studies of cold fronts crossing the Appalachians. Observed fronts that are significantly affected by the mountains will be compared with those that are not. In addition to elucidating aspects of the interaction, the case studies will provide a partial check on the verisimilitude of the model simulations. Better understanding of the interaction may lead to improved predictions of precipitation in mountainous terrain, a key aid in water resource management.