地形激发斜压波动的数值研究

A NUMERICAL STUDY OF BAROCLINIC DISTURBANCE EXCITED BY MOUNTAIN RIDGE

分别用准地转和半地转两维模式研究了南北向长的山脊对过山斜压气流强迫产生扰动的过程，在扰动发展的初期，地形激发产生扰动占主要地位，扰动尺度也与地形宽度相当，在扰动发展后期，斜压不稳定起主要作用，扰动尺度为不稳定斜压波的尺度。最后把准地转模式和半地转模式的结果作了对比，并讨论了上述结果在实际天气过程中的意义。

Using two-dimensional quasi-geostrophic and semi-geostrophic models, processes of disturbance generation forced by baroclinic current overflowing north-south mountain ridge are studied. It is found that the disturbance excited by topographic effects predominates the early stage of the development with the scale of the disturbance comparable with the width of the topograph, while the later stage witnesses major roles of baroclinic instability with the scale of the disturbance comparable with the unstable baroclinic waves. The ending part of the study focuses on comparison between the two models and discussion of the implication of the results achieved in real atmospheric processes.