张立凤,张铭. 2001. 斜压切变基流中横波型扰动的特征波动 Ⅱ:谱函数[J]. 气象学报, 59(2):143-156, doi:10.11676/qxxb2001.016
斜压切变基流中横波型扰动的特征波动 Ⅱ:谱函数
CHARACTERISTIC WAVES OF TRANSVERSAL DISTURBANCE AT BAROCLINIC SHEAR FLOW Ⅱ:SPECTRAL FUNCTION
投稿时间:1998-11-06  修订日期:1999-08-31
DOI:10.11676/qxxb2001.016
中文关键词:  斜压切变基流  连续谱  谱函数
英文关键词:Baroclinic shear basic flow  Continuous spectrum  Spectral function
基金项目:国家重点基础性研究发展规划项目(编号G1998040907);国家自然科学基金项目(编号49875008)
作者单位
张立凤 解放军理工大学气象学院, 南京, 211101 
张铭 解放军理工大学气象学院, 南京, 211101 
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全文下载次数: 2009
中文摘要:
      “斜压切变基流中横波型扰动的特征波动:谱点分布”一文中分析了斜压切变基流中横波型扰动的谱点分布,这里又对其谱函数进行了分析讨论。结果表明:当基流在垂直方向存在切变时,重力惯性波与涡旋波的谱函数在垂直方向上均可出现临界层,临界层的高度随频率σ而变化,即重力惯性波与涡旋波都存在连续谱,但涡旋波与重力惯性波连续谱的结构却不同;对天气尺度扰动,两支重力惯性波和1支涡旋波的连续谱不重叠,此时每支波动仅有1个临界层;而对次天气尺度的扰动,重力惯性波与涡旋波的连续谱区会发生重叠,在连续谱的重叠区,重力惯性波仍只有1个临界层,但涡旋波则可以有2个或3个临界层。无论是涡旋波还是重力惯性波其连续谱的波包随时间都是衰减的,但涡旋波波包比重力惯性波波包衰减得慢。
英文摘要:
      The distribution of spectrum point at baroclinic shear basic flow is analy zed in the paperent it led "characteristic waves of tranversal disturbance at baroclinic shear flow Ⅰ:spectrum analysis". The spectral function is studied there. The results show that, when the vertical shear of basic flow is not zero, there is a critical layer in the vertical direction about the spectral function of inertia-gravitational wave and vortex wave. The height of critical layer is changing with frequency. The continuo us spectrum structure of vortex wave is different from that of inertia-gravitational wave.To synoptic scale disturbance, the continuous spectrum of them is not overlapped, and there is only a critical layer to every wave. To subsynoptic scale disturbance, there exists overlap of wave continuo us spectrum. In the overl apped spectrum area, there is still a critical layer to the inertia-gravitational wave, but there are two or three critical layers to vortex wave. Not only vortex wave but also inertia-gravitational waves, the wave ensemble is decaying with time, the decay of vortex waveis slower than inertia-gravitational waves.
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