The Dissipation of Trapped Lee Waves. Part I: Leakage of Inviscid Waves into the Stratosphere
The Dissipation of Trapped Lee Waves. Part I: Leakage of Inviscid Waves into the Stratosphere
复制标题
被困李波的消散。
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
P. Blossey
中科院分区：
文献类型：
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作者：
D. Durran;M. Hills;P. Blossey
摘要通过研究多层大气中单个线性模式的结构，研究了泄漏捕获的山背风波。当最上层的静力稳定性和跨山风速不变时，向下呈指数衰减的模式也随高度呈指数增长。这种随高度增长的原因是，包含相对较大幅度波的信息包沿着光线路径穿过平流层，将它们置于进入平流层更下游的包含相对较低幅度波的信息包的上方。然而，如果捕获的波列是由致密源产生的，所有波都会消失在与通过震源区上方的群速度平行的某条线上。由于泄漏到平流层的下游衰减率强烈依赖于大气结构。在实际大气条件下，下游耗散通常是重要的，这通常包括上升的逆温和强烈的高空对流。
AbstractLeaky trapped mountain lee waves are investigated by examining the structure of individual linear modes in multilayer atmospheres. When the static stability and cross-mountain wind speed are constant in the topmost unbounded layer, modes that decay exponentially downstream also grow exponentially with height. This growth with height occurs because packets containing relatively large-amplitude waves follow ray paths through the stratosphere, placing them above packets entering the stratosphere farther downstream that contain relatively low-amplitude waves. Nevertheless, if the trapped wave train is generated by a compact source, all waves disappear above some line parallel to the group velocity that passes just above the source region.The rate of downstream decay due to leakage into the stratosphere is strongly dependent on the atmospheric structure. Downstream dissipation is often significant under realistic atmospheric conditions, which typically include elevated inversions and strong upper-tropo...