Lamb waves in the presence of realistic distributions of temperature and dissipation
Lamb waves in the presence of realistic distributions of temperature and dissipation
复制标题
存在真实温度和耗散分布的兰姆波
DOI：
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发表时间：
1972
期刊：
影响因子：
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通讯作者：
D. Blake
中科院分区：
文献类型：
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作者：
R. Lindzen;D. Blake
兰姆波是无耗散、可压缩、等温大气中的基本自由振荡。它们可以存在于任何时期（小于钟摆日），虽然它们的能量被限制在表面的几个刻度高度内，但它们的振幅随高度呈指数增长。当实际的温度分布或耗散或两者都包括在内时，则对于超过约15分钟的周期，真正的自由振荡不再存在。然而，确实存在类似于兰姆波的振荡，这种振荡对强迫产生高度放大的响应，因此应该主导大气对各种低层大气激励的响应。寿命（或相当于放大率）主要取决于表面摩擦。这种波的振幅随高度增加，直到受到分子扩散和离子阻力的限制。详细的垂直结构，这样的波进行了描述。
Lamb waves are the fundamental free oscillations of a dissipationless, compressible, isothermal atmosphere. They can exist at all periods (less than a pendulum day) and though their energy is confined to within a few scale heights of the surface, their amplitudes increase exponentially with height. When realistic temperature distributions or dissipation or both are included then for periods in excess of about 15 min truly free oscillations no longer exist. However, there do exist oscillations analogous to Lamb waves that yield a highly magnified response to forcing and that should therefore dominate the atmospheric response to various lower atmosphere excitations. The lifetime (or equivalently the magnification) is shown to depend primarily on surface friction. The amplitudes of such waves grow with altitude until limited by a combination of molecular diffusion and ion drag. The detailed vertical structure of such waves is described.