Inertia-Gravity Waves Emitted from Balanced Flow: Observations, Properties, and Consequences
Inertia-Gravity Waves Emitted from Balanced Flow: Observations, Properties, and Consequences
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DOI：
10.1175/2008jas2480.1
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发表时间：
2008-11-01
影响因子：
3.1
通讯作者：
Read, Peter L.
中科院分区：
文献类型：
--
作者：
Williams, Paul D.;Haine, Thomas W. N.;Read, Peter L.
本文介绍了实验室观测的惯性重力波发射的平衡流体流。在旋转双层环实验中，重力惯性波的波长与变形半径非常接近。在Burger数（或转动Froude数）不变的情况下，它们的振幅与Rossby数在0.05-0.14范围内呈线性关系。这种线性尺度挑战了几种动力学理论提出的概念，即平衡运动产生的惯性重力波将呈指数级小。据估计，平衡流泄漏约1%的能量，每个旋转周期的惯性重力波在其产生的峰值。这项研究的结果意味着不可避免的发射的惯性重力波Rossby数类似的大规模的大气和海洋流。结果的外推表明，惯性重力波可能对大气和海洋的能量收支作出重大贡献。特别是，从中尺度涡旋的惯性重力波的排放可能是一个重要的能源在海洋中的深层内部混合。
This paper describes laboratory observations of inertia-gravity waves emitted from balanced fluid flow. In a rotating two-layer annulus experiment, the wavelength of the inertia-gravity waves is very close to the deformation radius. Their amplitude varies linearly with Rossby number in the range 0.05-0.14, at constant Burger number (or rotational Froude number). This linear scaling challenges the notion, suggested by several dynamical theories, that inertia-gravity waves generated by balanced motion will be exponentially small. It is estimated that the balanced flow leaks roughly 1% of its energy each rotation period into the inertia-gravity waves at the peak of their generation.The findings of this study imply an inevitable emission of inertia-gravity waves at Rossby numbers similar to those of the large-scale atmospheric and oceanic flow. Extrapolation of the results suggests that inertia gravity waves might make a significant contribution to the energy budgets of the atmosphere and ocean. In particular, emission of inertia-gravity waves from mesoscale eddies may be an important source of energy for deep interior mixing in the ocean.