Abstract

It was shown in a recent study [11] that taking into account the rotation of the Earth’s atmosphere leads to the appearance of a new region of evanescent waves with a continuous frequency spectrum on the diagnostic diagram of acoustic-gravity waves. The region is located below the lower limit of gravity waves, which is equal to \(2\Omega \) for all wavelengths, where \(\Omega \) is the angular frequency of the atmospheric rotation. This result was obtained for high-latitude regions of the atmosphere in which one can be limited to considering only the vertical component of the Earth’s rotation frequency. This paper shows that taking into account both components of the vector \(\vec {\Omega }\) of the atmospheric rotation frequency \(\vec {\Omega }\)—horizontal, \(\Omega \cos \varphi ,\) where \(\varphi \) is the local latitude, and vertical, \(\Omega \sin \varphi \)—the dominant role in the acoustic-gravity wave propagation is played by the vertical component. It is shown that the horizontal component leads to a negligible modification of the boundaries of the regions of acoustic and gravity waves on the diagnostic diagram. It is also shown that the vertical component of the frequency affects most strongly the lower limit of gravity waves, which depends on the latitude of the observation site for all wavelengths and is equal to 2\(\Omega \sin \varphi \).

中文翻译：

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地球大气自转对声重力波谱的影响

摘要

最近的一项研究[11]表明，考虑到地球大气的旋转，会导致在声重力波诊断图上出现一个具有连续频谱的倏逝波新区域。该区域位于重力波的下限以下，对于所有波长都等于\(2\Omega \) ，其中\(\Omega \)是大气旋转的角频率。这一结果是在大气的高纬度地区获得的，在这些地区，人们可以仅限于考虑地球自转频率的垂直分量。本文表明，考虑到大气旋转频率的向量\(\vec {\Omega }\)的两个分量\(\vec {\Omega }\) — 水平方向，\(\Omega \cos \varphi ,\)其中\(\varphi \)是当地纬度，垂直方向，\(\Omega \sin \varphi \) —垂直分量在声-重力波传播中起主导作用。结果表明，水平分量导致诊断图上声波和重力波区域边界的变化可以忽略不计。还表明，频率的垂直分量对重力波的下限影响最大，该下限取决于所有波长的观测地点的纬度，等于 2 \(\Omega \sin \varphi \)。