Nine-years of mesospheric wind measurements, from two meteor radars at 52°N latitude, were analyzed to study planetary waves (PWs) and tides through estimating their zonal wavenumbers. The analysis reveals that multi-day oscillations are predominantly driven by PW normal modes (NMs), which exhibit distinct seasonal variations and statistical association with Sudden Stratospheric Warming events. Specifically, a prominent 6-day NM emerges in April, followed by dominant 4- and 2-day NMs persisting until June, with subsequent peaks of 2-, 4-, and 6-day NMs extending from July to October. Furthermore, this study presents the first observational verification of the frequencies and zonal wavenumbers of over 10 secondary waves, arising from nonlinear interactions among planetary-scale waves. A notable finding is the prevalence of non-migrating components in the winter 24-hr and summer 8-hr tides, phenomena attributed to the nonlinear interactions. Our findings highlight the complexity of atmospheric nonlinear dynamics in generating diverse planetary-scale periodic oscillations.

中文翻译：

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在北纬 52°和两个经度观测到的中球层风中行星尺度波的非线性相互作用


分析了来自北纬 52°的两台流星雷达进行的 9 年的中间层风测量，以通过估计行星波 （PW） 和潮汐的纬向波数来研究行星波 （PW） 和潮汐。分析表明，多日振荡主要由 PW 正则模态 （NM） 驱动，它表现出明显的季节性变化和与平流层突然变暖事件的统计关联。具体来说，4 月出现了一个突出的 6 天 NM，随后占主导地位的 4 天和 2 天 NM 持续到 6 月，随后 2 天、4 天和 6 天 NM 的峰值从 7 月持续到 10 月。此外，本研究首次对 10 多个次级波的频率和纬向波数进行了观测验证，这些次级波是由行星尺度波之间的非线性相互作用引起的。一个值得注意的发现是在冬季 24 小时和夏季 8 小时潮汐中普遍存在非迁移成分，这种现象归因于非线性相互作用。我们的研究结果强调了大气非线性动力学在产生各种行星尺度周期性振荡方面的复杂性。