Airglow imaging of gravity waves: 1. Results from a small network of OH nightglow scanning imagers
Airglow imaging of gravity waves: 1. Results from a small network of OH nightglow scanning imagers
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DOI：
10.1029/2001jd900035
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发表时间：
2001-08
影响因子：
--
通讯作者：
R. Stockwell;R. P. Lowe
中科院分区：
文献类型：
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作者：
R. Stockwell;R. P. Lowe
1998年5月至9月期间，安大略省西南部的一个三站扫描辐射计网络记录了OH夜辉强度变化的图像。每个辐射计每分钟对夜空进行一次16x16点的栅格扫描，当太阳低压角为<；6°时，它会自动开启和关闭。利用联合时频分析技术，包括S变换、局域互谱分析和广义瞬时频率，由OH强度测量得到重力内波的水平相速度、水平波长和频率。分析和观测到在所有三台仪器上看到的重力波集在它们的传播方向上有很强的相关性，在三个地点看到的大多数波在东北方向上都有一个水平波矢量。观测到的水平相速度最常见的参数为45m/S，水平波长为25公里，周期为10min。
Images of the variations of OH nightglow intensities have been recorded by a three-station network of scanning radiometers in southwestern Ontario during the period from May until September 1998. Each radiometer performs a 16 by 16 point raster scan of the night sky every minute, turning itself on and off when the solar depression angle is <6°. The horizontal phase velocity, horizontal wavelength, and frequency of the internal gravity waves are derived from the OH intensity measurements using joint time-frequency analysis techniques, including the S transform, localized cross-spectral analysis, and generalized instantaneous frequency. The ensemble of gravity waves seen in all three instruments are analyzed and observed to have a strong dependence in their propagation direction with the majority of waves seen at each of the three sites having a horizontal wave vector in the northeast direction. The most common parameters observed for horizontal phase speed is 45 m/s, horizontal wavelength is 25 km, and period is 10 min.