Airglow imaging of gravity waves: 2. Critical layer filtering
Airglow imaging of gravity waves: 2. Critical layer filtering
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DOI：
10.1029/2001jd900036
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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
OH强度的变化的图像已经记录了一个三站网络的扫描辐射计在西南部安大略在1998年5月至9月期间。在所有三个仪器中看到的重力波的集合进行了分析，并观察到它们的传播方向有很强的依赖性，在三个站点中的每个站点看到的大多数波都具有东北方向的水平波矢量。为了理解这些结果，采用了重力波通过大气传输的模型。OH扫描辐射计（OHSCR）观测到的重力波被假定为起源于对流层，具有各向同性频谱，这意味着在所有方向上的平均波幅相等。重力波向上传播，由于“背景风”的影响，它们将经历一个选择过程。利用水平风模式（HWM-93）的水平风，模拟了对流层源重力波的传播，结果与观测结果一致。强纬向风解释了夏季向东传播和冬季向西传播，但纬向风的潮汐分量解释了波传播的北向趋势（以及相应的南向传播波的相对缺乏）。为了进一步验证传输，模型冬季测量OHSCR数据集进行检查，并显示是一致的。
Images of the variations of OH intensities have been recorded by a three-station network of scanning radiometers in southwestern Ontario during the period from May until September 1998. The ensemble of gravity waves seen in all three instruments is 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. In order to understand these results a model of the transmission of gravity waves through the atmosphere was employed. The gravity waves observed by the OH Scanning Radiometers (OHSCRs) are assumed to originate in the troposphere with an isotropic spectrum, meaning that the average wave amplitudes are equal in all directions. The gravity waves propagate upward where they will undergo a selection process owing to the effect of the “background winds.” Using the horizontal winds from the Horizontal Wind Model (HWM-93), the transmission of gravity waves from a tropospheric source is modeled and shown to be consistent with the observations. The strong zonal winds account for the summer eastward and winter westward propagation, but it is the tidal components of the meridional wind that account for the northward tendency of wave propagation (and the corresponding relative absence of southward propagating waves). In order to further validate the transmission, model winter measurements from the OHSCR data set are examined and shown to be consistent.