Inertia‐gravity waves in Antarctica: A case study using simultaneous lidar and radar measurements at McMurdo/Scott Base (77.8°S, 166.7°E)
Inertia‐gravity waves in Antarctica: A case study using simultaneous lidar and radar measurements at McMurdo/Scott Base (77.8°S, 166.7°E)
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DOI：
10.1002/jgrd.50318
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发表时间：
2013-04
期刊：
影响因子：
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通讯作者：
Cao Chen;X. Chu;A. McDonald;S. Vadas;Zhibin Yu;W. Fong;Xian Lu
中科院分区：
文献类型：
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作者：
Cao Chen;X. Chu;A. McDonald;S. Vadas;Zhibin Yu;W. Fong;Xian Lu
本研究首次利用激光雷达和雷达在南极中流层区同时观测到惯性重力波（IGWs）。这也是已知的第一次在同一地点同时观测到两个igw。到达高度（77.8°S, 166.7°E）的Fe玻尔兹曼激光雷达提供高分辨率的温度数据，同位置的中频雷达提供风数据。2011年6月29日，在Fe激光雷达温度和MF雷达风中都观测到相干波结构。根据温度资料确定了两个优势波，其视周期分别为7.7±0.2和5.0±0.1 h，垂直波长分别为22±2和23±2 km。温度和风的同时测量，使得固有的波的性质，可以得到从hodograph分析明确。分析表明，长周期波从北向顺时针方向以θ = 11°±5°的方向向北传播。该波的水平波长λh = 2.2±0.2 × 103 km，固有周期τI = 7.9±0.3 h，固有水平相速（CIh）为80±4 m/s，水平群速（Cgh）和垂直群速（Cgz）分别为48±3 m/s和0.5±0.1 m/s。短周期波τI = 4.5±0.3 h, θ = 100°±4°，λh = 1.1±0.1 × 103 km, CIh = 68±5 m/s。群速度分别为Cgh = 58±5 m/s和Cgz = 1.1±0.1 m/s。因此，两种波都以非常浅的仰角从地平线传播（长周期波和短周期波的φ分别为0.6°±0.1°和φ = 1.1°±0.1°），但来源不同。我们的分析表明，较长周期的IGW很可能起源于不平衡气流区域的平流层。
This study presents the first coincident observation of inertia‐gravity waves (IGWs) by lidar and radar in the Antarctic mesopause region. This is also the first known observation of two simultaneous IGWs at the same location. An Fe Boltzmann lidar at Arrival Heights (77.8°S, 166.7°E) provides high‐resolution temperature data, and a co‐located MF radar provides wind data. On 29 June 2011, coherent wave structures are observed in both the Fe lidar temperature and MF radar winds. Two dominant waves are determined from the temperature data with apparent periods of 7.7 ± 0.2 and 5.0 ± 0.1 h and vertical wavelengths of 22 ± 2 and 23 ± 2 km, respectively. The simultaneous measurements of temperature and wind allow the intrinsic wave properties to be derived from hodograph analyses unambiguously. The analysis shows that the longer‐period wave propagates northward with an azimuth of θ = 11° ± 5° clockwise from north. This wave has a horizontal wavelength of λh = 2.2 ± 0.2 × 103 km and an intrinsic period of τI = 7.9 ± 0.3 h. The intrinsic horizontal phase speed (CIh) for this wave is 80 ± 4 m/s, while the horizontal and vertical group velocities (Cgh and Cgz) are 48 ± 3 m/s and 0.5 ± 0.1 m/s, respectively. The shorter‐period wave has τI = 4.5 ± 0.3 h and θ = 100° ± 4° with λh = 1.1 ± 0.1 × 103 km and CIh = 68 ± 5 m/s. Its group velocities are Cgh = 58 ± 5 m/s and Cgz = 1.1 ± 0.1 m/s. Therefore, both waves propagate with very shallow elevation angles from the horizon (ϕ = 0.6° ± 0.1° and ϕ = 1.1° ± 0.1° for the longer‐ and shorter‐period waves, respectively) but originate from different sources. Our analysis suggests that the longer‐period IGW most likely originates from the stratosphere in a region of unbalanced flow.