Properties of inertia-gravity waves in the lowermost stratosphere as observed by the PANSY radar over Syowa Station in the Antarctic
Properties of inertia-gravity waves in the lowermost stratosphere as observed by the PANSY radar over Syowa Station in the Antarctic
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DOI：
10.5194/angeo-34-543-2016
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发表时间：
2015-04
影响因子：
1.9
通讯作者：
M. Mihaliková;Kaoru Sato;M. Tsutsumi;Toru Sato
中科院分区：
文献类型：
--
作者：
M. Mihaliková;Kaoru Sato;M. Tsutsumi;Toru Sato
抽象的。重力惯性波是中层大气动力学的重要组成部分。然而，限制其作用力所需的观测研究仍然不足，特别是在南极地区的偏远地区。一年的观测数据（2013年1月至12月）由PANSY雷达的风组件（垂直分辨率为150 m，时间分辨率为30 min）对平流层最低层短垂直波长（≤ 4 km）、地基周期大于4 h的IGW的特性进行了统计分析（高度范围10至12公里）的速度图方法的帮助下。根据科里奥利参数（f）与固有频率（ω ^）的比值分布的最显著差异，将全年分为夏季和冬季两个季节。冬季和夏季的f scinω ^的平均值分别为0.40和0.45，平均水平波长分别为140和160 km。垂直波长全年平均为1.85公里。对于这两个季节的IGW与向上和向下传播的能量的属性也推导和比较。下传波在夏、冬两季分别占10.7%和18.4%。这种季节性变化超过了先前中纬度研究和基于模型的研究中报告的季节性变化。这与过去在南极地区进行的无线电探空仪数据研究的结果一致。此外，使用所谓的双光束技术，垂直动量通量和IGW的水平扰动速度的方差进行了检查。对流层的天气尺度扰动的水平扰动速度的变化很大的IGW事件的来源，这是在一些情况下显示。
Abstract. Inertia-gravity waves (IGWs) are an important component for the dynamics of the middle atmosphere. However, observational studies needed to constrain their forcing are still insufficient especially in the remote areas of the Antarctic region. One year of observational data (January to December 2013) by the PANSY radar of the wind components (vertical resolution of 150 m and temporal resolution of 30 min) are used to derive statistical analysis of the properties of IGWs with short vertical wavelengths ( ≤ 4 km) and ground-based periods longer than 4 h in the lowermost stratosphere (height range 10 to 12 km) with the help of the hodograph method. The annual change of the IGWs parameters are inspected but no pronounced year cycle is found. The year is divided into two seasons (summer and winter) based on the most prominent difference in the ratio of Coriolis parameter (f) to intrinsic frequency (ω ^ ) distribution. Average of f∕ω ^ for the winter season is 0.40 and for the summer season 0.45 and the average horizontal wavelengths are 140 and 160 km respectively. Vertical wavelengths have an average of 1.85 km through the year. For both seasons the properties of IGWs with upward and downward propagation of the energy are also derived and compared. The percentage of downward propagating waves is 10.7 and 18.4 % in the summer and winter season respectively. This seasonal change is more than the one previously reported in the studies from mid-latitudes and model-based studies. It is in agreement with the findings of past radiosonde data-based studies from the Antarctic region. In addition, using the so-called dual-beam technique, vertical momentum flux and the variance of the horizontal perturbation velocities of IGWs are examined. Tropospheric disturbances of synoptic-scale are suggested as a source of episodes of IGWs with large variance of horizontal perturbation velocities, and this is shown in a number of cases.