Radiosonde observations of gravity waves in the lower stratosphere over Davis, Antarctica
Radiosonde observations of gravity waves in the lower stratosphere over Davis, Antarctica
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DOI：
10.1002/2014jd022448
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发表时间：
2014-11-16
影响因子：
4.4
通讯作者：
Vincent, R. A.
中科院分区：
文献类型：
--
作者：
Murphy, D. J.;Alexander, S. P.;Vincent, R. A.
利用2001 - 2012年南极戴维斯站（68.6 ° S，78.0 ° E）的探空资料，编制了平流层下部惯性重力波的气候学特征。小波分析从风和温度扰动中提取单波包。小波参数，结合线性重力波理论，允许推导出广泛的波特征。与此分析相关的观测滤波优先选择垂直波长小于2-3公里的惯性重力波。垂直传播的统计显示出强烈的时间和高度的变化。波传播接近水平，并强烈平流的背景风在冬季。值得注意的是，5月初至10月中旬在戴维斯上空的平流层中观察到的波大约有一半向下传播。这一特征分布在观测到的平流层高度范围内。基于向上和向下传播的波之间的相似性和在极地冬季平流层的非线性平衡剩余的垂直结构，它的结论是，由于不平衡流，分布在整个冬季平流层下部的源最好地解释了观测。动能和势能以及动量通量的计算突出了由于不同的分析技术而导致结果变化的可能性。
Radiosonde observations made from Davis station, Antarctica, (68.6 degrees S, 78.0 degrees E) between 2001 and 2012 are used to compile a climatology of lower stratosphere inertial gravity wave characteristics. Wavelet analysis extracts single wave packets from the wind and temperature perturbations. Wavelet parameters, combined with linear gravity wave theory, allow for the derivation of a wide range of wave characteristics. Observational filtering associated with this analysis preferentially selects inertial gravity waves with vertical wavelengths less than 2-3 km. The vertical propagation statistics show strong temporal and height variations. The waves propagate close to the horizontal and are strongly advected by the background wind in the wintertime. Notably, around half of the waves observed in the stratosphere above Davis between early May and mid-October propagate downward. This feature is distributed over the observed stratospheric height range. Based on the similarity between the upward and downward propagating waves and on the vertical structure of the nonlinear balance residual in the polar winter stratosphere, it is concluded that a source due to imbalanced flow that is distributed across the winter lower stratosphere best explains the observations. Calculations of kinetic and potential energies and momentum fluxes highlight the potential for variations in results due to different analysis techniques.