The interaction between infrasonic waves and gravity wave perturbations: Application to observations using UTTR Rocket Motor Fuel Elimination Events
The interaction between infrasonic waves and gravity wave perturbations: Application to observations using UTTR Rocket Motor Fuel Elimination Events
复制标题
次声波和重力波扰动之间的相互作用：使用 UTTR 火箭发动机燃料消除事件进行观测的应用
DOI：
10.1002/2015jd024527
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
R. Waxler
中科院分区：
文献类型：
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作者：
J. Lalande;R. Waxler
由于大气特性的分层，次声波通过大气管道进行长距离传播。为了研究次声波的传播，我们采用数值天气预报与气候模式相结合的大气规范。然而，这些模型并没有描述小尺度的变化，例如与内部重力波存在相关的扰动。这些波在大气动力学中发挥重要作用，在临界水平和破波高度将动量传递给平均气流。在这项研究中，我们打算描述次声波与内部重力波的相互作用，以了解在宽带次声波信号中观察到的扩展波列。我们使用内波传播的数值模型来产生背景大气状态的真实扰动。通过使用次声传播的线性全波模型，我们的目标是最终将次声特性与内波特性联系起来。我们将这些数值模型应用于不同的大气平均状态，包括重力波扰动，并将模拟结果与犹他州测试和训练靶场火箭发动机燃料消除事件记录的次声信号进行比较。通过对次声波形的深入模拟，我们的研究结果表明，将大气背景与重力波传播模型相结合，可以在一阶上解释第一平流层弧处次声场的行为。特别是，我们在平流层弧线上得到了脉冲持续时间和峰对峰振幅之间更好的匹配。该研究支持将重力波模拟与次声模拟相结合，以改进数值天气预报中的重力波参数化。
Infrasonic waves propagate at long ranges through atmospheric ducts resulting from the stratification of atmospheric properties. In order to study the infrasonic wave propagation, we resort to atmospheric specification combining Numerical Weather Prediction and climatological models. However, these models do not describe small‐scale variability such as perturbations associated to the presence of internal gravity waves. These waves play an important role in the atmospheric dynamic by transferring momentum to the mean flow at critical levels and at wave‐breaking altitudes. In this study we intend to describe the interaction of infrasonic waves with internal gravity waves in order to understand the extended wave trains observed in broadband infrasound signals. We use a numerical model for the propagation of internal waves to generate realistic perturbations of the background atmospheric states. By using a linear full‐wave model of infrasound propagation, our goal is to ultimately relate infrasound characteristics to internal waves properties. We apply those numerical models to different atmospheric mean states including gravity wave perturbations and compare the simulations to infrasound signals recorded from rocket motor fuel elimination events at the Utah Test and Training Range (UTTR). Our results, based on an intensive simulation of infrasound waveforms, show that combining atmospheric background with gravity wave propagation model is relevant to explain, to first order, the behavior of the infrasound field at the distance of the first stratospheric arc. In particular we obtain a better match between pulse duration and peak‐to‐peak amplitude along the stratospheric arc. Such study supports the use of gravity wave simulation in conjunction with infrasound modeling in order to improve gravity wave parameterization in Numerical Weather Forecasting.