Propagation of tsunami-induced acoustic-gravity waves in the atmosphere

A dynamical core of an atmospheric GCM is utilized for assessing the qualitative picture of propagation of atmospheric acoustic-gravity waves in response to perturbations generated by tsunami waves at the surface. Both resting isothermal atmosphere and modelgenerated atmosphere with realistic stratification and circulation features were considered. Shallow water tsunami model was run in two different configurations: ocean of equal depth of 4 km and ocean with realistic continents and bottom topography. Amplitude and timing of atmospheric response is analyzed as a function of vertical stratification and configuration of atmospheric jets. This approach has a potential for early tsunami detection by measuring changes in electric properties of the upper atmosphere in response to acoustic-gravity waves generated by tsunami.本研究利用大气通用环流模式（Atmospheric General Circulation Model, GCM）的动力核心，对地表海啸扰动激发的大气声重力波（acoustic-gravity waves）的传播定性特征展开评估。研究中分别考量了静止等温大气，以及具备真实层结与环流特征的模式生成大气。浅海海啸模式（shallow water tsunami model）采用两种不同配置开展数值模拟：一是深度恒定为4千米的均匀大洋，二是包含真实大陆与海底地形的大洋。本研究分析了大气响应的振幅与时序随垂直层结与大气急流（atmospheric jets）配置的变化规律。该方法具备通过监测高层大气电学特性对海啸激发声重力波的响应变化，实现海啸早期探测的潜在应用价值。