UC San Diego

Tsunami-generated acoustic-gravity waves propagate in the atmosphere up to the ionosphere, where they have been observed to have an impact on the total electron content. We simulate numerically the propagation of linear acoustic-gravity waves in an atmosphere with vertically varying stratification and horizontal background winds. Our goal is to quantify the effects of background winds and compressibility of the atmosphere on wave transmission and reflection, and how much energy reaches the lower ionosphere before non-neutral and nonlinear effects become significant. We then extend the simulation to three dimensions to include a curved tsunami wavefront and take into account the cases when the wind is not aligned in the same direction as the tsunami propagation. Next, we consider the time-dependent effects to study the time evolution of acoustic-gravity waves in the atmosphere and their first arrival at the lower ionosphere with the long-term goal of real-time tsunami warning. Finally, the effects of stochastic variations in atmospheric parameters and in background winds are considered.