Upper Atmospheric Responses to Surface Disturbances: An Observational Perspective

We review observations on the coupling between Earth's surface disturbances and the upper atmosphere. In particular, we focus on the upper atmospheric responses to atmospheric acoustic‐gravity waves generated during impulsive surface disturbance events including earthquakes, tsunamis, volcanic eruptions, and explosions. We review the theoretical background for the generation and propagation of atmospheric acoustic‐gravity waves from surface disturbance events as well as of the ionospheric plasma response to such acoustic‐gravity waves. We review a variety of observational techniques that have been successfully utilized to detect upper atmospheric perturbations induced by surface disturbances and summarize the state‐of‐the‐art knowledge on the coupling processes learnt from these observations. Finally, we touch on some most recent advances in the field and propose directions for future research.