Mesopause Airglow Disturbances Driven by Nonlinear Infrasonic Acoustic Waves Generated by Large Earthquakes
Pavel Inchin, J. B. Snively, A. Williamson, Diego Melgar, J. Aguilar Guerrero, M. D. Zettergren
Abstract
Abstract Near‐epicentral mesopause airglow perturbations, driven by infrasonic acoustic waves (AWs) during a nighttime analog of the 2011 M9.1 Tohoku‐Oki earthquake, are simulated through the direct numerical computation of the 3D nonlinear Navier‐Stokes equations. Surface dynamics from a forward seismic wave propagation simulation, initialized with a kinematic slip model and performed with the SPECFEM3D_GLOBE model, are used to excite AWs into the atmosphere from ground level. Simulated mesopause airglow perturbations include steep oscillations and persistent nonlinear depletions up to 50 % and 70 % from the background state, respectively, for the hydroxyl OH(3,1) and oxygen O( 1 S) 557.7‐nm emissions. Results suggest that AWs excited near a large earthquake's epicenter may be strong enough to drive fluctuations in mesopause airglow, some which may persist after the AWs have passed, that could be readily detectable with ground‐ and/or satellite‐based imagers. Synthetic data demonstrate that future airglow observations may be used for the characterization of earthquake mechanisms and surface seismic waves propagation, potentially complementing tsunami early‐warning systems based on total electron content (TEC) observations.