Finite-difference time-domain modeling of infrasound from pulsating auroras and comparison with recent observations

Abstract

A FDTD model of infrasound propagation in a realistic atmosphere is used to provide quantitative interpretation of the recently reported infrasound signatures from pulsating aurora. The pressure perturbations observed on the ground are analyzed as a function of energy flux of precipitating auroral electrons and geometry and altitude localization of the source. The results indicate that fluxes on the order of 50 erg/cm2/s are needed to explain pressure waves magnitudes of 0.05 Pa observed on the ground. This energy is unlikely to be provided exclusively by precipitating electrons, and Joule heating associated with the electrojet modulated by the pulsating aurora may be responsible for part of the deposited energy. Copyright © 2010 by the American Geophysical Union.