Michael P. Hickey

TL;DR: In this article, the directionality of quasi-monochromatic (QM) waves in the mesopause region is found to be highly anisotropic, especially during the solstices.

TL;DR: In this paper, the effect of the Tohoku earthquake and tsunami on the ionosphere near the epicenter was observed in measurements of ionospheric total electron content from 1198 GPS receivers in the Japanese GEONET network.

Abstract: [1] Recent observations have revealed large F-region electron density perturbations (∼100%) and total electron content (TEC) perturbations (∼30%) that appear to be correlated with tsunamis. The characteristic speed and horizontal wavelength of the disturbances are ∼200 m/s and ∼400 km. We describe numerical simulations using our spectral full-wave model (SFWM) of the upward propagation of a spectrum of gravity waves forced by a tsunami, and the interaction of these waves with the F-region ionosphere. The SFWM describes the propagation of linear, steady-state acoustic-gravity waves in a nonisothermal atmosphere with the inclusion of eddy and molecular diffusion of heat and momentum, ion drag, Coriolis force, and height-dependent mean winds. The tsunami is modeled as a deformation of our model lower boundary traveling at the shallow water wave speed of 200 m/s with a maximum vertical displacement of 50 cm and described by a modified Airy function in the horizontal direction. The derived vertical velocity spectrum at the surface describes the forcing at the lower boundary of the SFWM. A steady-state 1-D ionospheric perturbation model is used to calculate the electron density and TEC perturbations. The molecular diffusion strongly damps the waves in the topside (>300-km altitude) ionosphere. In spite of this, the F-region response is large, with vertical displacements of ∼2 to 5 km and electron density perturbations of ∼100%. Mean winds have a profound effect on the ability of the waves to propagate into the F-region ionosphere.

TL;DR: In this paper, a traveling front in the OH Meinel (OHM) and O2atmospheric (O2A) airglow emissions over Alice Springs, Australia, was observed.

TL;DR: In this article, a traveling front in the OH Meinel (OHM) and O2atmospheric (O2A) airglow emissions over Alice Springs, Australia, was observed.