Nf. Arnold et Tr. Robinson, A MECHANISM FOR GENERATING NONLINEAR ELECTRON-DENSITY DISTRIBUTIONS WHEN FORCED BY LARGE-AMPLITUDE MONOCHROMATIC GRAVITY-WAVES, Annales geophysicae, 12(7), 1994, pp. 688-690
Linear theory predicts that disturbances in the ionospheric electron d
ensity field will closely resemble the characteristics of the forcing
gravity wave. In this short note a simple mechanistic model which incl
udes the effects of non-zero divergence of the nonlinear flux has been
developed. The model indicates that higher frequency modes are genera
ted when the gravity wave amplitude is sufficiently large. The harmoni
cs can exhibit highly non-sinusoidal behaviour and this has implicatio
ns for attempts to interpret medium-scale TIDs in terms of acoustic gr
avity wave activity.