Physical nature of the diffuse plasma resonances in the ionosphere


  • Vladimir A. Osherovich


A recently developed theory of force-free electromagnetic oscillations (Osherovich, 1985, 1986), is employed to interpret the diffuse plasma resonances stimulated by topside ionospheric sounders at the frequencies ƒDn. The main prediction of the theory, namely, that the spectrum of frequencies should be proportional to n1/2, n = 1, 2, 3, …, is checked against observations. It is found that ƒDn ≈ 0.95(ƒNƒH;)1/2n1/2 is a fair approximation for diffuse ionospheric resonances, where ƒN and ƒH are the plasma and electron gyrofrequencies, respectively.