The ionosphere of higher geomagnetic latitudes (L=3 andL=5) as a ulf wave filter

Abstract

Eight models of the ionosphere in the MHD approximation over the whole range of required heights(50–3000 km) are synthesized on the basis of other theoretical studies and a number of empirical methods for the purposes of modelling the ionospheric filtration of the natural micropulsation (Pc1) signal. The models represent a vertically inhomogeneous and dissipative daytime and nighttime ionosphere of higher latitudes in two regions (L=3 and L=5) of the Northern Hemisphere in summer under low (F10.7=70) and high (F10.7=200) solar activity. The higher ionosphere (h>200 km) is approximated by a quasineutral oxygen-hydrogen plasma(O+,H+) taking into account the wave-dissipating effects of the neutral component(O, He). The procedure of computing the physical parameters, locally characterizing the medium of the ionosphere, is demonstrated.