Аннотация:We study the general laws governing the propagation of low-frequency (0.1-1 Hz) electromagnetic eigen oscillations in the E layer of the ionosphere. Unlike MHD waves, these disturbances amount to a special current-diffusion process which occurs in media with anisotropic conductivity. We obtain a solution to the problem in the form of a series which expresses the sum of contributions due to each eigen oscillation. We place particular emphasis on the fundamental mode (i.e., the mode for which the damping is lowest). We show that the front of the disturbance propagates according to a diffusion law in which the period of oscillations behind the front increases with time. Because of dispersion, the characteristic scale length of the disturbance increases as the distance from the source increases. The peak of the disturbance moves at about 25 km/s, which is approximately equal to the group velocity of the fundamental mode at frequencies of 0.1-1 Hz (the frequency range where the damping is smallest). The amplitude of the signal falls of exponentially with distance. The results obtained in this paper are in qualitative agreement with the laws experimentally determined to govern the propagation of low-frequency geomagnetic disturbances.