Spatial Structure and Polarization of Geomagnetic Pulsations Observed on the Ground.

Abstract

At low latitudes, the phase of H component of the ground magnetic perturbation can be expected to be independent of the latitude for low-frequency geomagnetic pulsations. Because of such a spatial phase structure of the H component, it is found that the D component has a 180° out-of-phase relation between the northern and southern hemispheres and its amplitude increases monotonously from the magnetic equator to higher latitudes. It is also shown that the sense of rotation of the magnetic perturbation vector in the H-D plane is clockwise and counterclockwise for the eastward and westward propagations, respectively, in the northern hemisphere and vice versa in the southern hemisphere. On the other hand, since the spatial phase structure of the H component far away from the magnetic equator becomes more complicated as the latitude increases, the correlation between signal propagation sense and horizontal polarization may deteriorate at high latitues. For the amplitudes of H and D components due to the compressional component of the magnetic field incident upon the ionosphere their upper bounds are also given.