An interpretation of the cross-phase spectrum of geomagnetic pulsations bythe field line resonance theory

The cross-phase spectrum of the magnetic fields at two closely spaced stati ons located on the same meridian can be used to determine the field line re sonance frequencies in the magnetosphere. The model of two harmonic oscilla tors previously proposed in the literature to interpret this technique, how ever, deviates from the traditional field line resonance model and it fails to interpret the cross-phase spectrum for the Z component. We show that th e cross-phase spectrum can be interpreted by traditional field line resonan ce theory with consideration of ionospheric effects even in the presense of a continuum of non-interacting resonating field lines.