A RECONCILIATION OF PROPAGATION MODES OF AURORAL KILOMETRIC RADIATION

The propagation modes of auroral kilometric radiation (AKR) are theoretically investigated by three-dimensional ray tracing using an electron density model based on the auroral plasma cavity. Both right-hand extraordinary (R-X) mode and left-hand ordinary (L-O) mode observations are explained in a consistent manner. L-O mode waves can propagate within a wider region than R-X mode waves. The R-X mode is dominant at high latitudes because it is stronger. The L-O mode is received at lower latitudes which the R-X mode waves cannot reach because of refraction and reflection mainly in the vicinity of the source and the plasmapause. 20 refs.