Observation of the magnetosphere and ionosphere by Dynamics Explorer satellite. VIII - Whistler triggered emissions observed by DE-1 and ISIS satellites

The characteristics of whistler-triggered VLF emission data received from the DE-1, ISIS-1, and ISIS-2 satellites at the Kashima Radio Research Laboratory station are described. Latitudinal variations of the occurrence rate were obtained for emissions triggered by ducted and nonducted whistler types, and the K(p) dependence of whistler-trigggered emissions and their relation with LHR hiss are examined. The emissions triggered by ducted whistlers were found to occur frequently at L = 2.0-3.0, and those triggered by nonducted whistlers occurred in the wider region of L = 2.2-4.3. Latitudinal distributions of emissions triggered by ducted whistlers were considerably different from those of emissions triggered by nonducted whistlers, especially at high latitudes; the former show an abrupt decrease at about L = 3. The results of a statistical study of these distributions indicate that whistler-triggered emissions in the topside ionosphere are generated by the interaction of whistlers with radiation belt electrons.