FTE (Flux Transfer Event) Like Variations in the Geomagnetic Field at Ground Based Conjugate Stations in the Cusp Regions

摘要

Magnetic field data acquired at the conjugate pair stations Frobisher Bay/South Pole were carefully studied to examine the nature of the magnetic signatures identified as possible ionospheric signatures of flux transfer events (FTEs). It was found, in an examination of data over the interval July-November 1985, many events, covering a wide range of amplitudes, that are suggestive of intense field-aligned currents convected over the observing stations. All the events were found to have a half-width in time of a few minutes and to be conjugate. All of the events have vertical magnetic field perturbations which imply field-aligned currents in the same direction (either into or out of the ionosphere) in both hemispheres. The implications of these results for the identification of these events with FTEs and contemporary models for dayside reconnection and field-aligned systems will be discussed.