Energetic electrons at 6.6REduring the January 13-14, 1967, geomagnetic storm

Abstract

The trapped, energetic (Eϵ > 0.4 Mev to > 3.0 Mev) electron fluxes at synchronous altitude are examined during the January 13–14, 1967, geomagnetic storm. Except for a short period after the sudden commencement (sc) at 1202 UT, day 13 (0202 local time), the measured electrons were observed to be stably trapped for about the first twelve hours after the sc. However, the values of the electron fluxes in the local morning and at local noon were quite different than those generally observed during quiet periods. About two hours after local noon, at 2324 UT, day 13, the electron flux dropped sharply by two orders of magnitude in response to a sudden decrease in the magnetic field observed at the satellite. Recovery of the electron flux occurred in a few minutes. About 40 minutes later, 0007 UT, day 14, the electron fluxes were essentially wiped out at the time of an observed reversal in the magnetic field at the satellite. During two separate approximately 10-minute periods after this 0007 UT, day 14, wipeout, the observed particle fluxes indicate that the satellite encountered a region of space with characteristics very different from the normal magnetospheric trapping region. The data during these times are consistent with the interpretation from the magnetic field observations that the satellite was outside the magnetopause. Correlation of the electron data during the storm is made with the satellite magnetometer data and with the magnetometer data from several ground stations.