Relativistic electrons at geosynchronous orbit, interplanetary electron flux, and the 13‐month Jovian synodic year

Abstract

We report the results of a search to determine the correlation, if any, between the temporal behaviors of ≳ 0.2‐7 MeV electrons at geosynchronous orbit (∼6.6 Re) and 6‐10 MeV electrons in the interplanetary region near Earth at the period of the jovian synodic year (∼13 months). The ∼13‐month intensity variation results from the synodic interplanetary magnetic field connection of Earth to Jupiter. Direct comparison of intensity‐time flux profiles for the years 1976‐1984, ∼7 synodic jovian electron seasons, shows that the intensity envelope of peak electron flux at ∼6.6 Re6 does not appear to be correlated to the observed ∼13‐month intensity envelope of relativistic electron flux in the interplanetary region near Earth. A persistent ∼13‐month variation of geosynchronous orbit flux is not obvious, thus indicating that the intensity of electron flux at ‐6.6 Re is not directly and solely related to the intensity of jovian electron flux near Earth. We conclude that dynamic energization and redistribution processes in Earth‧s magnetosphere must be invoked to produce the intensity variations of relativistic electron flux at ∼6.6 Re and not interplanetary magnetic field connection to Jupiter.