Jovian electron modulations by the solar wind interaction with the magnetosphere

Variations of energetic electrons released from the Jovian magnetosphere ar e investigated in detail by using data from three spacecraft, Pioneer 10, 1 1, and Ulysses. Analyses with the three spacecraft data confirmed that the Jovian electrons are modulated by the dynamic pressure of the solar wind at the position of Jupiter. It is also found that the release rate of energet ic electrons is controlled by the polarity of IMF having dawn-dusk or latit udinal dependence. The enhancements of released electron flux were detected during the toward polarity of IMF when the spacecraft were located in the upstream or dawn side of Jupiter. On the other hand, Ulysses detected enhan cement in away polarity of IMF when the spacecraft was on the duskside of s outhern hemisphere. We made a simulation to reproduce the electron variatio n of Jovian electrons observed by Pioneer 11 considering the convective and diffusive transport in the interplanetary medium. According to the simulat ion, the observed enhancements of electron flux originating from Jupiter ar e well represented by the coupling of both the source modulation at the Jov ian magnetosphere and the transport effect in the interplanetary medium.