[1] A massive rotating equatorial plasma sheet dominates Jupiter's magnetosphere and the solar wind and the interplanetary magnetic field ( IMF) are not thought to be as important as at Earth. We simulated the Jovian magnetosphere for northward IMF starting from a steady state for southward IMF. About 46 hours after the northward IMF reached the dayside magnetopause reconnection started in the Jovian magnetotail and a plasmoid was launched tailward. This was followed by the formation and ejection of three more plasmoids. In each case the reconnection line (X-line) moved tailward with the plasmoid. Magnetic flux tubes from the X-line moved toward and around Jupiter ending up back in the plasma sheet where they were available for additional reconnection. A new reconnection line then formed, a plasmoid was ejected and the process repeated. These phenomena occurred with an average period of 34.3 hours.