Statistical properties of magnetic field fluctuations in the distant plasmasheet

Abstract Short ( 5 min) variations of the plasmasheet magnetic field have been examined during all intervals when ISEE -3 was at distances x R e . It is determined that short period magnetic turbulence increases by a factor of ∼3 with increasing geomagnetic activity, as indicated by AE. In contrast, long period field variations with North-then-South signatures at plasmasheet entry occur ∼2.5 times more frequently than South-then-North signatures. This result, combined with other previous ISEE -3 results, is in agreement with the interpretation that the North-South plasmasheet features are plasmoids propagating tailward. However, a statistical examination of the geomagnetic activity relationship indicates that there does not appear to be any substorm dependence on these North-South events.