Plasma convection in the low-latitude mantle of the near-earth magnetosphere

A detailed analysis of Geotail observations on June 1, 1997 provides evidence for the appearance of the plasma mantle at low-latitudes, Z_GSM 3 R_E for southward interplanetary magnetic field (IMF), and clarifies the characteristics of the plasma flow in the low-latitude mantle. The tailward flow speed in the mantle is 80 160 km/s, smaller than the flow speed (300 km/s) in the adjacent magnetosheath. The component of the velocity perpendicular to the magnetic field lines is predominantly poleward at speeds up to 60 km/s, and the convection tends to be stronger for |;B_Y|<|;B_Z| than for IMF |B_Y|>|B_Z|;. This polewardconvection can be interpreted as being driven by a J × B force operating on the field lines.