Convection in the distant magnetotail under extremely quiet and weakly disturbed conditions

Measurements of the magnetic field and low-energy plasma by the Geotail spa cecraft have been used to study magnetospheric convection in the distant ta il at X = - (79-200) RE under extremely quiet and weakly disturbed conditio ns. The analysis was carried out separately for the tail lobes and the plas ma sheet; these regions were identified by plasma and magnetic field parame ters. It is Shown that plasmas in the northern and southern tail lobes move tailward along magnetic field lines at the same time as magnetic field lin es converge towards the plasma sheet, The main processes occurring in the d istant tail under extremely quiet conditions (northward interplanetary magn etic field) and weakly disturbed conditions (southward IMF) are very simila r, excluding the passage of high-speed tailward plasmoids, which are obviou sly generated in the near-Earth plasma sheet. Magnetic turbulence, that is, fluctuations of the magnetic field occurring against the background of a t otally northward field (B-Z>0), consistent with intense oscillations in the plasma now V-x component, is typical of all conditions. It is concluded th at the stretched and antiparallel field lines of the northern and southern tail lobes are reconnected in the plasma sheet. Tail lobe plasma constantly enters the plasma sheet, where the lobe magnetic field energy converts int o the kinetic energy of the plasma producing the magnetic turbulence. It se ems likely that the direction (northward or southward) of the IMF is not ne cessary for tail formation, and processes in the near tail (substorm activi ty) does not strongly influence reconnection in the distant tail.