Jupiter's polar ionospheric flows: Measured intensity and velocity variations poleward of the main auroral oval

Abstract

Recent analysis of high-resolution spectra of Doppler-shifted H+3 emission from the auroral/polar regions of Jupiter revealed a complex wind system, with a persistent auroral electrojet and strong anti-sunward flows in a region of lesser intensity centred around the magnetic pole [Stallard et al., 2001]. This region, which we have called the Dark Polar Region (DPR), is re-investigated, trans forming the observed line-of-sight velocities into a frame of reference fixed with respect to the magnetic pole. The DPR is shown to include a region essentially stagnant in this frame of reference (the f-DPR). We identify it as a region coupled to open magnetotail field lines. There is also a transition region in which the ion velocity returns to corotation (the r-DPR).