Altitude extension of auroral potential structures by event-based and statistical studies Original Research Article

Lots of observations below about 13000 km altitude favour the U-shaped potential model above auroral arcs. Recent observational findings above 20000 km indicate, however, that the U-shaped potential related to stable auroral arcs does not usually extend to that altitude. To resolve the dilemma, we have suggested an O-shaped potential model. Here we show how an O-shaped potential can form self-consistently by assuming plasma waves that energise ∼50–400 eV electrons in the parallel direction. The obtained “cooperative” model invokes both waves and O-shaped potential structures in a nontrivial manner to produce inverted-V spectra and auroral arcs, and it is compatible with satellite observations at both low and high altitude.