https://nova.newcastle.edu.au/vital/access/ /manager/Index en-au 5 Combined THEMIS and ground-based observations of a pair of substorm-associated electron precipitation events https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:17076 30 keV electron precipitation flux of 5.6 × 10⁷ el. cm⁻² sr⁻¹ s⁻¹ and a spectral gradient consistent with that observed by THEMIS, it was possible to accurately reproduce the peak observed riometer absorption at Macquarie Island (L = 5.4) and the associated NWC radio wave phase change observed at Casey, Antarctica, during the second, larger substorm. The flux levels were near to 80% of the peak fluxes observed in a similar substorm as studied by Clilverd et al. (2008). During the initial stages of the second substorm, a latitude region of 5 < L < 9 was affected by electron precipitation. Both substorms showed expansion of the precipitation region to 4 < L < 12 more than 30 min after the injection. While both substorms occurred at similar local times, with electron precipitation injections into approximately the same geographical region, the second expanded in an eastward longitude more slowly, suggesting the involvement of lower-energy electron precipitation. Each substorm region expanded westward at a rate slower than that exhibited eastward. This study shows that it is possible to successfully combine these multi-instrument observations to investigate the characteristics of substorms.]]> Wed 11 Apr 2018 16:05:29 AEST ]]> The detailed spatial structure of field-aligned currents comprising the substorm current wedge https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:16961 Wed 11 Apr 2018 15:50:05 AEST ]]>