Observations of Ion Upflow in Conjunction With Pulsating Aurora

The Enhanced Polar Outflow Probe (e-POP) satellite was launched by SpaceX on September 29, 2013 into a polar orbit. Near magnetic midnight on March 3, 2014, e-POP traversed a region of pulsating aurora over eastern Canada. Here, we present an analysis of in-situ optical, ion, electron, and magnetometer data recorded by instrumentation onboard the e-POP satellite in conjunction with ground-based observations. The observed small-scale field aligned currents (FAC) and soft electron precipitation suggest a Type II ion upflow event which occurred in coincidence with the pulsating aurora. In the Type II ion upflow process, precipitating electrons collisionally heat background electrons at lower altitudes, causing them to expand upward adiabatically. This expanding electron gas produces an electron density gradient, which gives rise to an ambipolar electric field that then accelerates ions to higher altitudes where they may be further energized by wave-particle interactions. Features in this event are similar to those recorded by ground-based All-Sky Imagers and PFISR on February 7, 2017, which also show signatures of Type II ion upflow alongside pulsating aurora. Data from both events are presented and analyzed. Of particular interest in both events are the small-scale FACs and soft electron precipitation that occur alongside red aurora.