Polar, DMSP, and FAST spacecraft-based investigation of the evolution of high altitude, night side, wave Poynting flux as an energy source for low-latitude auroral electron acceleration during major storms

Previous works have shown that intense Alfvenic Poynting flux at 4-7 Re, which is capable of powering magnetically conjugate intense auroral emissions, exists on the PSBL [Wygant et al., 2000] and within the plasma sheet [Keiling et al., 2002]. It is also known that significant low-latitude auroral emissions can occur during major storms. In this study, we use electric field, magnetic field, and particle data from the Polar spacecraft along with particle data from the FAST and DMSP spacecrafts, to investigate the evolution of high altitude night side wave Poynting flux as an energy source for low latitude auroral electron acceleration over the course of major geomagnetic storms. Of particular interest is the relation of the storm time dynamics of the near tail and inner magnetosphere to the increase in the wave Poynting flux intensity by multiple orders of magnitude on low latitude field lines. This intense Poynting flux is seen to be generally sufficient to power the acceleration of low altitude electrons on similar field lines. The investigation also examines whether the intense low latitude wave Poynting flux tends to occur on relatively undistorted field lines onto which the plasma sheet has advanced, on low latitude field lines that have become distorted and stretched tailward to the plasma sheet, or both.