This project is a synergistic study of radar and optical measurements for investigating and characterizing the occurrence of Naturally Enhanced Ion Acoustic Lines (NEIALs) with coincident auroral fine structures. While it is known that NEIALs are a manifestation of large-amplitude ion acoustic waves and potentially Langmuir waves and/or large current densities, their influence and feedback on the electromagnetic and particle energy transfer within the magnetosphere-ionosphere system is not well understood. The project will make use of common-volume observations of the nighttime auroral ionosphere with ground-based Electron Multiplying Charged Couple Device (EMCCD) imagers and the Poker Flat Incoherent Scatter Radar (PFISR) to gain an improved understanding of NEIAL generation mechanisms. A suite of six narrowfield imagers will be used, each equipped with a different narrow bandpass filter, imaging multiple auroral emission lines simultaneously in order to derive the spatial distribution of the precipitating electron energy. The observations will take place during moon down periods, in both campaign and remote operation modes. The theory and modeling components will be investigated in partnership with an international collaborator.
