Overview
- The research, published November 5 in Geophysical Research Letters, analyzes HySCAI observations from Kiruna, Sweden.
- Using hyperspectral data, the team separated reflected sunlight from auroral emissions during astronomical twilight.
- The approach adapts a laboratory plasma technique by tracking sunlight-excited resonant-scattered light along the camera’s view.
- Applied to an October 21, 2023 event, the analysis found the strongest N2+ emission intensity near 200 km, above the typical ~130 km nighttime peak.
- The results support indications of higher-than-expected high-altitude N2+ density and will guide expanded measurements and model validation of ionospheric chemistry.