May 2024 auroral electron characteristics from GOLD

We present an analysis of electron characteristics from the May 2024 superstorm using Global-scale Observations of the Limb and Disk (GOLD) and an atmospheric transport model, GLOW. GOLD is an Earth-observing NASA mission that collects continuous spectroscopic measurements of the Earth’s atmosphere in UV wavelengths. This mission operates onboard a geostationary satellite over Brazil and was operational during the May 2024 Superstorm. GOLD images include a wide section of the auroral oval as well as the entire disk of the Earth, which allows it to collect vast quantities of auroral data in a few key emission bands. This work utilizes the emission lines of atomic oxygen, 136.5 nm, and atomic nitrogen, 149.3 nm, as well as the molecular nitrogen emission bands between ~140 and 160 nm, in order to estimate the energy and flux of charged particles within the aurora. This is made possible by comparing the absolute intensities and flux ratios of these emission bands to a global atmospheric model, GLOW, that predicts optical emissions in the Earth’s upper atmosphere based on particle energy and flux. This work analyzes the GOLD observations from the May 2024 superstorm that corresponded to greatly enhanced auroral activity. Quantifying these auroral emissions allows us to better understand the energy input into the ionosphere. This is especially valuable on the large, Earth-sized scale that GOLD offers, and it provides a useful contrast to ground-based observations and small-scale in-situ measurements. This work represents the first attempts to use these auroral observations in a systematic way to gain insight into magnetospheric and ionospheric interactions.