HyENA: An Observing System Simulation Experiment for Hypothetical Energetic Neutral Atom Imagers

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This work is licensed under a Creative Commons Attribution 4.0 International License.

Authors

• Joel Tibbetts, University of New HampshireFollow
• Amy Keesee, University of New HampshireFollow
• Matina Gkioulidou, The Johns Hopkins University Applied Physics LaboratoryFollow
• Robert DeMajistre, The Johns Hopkins University Applied Physics LaboratoryFollow
• Viacheslav Merkin, The Johns Hopkins University Applied Physics LaboratoryFollow

Author ORCID Identifier

https://orcid.org/0000-0002-7898-3225

Abstract

Mesoscale plasma sheet flows are widely understood to be a critical component of the overall picture of energy, particle, and magnetic flux transport during periods of geomagnetic activity. Without simultaneous measurements with true global coverage, the short lifetime (~10 min) and localized spatial extents (~1–3 R_E in azimuth) of these structures make obtaining a global picture of their contributions to stormtime magnetosphere dynamics difficult to characterize. Energetic neutral atom (ENA) imaging can enable remote mapping of plasma energization in the magnetosphere; however, its line-of-sight integrated nature, coupled with the challenging-to-characterize attributes of the target physical phenomena, means that numerous limitations and assumptions must be addressed in order to fully understand the applicability of this observational technique. To quantify the advantages of ENA imaging as a tool for studying mesoscale flows, we have developed an observing system simulation experiment (OSSE) for simulating ENA imagers within a global geospace model environment, which we dub HyENA for Hypothetical ENA imagers. In this preliminary study, we take a purely geometric approach to investigating a "best-case" scenario for line-of-sight integrated imaging, simulating an ideal imager for three case studies of simulated mesoscale activity during a moderate storm. We demonstrate a simple method for identifying spatial extents of features in ENA images. We show that a reprojection of ENA images based on magnetic field geometry can allow for improved characterization of the equatorial components of these phenomena, and explore intrinsic limitations of single-imager ENA observations which are particularly relevant when observing complex (e.g., nested, overlapping) structures.

Department

Physics and Astronomy

Publication Date

2026

Digital Object Identifier (DOI)

https://dx.doi.org/10.34051/p/2026.17

Recommended Citation

Tibbetts, Joel; Keesee, Amy; Gkioulidou, Matina; DeMajistre, Robert; and Merkin, Viacheslav, "HyENA: An Observing System Simulation Experiment for Hypothetical Energetic Neutral Atom Imagers" (2026). Faculty Publications. 2490.
https://scholars.unh.edu/faculty_pubs/2490

Comments

This is an Author's Submitted Manuscript, submitted for publication in Journal of Geophysical Research: Space Physics