Scattering mechanism responsible for relativistic electron precipitation during the burst

Ascertain the specific scattering mechanism that filled the loss cone and precipitated the relativistic electrons during the 19:41 UT burst observed by ELFIN, distinguishing among candidates such as magnetic curvature scattering upon detrapping from dipolarized fields and alternative wave–particle or field-aligned processes.

Background

ELFIN observed a near-isotropic pitch-angle distribution and strong precipitation during the burst, implying efficient scattering into the atmospheric loss cone. The authors discuss possibilities such as current-sheet curvature scattering upon escape from localized dipolarized regions, but lack direct in-situ evidence from the acceleration site.

Given the rapidity and localization of the event, the responsible scattering process must be compact and efficient, yet cannot be confirmed with the available observations.

References

Although we cannot confirm the scattering mechanism, our evidence suggests that it is compact and efficient.

— A Localized Burst of Relativistic Electrons in Earth's Plasma Sheet: Low- and High-Altitude Signatures During a Substorm  (2410.16412 - Shumko et al., 2024) in Discussion and Conclusions (summary paragraph)