Night-Side Relativistic Electron Precipitation Bursts in the Outer Radiation Belt: Insights from ELFIN and THEMIS

TL;DR

This study investigates night-side relativistic electron precipitation bursts in the outer radiation belt, linking them to storm-time substorm injections and whistler-mode wave scattering, challenging the traditional view of night-side electron acceleration.

Contribution

It provides the first statistical analysis of night-side relativistic electron precipitation bursts and their association with substorm injections and whistler-mode wave interactions.

Findings

Night-side precipitation bursts are linked to storm-time substorm injections.

Relativistic electron scattering is likely caused by ducted whistler-mode waves.

Precipitation bursts are associated with specific storm conditions.

Abstract

Electromagnetic whistler-mode waves play a crucial role in the acceleration and precipitation of radiation belt electrons. Statistical surveys of wave characteristics suggest that these waves should preferentially scatter and precipitate relativistic electrons on the day side. However, the night-side region is expected to be primarily associated with electron acceleration. The recent low-altitude observations reveal relativistic electron precipitation in the night-side region. In this paper, we present statistical surveys of night-side relativistic electron losses due to intense precipitation bursts. We demonstrate that such bursts are associated with storm time substorm injections and are likely related to relativistic electron scattering by ducted whistler-mode waves. We also speculate on the role of injections in creating conditions favorable for relativistic electron precipitation.