Analysis of Energetic Electron Precipitation and its Associated Drivers Using Multi-Point Observations

Abstract:

Precipitation of energetic electrons from the radiation belts into the Earth’s upper atmosphere is one of the important loss mechanisms in the magnetosphere. Additionally, precipitation of energetic electrons has effects on the atmospheric composition and ionization levels. Characterizing the precipitation together with understanding its drivers is a fundamental goal in the field of magnetospheric physics. It is known that various magnetospheric plasma waves (i.e., chorus, plasmaspheric hiss, electromagnetic ion cyclotron waves, etc.) play an important role in scattering energetic electrons into the loss cone. However, each plasma wave type interacts differently with the electron population and drives precipitation with different energy spectra and structures, and in different MLT sectors. Another driver of energetic electron precipitation is current sheet scattering, which occurs when the electron gyroradius is comparable to the field line curvature radius. This phenomenon is generally expected to dominate in the night sector.

This study aims to identify events of energetic electron precipitation occurring at Low-Earth-Orbit (LEO) and investigate the drivers of such precipitation using coordinated multi-satellite observations. Many available satellites provide particle precipitation data at LEO (eg., POES, FIREBIRD-II, ELFIN) and can pass through the conjugate location of magnetospheric satellites (i.e. Van Allen Probes, THEMIS, MMS, etc.), which provide particle and wave information in the near-equatorial region. By connecting these multi-point observations, we aim to identify the drivers and characteristics of the resulting electron precipitation.