Nightside Electron Precipitation Patterns as Observed by ELFIN and CIRBE CubeSats

Authors

• Kun Zhang, University of California, Los AngelesFollow
• Anton V. Artemyev, University of California, Los Angeles
• Xinlin Li, University of Colorado Boulder
• Xiao-Jia Zhang, University of Colorado Boulder
• Vassilis Angelopoulos, University of California, Los Angeles
• Yang Mei, University of Colorado Boulder
• Zheng Xiang, University of Colorado Boulder
• Niklas Grimmich, Technische Universität Braunschweig

Submitting Campus

Daytona Beach

Department

Physical Sciences

Document Type

Article

Abstract/Description

The rapidly expanding fleet of low-altitude CubeSats equipped with energetic particle detectors brings new opportunities for monitoring the dynamics of the radiation belt and near-Earth plasma sheet. Despite their small sizes, CubeSats can carry state-of-the-art instruments that provide electron flux measurements with finer energy resolution and broader energy coverage, compared to conventional missions such as POES satellites. The recently launched CIRBE CubeSat measures 250–6,000 keV electrons with extremely high energy resolution, however, CIRBE typically only measures locally-trapped electrons and cannot directly measure the precipitating electrons. This work aims to develop a technique for identifying indications of nightside precipitation using the locally-trapped electron measurements by the CIRBE CubeSat. This study focuses on two main types of drivers for nightside precipitation: electron scattering by the curvature of magnetic field lines in the magnetotail current sheet and electron scattering by resonance with electromagnetic ion cyclotron (EMIC) waves. Using energy and pitch-angle resolved electron fluxes from the low-altitude ELFIN CubeSat, we reveal the features that distinguish between these two precipitation mechanisms based solely on locally-trapped flux measurements. Then we present measurements from four CIRBE orbits and demonstrate the applicability of the proposed technique to the investigation of nightside precipitation using CIRBE observations, enabling separation between precipitation induced by curvature scattering and EMIC waves in nearby regions. Our study underscores the feasibility of employing high-energy-resolution CIRBE measurements for detecting nightside precipitation of relativistic electrons. Additionally, we briefly discuss outstanding scientific questions about these precipitation patterns that could be addressed with CIRBE measurements.

Publication Title

Journal of Geophysical Research: Space Physics

DOI

https://doi.org/10.1029/2024JA033051

Publisher

John Wiley & Sons, Inc

Grant or Award Name

NASA awards 80NSSC23K0108, 80NSSC23K0403, 80NSSC24K0558, and NSF grants AGS‐ 1242918, AGS‐2019950, and AGS‐ 2021749, NASA Grant 80NSSC19K0995

Additional Information

Dr. Zhang was not affiliated with Embry-Riddle Aeronautical University at the time this paper was published.

Scholarly Commons Citation

Zhang, K., Artemyev, A. V., Li, X., Zhang, X.‐J., Angelopoulos, V., Mei, Y., et al. (2024). Nightside electron precipitation patterns as observed by ELFIN and CIRBE CubeSats. Journal of Geophysical Research: Space Physics, 129, e2024JA033051. https://doi.org/10.1029/ 2024JA033051