MLT Dependence of Relativistic Electron Scattering Into the Drift Loss Cone: Measurements From ELFIN‐L on Board Lomonosov Spacecraft

Shprits, Yuri Y. ORCIDiD
Michaelis, Ingo ORCIDiD
Wang, Dedong ORCIDiD
Allison, Hayley ORCIDiD
Vasile, Ruggero
Runov, Andrei ORCIDiD
Drozdov, Alexander ORCIDiD
Russell, Christopher T. ORCIDiD
Kalegaev, Vladimir ORCIDiD
Smirnov, Artem ORCIDiD

DOI: https://doi.org/10.1029/2023GL103342
Persistent URL: http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/11714
Shprits, Yuri Y.; Michaelis, Ingo; Wang, Dedong; Allison, Hayley; Vasile, Ruggero; Runov, Andrei; Drozdov, Alexander; Russell, Christopher T.; Kalegaev, Vladimir; Smirnov, Artem, 2023: MLT Dependence of Relativistic Electron Scattering Into the Drift Loss Cone: Measurements From ELFIN‐L on Board Lomonosov Spacecraft. In: Geophysical Research Letters, 50, 12, DOI: https://doi.org/10.1029/2023GL103342. 

Abstract

Abstract

There have been a number of theories proposed concerning the loss of relativistic electrons from the radiation belts. However, direct observations of loss were not possible on a number of previous missions due to the large field of view of the instruments and often high‐altitude orbits of satellites that did not allow researchers to isolate the precipitating electrons from the stably trapped. We use measurements from the ELFIN‐L suit of instruments flown on Lomonosov spacecraft at LEO orbit, which allows us to distinguish stably trapped from the drift loss cone electrons. The sun‐synchronous orbit of Lomonosov allows us to quantify scattering that occurred into the loss cone on the dawn‐side and the dusk‐side magnetosphere. The loss at MeV energies is observed predominantly on the dawn‐side, consistent with the loss induced by the chorus waves. The companion data publication provides processed measurements.


Plain Language Summary: There have been a number of models proposed concerning the loss of relativistic electrons from radiation belts. However, the direct observations of loss have been missing, as for most of the previous missions; the large aperture telescopes could not isolate the precipitating electrons from being stably trapped. In this study, we use measurements from ELFIN‐L on Lomonosov that allow for such separation and allow us to distinguish stably trapped from precipitating particles. We can also identify the particles that will be lost within one drift around the Earth, the so‐called drift loss cone. For understanding the loss processes and differentiating between them, it's crucially important to quantify where in local magnetic time these electrons will be scattered into the drift loss cone. Measurements from the ELFIN‐L instrument show that the loss at MeV energies is observed predominantly on the dawn side, consistent with the loss induced by the so‐called chorus plasma waves.


Key Points:

ELFIN‐L measurements allow comparing scattering into the loss cone on the dawn and dusk side

Processed Level‐3 measurements are provided in the data publication

Most of the relativistic electrons are scattered into the drift loss cone on the dawn side