Energetic Particle Injection During Short Isolated Bubble as Seen in RCM Simulation and Spacecraft Observations in the Flow Braking Region

• Published in: Journal of geophysical research. Space physics 2023-12, Vol.128 (12), p.n/a
• Main Authors: Sergeev, V., Yang, Jian, Sun, Weiqin, Runov, A., Angelopoulos, V., Artemyev, A.
• Format: Article
• Language: English
• Subjects: Braking; Bubbles; Cloud formation; Convection; Density; Depletion; Drift; Electron clouds; Electron flux; Electrons; Energetic particles; Flow; Fluctuations; Geosynchronous orbits; Injection; injections; Intrusion; Magnetic flux; Magnetic variations; Magnetospheres; magnetotail; Magnetotails; Particle acceleration; Particle injection; Particle physics; Plasma; Plasma bubbles; Plasma jets; Proton flux; Protons; Radiation; Radiation belts; Simulation; Spacecraft; substorms
• ISSN: 2169-9380; 2169-9402
• DOI: 10.1029/2023JA031906

Although energetic particle (EP) injections are commonly thought to be formed by the flow burst intrusion from the magnetotail, important details and quantitative aspects of their transport, acceleration and flow braking need further investigation and understanding. Motivated by frequent observations of short transient EP injections being not associated with substorms, we analyze high‐resolution Rice Convection Model simulations of a short (5‐min long) localized (∼3RE width) density depletion (evacuating 90% of flux tube content) initiated at the tailward simulation boundary (∼18RE) and allowed to evolve within an otherwise typical plasma sheet environment. We note that, driven by betatron‐like acceleration, the peak EP flux at fixed energy dramatically increases in a couple of minutes when the bubble head enters the inner magnetosphere at r