Outer Radiation Belt Dropout Dynamics Following the Arrival of Two Interplanetary Coronal Mass Ejections

• Published in: Geophysical research letters Vol. 43; no. 3; pp. 978 - 987
• Main Authors: Alves, L. R., Da Silva, L. A., Souza, V. M., Sibeck, D. G., Jauer, P. R., Vieira, L. E. A., Walsh, B. M., Silveira, M. V. D., Marchezi, J. P., Rockenbach, M., Del Lago, A., Mendes, O., Tsurutani, B. T., Koga, D., Kanekal, S. G., Baker, D. N., Wygant, J. R., Kletzing, C. A.
• Format: Journal Article
• Language: English
• Published: Goddard Space Flight Center AGU 16-02-2016; John Wiley & Sons, Inc
• Subjects: adiabatic radial transport; Arrivals; Chorus waves; Coherent scattering; Computer simulation; Coronal mass ejection; Dropouts; Electron density; Electron flux; Interplanetary space; Magnetic clouds; Magnetic field; Magnetic fields; Magnetic flux; Magnetopause; magnetopause shadowing; Magnetosheath; Magnetospheres; nonadiabatic radial transport; Outer radiation belt; outer radiation belt dynamics; Particle interactions; Pitch (inclination); Pitch angle; Radiation; Radiation belts; Relativism; relativistic electron loss; Satellite observation; Scattering; Sheaths; Solar Physics; Space Sciences (General); ULF waves
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1002/2015GL067066

Magnetopause shadowing and wave-particle interactions are recognized as the two primary mechanisms for losses of electrons from the outer radiation belt. We investigate these mechanisms, sing satellite observations both in interplanetary space and within the magnetosphere and particle drift modeling. Two interplanetary shocks sheaths impinged upon the magnetopause causing a relativistic electron flux dropout. The magnetic cloud (C) and interplanetary structure sunward of the MC had primarily northward magnetic field, perhaps leading to a concomitant lack of substorm activity and a 10 day long quiescent period. The arrival of two shocks caused an unusual electron flux dropout. Test-particle simulations have shown 2 to 5 MeV energy, equatorially mirroring electrons with initial values of L 5.5can be lost to the magnetosheath via magnetopause shadowing alone. For electron losses at lower L-shells, coherent chorus wave-driven pitch angle scattering and ULF wave-driven radial transport have been shownto be viable mechanisms.