Characteristic energy range of electron scattering due to plasmaspheric hiss

Journal Article · Tue Nov 15 00:00:00 EST 2016 · Journal of Geophysical Research. Space Physics

DOI:https://doi.org/10.1002/2016JA023311· OSTI ID:1402625

Ma, Q. ^[1]; Li, W. ^[2]; Thorne, R. M. ^[1]; Bortnik, J. ^[1]; Reeves, G. D. ^[3]; Kletzing, C. A. ^[4]; Kurth, W. S. ^[4]; Hospodarsky, G. B. ^[4]; Spence, H. E. ^[5]; Baker, D. N. ^[6]; Blake, J. B. ^[7]; Fennell, J. F. ^[7]; Claudepierre, S. G. ^[7]; Angelopoulos, V. ^[8]

---

1. Univ. of California, Los Angeles, CA (United States). Dept. of Atmospheric and Oceanic Sciences
2. Univ. of California, Los Angeles, CA (United States). Dept. of Atmospheric and Oceanic Sciences; Boston Univ., MA (United States). Center for Space Physics
3. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
4. Univ. of Iowa, Iowa City, IA (United States). Dept. of Physics and Astronomy
5. Univ. of New Hampshire, Durham, NH (United States). Inst. for the Study of Earth, Oceans, and Space
6. Univ. of Colorado, Boulder, CO (United States). Lab. for Atmospheric and Space Physics
7. The Aerospace Corporation, Los Angeles, CA (United States). Space Sciences Dept.
8. Univ. of California, Los Angeles, CA (United States). Dept. of Earth, Planetary and Space Sciences. Inst. of Geophysics and Planetary Physics

In this paper, we investigate the characteristic energy range of electron flux decay due to the interaction with plasmaspheric hiss in the Earth's inner magnetosphere. The Van Allen Probes have measured the energetic electron flux decay profiles in the Earth's outer radiation belt during a quiet period following the geomagnetic storm that occurred on 7 November 2015. The observed energy of significant electron decay increases with decreasing L shell and is well correlated with the energy band corresponding to the first adiabatic invariant μ = 4–200 MeV/G. The electron diffusion coefficients due to hiss scattering are calculated at L = 2–6, and the modeled energy band of effective pitch angle scattering is also well correlated with the constant μ lines and is consistent with the observed energy range of electron decay. Using the previously developed statistical plasmaspheric hiss model during modestly disturbed periods, we perform a 2-D Fokker-Planck simulation of the electron phase space density evolution at L = 3.5 and demonstrate that plasmaspheric hiss causes the significant decay of 100 keV–1 MeV electrons with the largest decay rate occurring at around 340 keV, forming anisotropic pitch angle distributions at lower energies and more flattened distributions at higher energies. Finally, our study provides reasonable estimates of the electron populations that can be most significantly affected by plasmaspheric hiss and the consequent electron decay profiles.

• Research Organization: Los Alamos National Lab. (LANL), Los Alamos, NM (United States); The Aerospace Corporation, Los Angeles, CA (United States); Univ. of California, Los Angeles, CA (United States)
• Sponsoring Organization: Air Force Office of Scientific Research (AFOSR) (United States); National Aeronautics and Space Administration (NASA) (United States); National Science Foundation (NSF) (United States); USDOE Office of Science (SC), Fusion Energy Sciences (FES) (SC-24)
• Grant/Contract Number: AC52-06NA25396; SC0010578
• OSTI ID: 1402625
• Report Number(s): LA-UR--17-20875
• Journal Information: Journal of Geophysical Research. Space Physics, Journal Name: Journal of Geophysical Research. Space Physics Journal Issue: 12 Vol. 121; ISSN 2169-9380
• Publisher: American Geophysical Union
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
Van Allen Probes observation
electron flux decay
pitch angle scattering
plasmaspheric hiss