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Wilson LB, Chen LJ, Wang S, Schwartz SJ, Turner DL, Stevens ML, Kasper JC, Osmane A, Caprioli D, Bale SD, Pulupa MP, Salem CS, Goodrich KA. Electron Energy Partition across Interplanetary Shocks. I. Methodology and Data Product. THE ASTROPHYSICAL JOURNAL. SUPPLEMENT SERIES 2019; 243:10.3847/1538-4365/ab22bd. [PMID: 31806920 PMCID: PMC6894189 DOI: 10.3847/1538-4365/ab22bd] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Analyses of 15,314 electron velocity distribution functions (VDFs) within ±2 hr of 52 interplanetary (IP) shocks observed by the Wind spacecraft near 1 au are introduced. The electron VDFs are fit to the sum of three model functions for the cold dense core, hot tenuous halo, and field-aligned beam/strahl component. The best results were found by modeling the core as either a bi-kappa or a symmetric (or asymmetric) bi-self-similar VDF, while both the halo and beam/strahl components were best fit to bi-kappa VDF. This is the first statistical study to show that the core electron distribution is better fit to a self-similar VDF than a bi-Maxwellian under all conditions. The self-similar distribution deviation from a Maxwellian is a measure of inelasticity in particle scattering from waves and/or turbulence. The ranges of values defined by the lower and upper quartiles for the kappa exponents are κ ec ~ 5.40-10.2 for the core, κ eh ~ 3.58-5.34 for the halo, and κ eb ~ 3.40-5.16 for the beam/strahl. The lower-to-upper quartile range of symmetric bi-self-similar core exponents is s ec ~ 2.00-2.04, and those of asymmetric bi-self-similar core exponents are p ec ~ 2.20-4.00 for the parallel exponent and q ec ~ 2.00-2.46 for the perpendicular exponent. The nuanced details of the fit procedure and description of resulting data product are also presented. The statistics and detailed analysis of the results are presented in Paper II and Paper III of this three-part study.
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Affiliation(s)
- Lynn B Wilson
- NASA Goddard Space Flight Center, Heliophysics Science Division, Greenbelt, MD, USA
| | - Li-Jen Chen
- NASA Goddard Space Flight Center, Heliophysics Science Division, Greenbelt, MD, USA
| | - Shan Wang
- NASA Goddard Space Flight Center, Heliophysics Science Division, Greenbelt, MD, USA
- Astronomy Department, University of Maryland, College Park, Maryland, USA
| | - Steven J Schwartz
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Boulder, CO, USA
| | - Drew L Turner
- Space Sciences Department, The Aerospace Corporation, El Segundo, CA, USA
| | - Michael L Stevens
- Harvard-Smithsonian Center for Astrophysics, Harvard University, Cambridge, MA, USA
| | - Justin C Kasper
- University of Michigan, Ann Arbor, School of Climate and Space Sciences and Engineering, Ann Arbor, MI, USA
| | - Adnane Osmane
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - Damiano Caprioli
- Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL, USA
| | - Stuart D Bale
- University of California Berkeley, Space Sciences Laboratory, Berkeley, CA, USA
| | - Marc P Pulupa
- University of California Berkeley, Space Sciences Laboratory, Berkeley, CA, USA
| | - Chadi S Salem
- University of California Berkeley, Space Sciences Laboratory, Berkeley, CA, USA
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Wu F, Vainchtein D, Artemyev A. Nonlinear resonances generate large-scale convection cells in phase space. Phys Rev E 2019; 99:020201. [PMID: 30934323 DOI: 10.1103/physreve.99.020201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Indexed: 11/07/2022]
Abstract
It is well known that resonance phenomena can destroy adiabatic invariance and cause chaos and mixing. In the present Rapid Communication, we show that a nonlinear wave-particle resonant interaction may do the opposite-generate large-scale coherent structures in phase space. The combined action of the drift due to nonlinear scattering on resonance and trapping (capture) into resonance creates a convection cell-like structure, where the areas of particle acceleration and deceleration are macroscopically separated. At the same time, nonlinear scattering also creates a diffusion that cause mixing on and between the energy levels.
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Affiliation(s)
- Fan Wu
- Key Laboratory of Traffic Safety on Track, Ministry of Education, School of Traffic & Transportation Engineering, Central South University, Changsha 410075, Hunan, China
| | - Dmitri Vainchtein
- Nyheim Plasma Institute, Drexel University, Camden, New Jersey 08103, USA.,Space Research Institute, Moscow 117997, Russia
| | - Anton Artemyev
- Space Research Institute, Moscow 117997, Russia.,Institute of Geophysics and Planetary Physics, University of California, Los Angeles, California 90095, USA
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