1
|
Sitnov M, Birn J, Ferdousi B, Gordeev E, Khotyaintsev Y, Merkin V, Motoba T, Otto A, Panov E, Pritchett P, Pucci F, Raeder J, Runov A, Sergeev V, Velli M, Zhou X. Explosive Magnetotail Activity. SPACE SCIENCE REVIEWS 2019; 215:31. [PMID: 31178609 PMCID: PMC6528807 DOI: 10.1007/s11214-019-0599-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 04/27/2019] [Indexed: 06/01/2023]
Abstract
Modes and manifestations of the explosive activity in the Earth's magnetotail, as well as its onset mechanisms and key pre-onset conditions are reviewed. Two mechanisms for the generation of the pre-onset current sheet are discussed, namely magnetic flux addition to the tail lobes, or other high-latitude perturbations, and magnetic flux evacuation from the near-Earth tail associated with dayside reconnection. Reconnection onset may require stretching and thinning of the sheet down to electron scales. It may also start in thicker sheets in regions with a tailward gradient of the equatorial magnetic field B z ; in this case it begins as an ideal-MHD instability followed by the generation of bursty bulk flows and dipolarization fronts. Indeed, remote sensing and global MHD modeling show the formation of tail regions with increased B z , prone to magnetic reconnection, ballooning/interchange and flapping instabilities. While interchange instability may also develop in such thicker sheets, it may grow more slowly compared to tearing and cause secondary reconnection locally in the dawn-dusk direction. Post-onset transients include bursty flows and dipolarization fronts, micro-instabilities of lower-hybrid-drift and whistler waves, as well as damped global flux tube oscillations in the near-Earth region. They convert the stretched tail magnetic field energy into bulk plasma acceleration and collisionless heating, excitation of a broad spectrum of plasma waves, and collisional dissipation in the ionosphere. Collisionless heating involves ion reflection from fronts, Fermi, betatron as well as other, non-adiabatic, mechanisms. Ionospheric manifestations of some of these magnetotail phenomena are discussed. Explosive plasma phenomena observed in the laboratory, the solar corona and solar wind are also discussed.
Collapse
Affiliation(s)
- Mikhail Sitnov
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | | | | | - Evgeny Gordeev
- Earth’s Physics Department, Saint Petersburg State University, St. Petersburg, Russia
| | | | - Viacheslav Merkin
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - Tetsuo Motoba
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | | | - Evgeny Panov
- Space Research Institute, Austrian Academy of Sciences, Graz, Austria
| | - Philip Pritchett
- Department of Physics and Astronomy, University of California, Los Angeles, CA USA
| | - Fulvia Pucci
- National Institute for Fusion Science, National Institutes of Natural Sciences, Toki, 509-5292 Japan
- Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ USA
| | - Joachim Raeder
- Institute for the Study of Earth, Oceans and Space, University of New Hampshire, Durham, NH USA
| | - Andrei Runov
- Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA USA
| | - Victor Sergeev
- Earth’s Physics Department, Saint Petersburg State University, St. Petersburg, Russia
| | - Marco Velli
- University of California Los Angeles, Los Angeles, CA 90095 USA
| | - Xuzhi Zhou
- School of Earth and Space Sciences, Peking University, Beijing, 100871 China
| |
Collapse
|
2
|
Reeves GD, Friedel RHW, Larsen BA, Skoug RM, Funsten HO, Claudepierre SG, Fennell JF, Turner DL, Denton MH, Spence HE, Blake JB, Baker DN. Energy-dependent dynamics of keV to MeV electrons in the inner zone, outer zone, and slot regions. JOURNAL OF GEOPHYSICAL RESEARCH. SPACE PHYSICS 2016; 121:397-412. [PMID: 27818855 PMCID: PMC5070526 DOI: 10.1002/2015ja021569] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 12/18/2015] [Accepted: 12/22/2015] [Indexed: 06/01/2023]
Abstract
We present observations of the radiation belts from the Helium Oxygen Proton Electron and Magnetic Electron Ion Spectrometer particle detectors on the Van Allen Probes satellites that illustrate the energy dependence and L shell dependence of radiation belt enhancements and decays. We survey events in 2013 and analyze an event on 1 March in more detail. The observations show the following: (a) at all L shells, lower energy electrons are enhanced more often than higher energies; (b) events that fill the slot region are more common at lower energies; (c) enhancements of electrons in the inner zone are more common at lower energies; and (d) even when events do not fully fill the slot region, enhancements at lower energies tend to extend to lower L shells than higher energies. During enhancement events the outer zone extends to lower L shells at lower energies while being confined to higher L shells at higher energies. The inner zone shows the opposite with an outer boundary at higher L shells for lower energies. Both boundaries are nearly straight in log(energy) versus L shell space. At energies below a few 100 keV, radiation belt electron penetration through the slot region into the inner zone is commonplace, but the number and frequency of "slot filling" events decreases with increasing energy. The inner zone is enhanced only at energies that penetrate through the slot. Energy- and L shell-dependent losses (that are consistent with whistler hiss interactions) return the belts to more quiescent conditions.
Collapse
Affiliation(s)
- Geoffrey D Reeves
- Space Science and Applications Group Los Alamos National Laboratory Los Alamos New Mexico USA; The New Mexico Consortium Los Alamos New Mexico USA
| | - Reiner H W Friedel
- Space Science and Applications Group Los Alamos National Laboratory Los Alamos New Mexico USA; The New Mexico Consortium Los Alamos New Mexico USA
| | - Brian A Larsen
- Space Science and Applications Group Los Alamos National Laboratory Los Alamos New Mexico USA; The New Mexico Consortium Los Alamos New Mexico USA
| | - Ruth M Skoug
- Space Science and Applications Group Los Alamos National Laboratory Los Alamos New Mexico USA
| | - Herbert O Funsten
- Space Science and Applications Group Los Alamos National Laboratory Los Alamos New Mexico USA
| | | | | | - Drew L Turner
- The Aerospace Corporation Los Angeles California USA
| | | | - Harlan E Spence
- Institute for the Study of Earth, Oceans, and Space and Department of Physics University of New Hampshire Durham New Hampshire USA
| | | | - Daniel N Baker
- Laboratory for Atmospheric and Space Physics University of Colorado Boulder Boulder Colorado USA
| |
Collapse
|
3
|
Dai L, Wang C, Duan S, He Z, Wygant JR, Cattell CA, Tao X, Su Z, Kletzing C, Baker DN, Li X, Malaspina D, Blake JB, Fennell J, Claudepierre S, Turner DL, Reeves GD, Funsten HO, Spence HE, Angelopoulos V, Fruehauff D, Chen L, Thaller S, Breneman A, Tang X. Near-Earth injection of MeV electrons associated with intense dipolarization electric fields: Van Allen Probes observations. GEOPHYSICAL RESEARCH LETTERS 2015; 42:6170-6179. [PMID: 27656009 PMCID: PMC5014237 DOI: 10.1002/2015gl064955] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 07/15/2015] [Accepted: 07/16/2015] [Indexed: 05/17/2023]
Abstract
Substorms generally inject tens to hundreds of keV electrons, but intense substorm electric fields have been shown to inject MeV electrons as well. An intriguing question is whether such MeVelectron injections can populate the outer radiation belt. Here we present observations of a substorm injection of MeV electrons into the inner magnetosphere. In the premidnight sector at L ∼ 5.5, Van Allen Probes (Radiation Belt Storm Probes)-A observed a large dipolarization electric field (50 mV/m) over ∼40 s and a dispersionless injection of electrons up to ∼3 MeV. Pitch angle observations indicated betatron acceleration of MeV electrons at the dipolarization front. Corresponding signals of MeV electron injection were observed at LANL-GEO, THEMIS-D, and GOES at geosynchronous altitude. Through a series of dipolarizations, the injections increased the MeV electron phase space density by 1 order of magnitude in less than 3 h in the outer radiation belt (L > 4.8). Our observations provide evidence that deep injections can supply significant MeV electrons.
Collapse
Affiliation(s)
- Lei Dai
- State Key Laboratory of Space Weather, National Space Science Center Chinese Academy of Sciences Beijing China; School of Physics and Astronomy University of Minnesota, Twin Cities Minneapolis Minnesota USA
| | - Chi Wang
- State Key Laboratory of Space Weather, National Space Science Center Chinese Academy of Sciences Beijing China
| | - Suping Duan
- State Key Laboratory of Space Weather, National Space Science Center Chinese Academy of Sciences Beijing China
| | - Zhaohai He
- State Key Laboratory of Space Weather, National Space Science Center Chinese Academy of Sciences Beijing China
| | - John R Wygant
- School of Physics and Astronomy University of Minnesota, Twin Cities Minneapolis Minnesota USA
| | - Cynthia A Cattell
- School of Physics and Astronomy University of Minnesota, Twin Cities Minneapolis Minnesota USA
| | - Xin Tao
- Department of Geophysics and Planetary Sciences University of Science and Technology of China Hefei China
| | - Zhenpeng Su
- Department of Geophysics and Planetary Sciences University of Science and Technology of China Hefei China
| | - Craig Kletzing
- Department of Physics and Astronomy University of Iowa Iowa City Iowa USA
| | - Daniel N Baker
- Laboratory for Atmospheric and Space Physics University of Colorado Boulder Boulder Colorado USA
| | - Xinlin Li
- Laboratory for Atmospheric and Space Physics University of Colorado Boulder Boulder Colorado USA
| | - David Malaspina
- Laboratory for Atmospheric and Space Physics University of Colorado Boulder Boulder Colorado USA
| | - J Bernard Blake
- Space Sciences Department The Aerospace Corporation Los Angeles California USA
| | - Joseph Fennell
- Space Sciences Department The Aerospace Corporation Los Angeles California USA
| | - Seth Claudepierre
- Space Sciences Department The Aerospace Corporation Los Angeles California USA
| | - Drew L Turner
- Space Sciences Department The Aerospace Corporation Los Angeles California USA
| | | | | | - Harlan E Spence
- Department of Physics Institute for Earth, Oceans and Space University of New Hampshire Durham New Hampshire USA
| | - Vassilis Angelopoulos
- Department of Earth, Planetary and Space Sciences and Institute of Geophysics and Planetary Physics University of California Los Angeles California USA
| | - Dennis Fruehauff
- Institute of Geophysics and extraterrestrial Physics Braunschweig University of Technology Braunschweig Germany
| | - Lunjin Chen
- Department of Physics University Of Texas at Dallas Richardson Texas USA
| | - Scott Thaller
- School of Physics and Astronomy University of Minnesota, Twin Cities Minneapolis Minnesota USA
| | - Aaron Breneman
- School of Physics and Astronomy University of Minnesota, Twin Cities Minneapolis Minnesota USA
| | - Xiangwei Tang
- School of Physics and Astronomy University of Minnesota, Twin Cities Minneapolis Minnesota USA
| |
Collapse
|
5
|
Liou K, Meng CI, Newell PT, Lui ATY, Reeves GD, Belian RD. Particle injections with auroral expansions. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2000ja003003] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
6
|
Sergeev VA, Shukhtina MA, Rasinkangas R, Korth A, Reeves GD, Singer HJ, Thomsen MF, Vagina LI. Event study of deep energetic particle injections during substorm. ACTA ACUST UNITED AC 1998. [DOI: 10.1029/97ja03686] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|