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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.
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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
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