Explosive Magnetotail Activity

Journal Article · 15 May 2019 · Space Science Reviews

DOI: https://doi.org/10.1007/s11214-019-0599-5 · OSTI ID:1567274

Sitnov, Mikhail ^[1]; Birn, Joachim ^[2]; Ferdousi, Banafsheh ^[3]; Gordeev, Evgeny ^[4]; Khotyaintsev, Yuri ^[5]; Merkin, Viacheslav ^[1]; Motoba, Tetsuo ^[1]; Otto, Antonius ^[6]; Panov, Evgeny ^[7]; Pritchett, Philip ^[8]; Pucci, Fulvia ^[9]; Raeder, Joachim ^[10]; Runov, Andrei ^[11]; Sergeev, Victor ^[4]; Velli, Marco ^[3]; Zhou, Xuzhi ^[12]

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1. Johns Hopkins Univ., Baltimore, MD (United States). University Applied Physics Lab.
2. Space Science Inst., Boulder, CO (United States)
3. Univ. of California, Los Angeles, CA (United States)
4. Saint Petersburg State Univ., St. Petersburg (Russia). Earth’s Physics Dept.
5. Swedish Inst. of Space Physics, Uppsala (Sweden)
6. Univ. of Alaska Fairbanks, Fairbanks, AK (United States)
7. Space Research Inst., Austrian Academy of Sciences, Graz (Austria)
8. Univ. of California, Los Angeles, CA (United States). Dept. of Physics and Astronomy
9. National Inst. for Fusion Science, National Inst. of Natural Sciences, Toki (Japan); Princeton Univ., NJ (United States). Princeton Plasma Physics Lab.
10. Univ. of New Hampshire, Durham, NH (United States). Inst. for the Study of Earth, Oceans and Space
11. Univ. of California, Los Angeles, CA (United States). Inst. of Geophysics and Planetary Physics
12. Peking Univ., Beijing (China). School of Earth and Space Sciences

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.

• Research Organization: Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)
• Sponsoring Organization: USDOE
• OSTI ID: 1567274
• Journal Information: Space Science Reviews, Journal Name: Space Science Reviews Journal Issue: 4 Vol. 215; ISSN 0038-6308
• Publisher: SpringerCopyright Statement
• Country of Publication: United States
• Language: English