TY - JOUR

T1 - Explosive Magnetotail Activity

AU - Sitnov, Mikhail

AU - Birn, Joachim

AU - Ferdousi, Banafsheh

AU - Gordeev, Evgeny

AU - Khotyaintsev, Yuri

AU - Merkin, Viacheslav

AU - Motoba, Tetsuo

AU - Otto, Antonius

AU - Panov, Evgeny

AU - Pritchett, Philip

AU - Pucci, Fulvia

AU - Raeder, Joachim

AU - Runov, Andrei

AU - Sergeev, Victor

AU - Velli, Marco

AU - Zhou, Xuzhi

PY - 2019/6/1

Y1 - 2019/6/1

N2 - 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.

AB - 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.

KW - Auroral beads/rays

KW - B hump

KW - Ballooning/interchange instability

KW - Bursty bulk flows

KW - Current sheet thinning

KW - Dipolarization fronts

KW - Flapping motions

KW - Flux tube oscillations

KW - Laboratory reconnection experiments

KW - Magnetic reconnection

KW - Magnetotail

KW - Particle acceleration

KW - Plasma micro-instabilities

KW - Supra-arcade downflows

KW - Tearing instability

KW - B z hump

UR - http://www.scopus.com/inward/record.url?scp=85065928489&partnerID=8YFLogxK

UR - http://www.mendeley.com/research/explosive-magnetotail-activity

U2 - 10.1007/s11214-019-0599-5

DO - 10.1007/s11214-019-0599-5

M3 - Review article

C2 - 31178609

AN - SCOPUS:85065928489

VL - 215

JO - Space Science Reviews

JF - Space Science Reviews

SN - 0038-6308

IS - 4

M1 - 31

ER -