Magnetotail dipolarization fronts and particle acceleration: A review

Electron‐Scale Measurements of Antidipolarization Front

“…Reconnection fronts, the leading edge of the reconfigured magnetic field after reconnection, expand both earthward and tailward from the reconnection site. On the earthward side, the highly stretched tail magnetic field becomes rapidly more dipolar, hence the earthward-moving reconnection fronts are also called dipolarization fronts (DFs) (Angelopoulos et al, 2013;H. S. Fu, Grigorenko, et al, 2020;Runov et al, 2011).…”

“…Reconnection fronts, the leading edge of the reconfigured magnetic field after reconnection, expand both earthward and tailward from the reconnection site. On the earthward side, the highly stretched tail magnetic field becomes rapidly more dipolar, hence the earthward‐moving reconnection fronts are also called dipolarization fronts (DFs) (Angelopoulos et al., 2013; H. S. Fu, Grigorenko, et al., 2020; H. S. Fu, Khotyaintsev, et al., 2013; Runov et al., 2011). A DF is characterized by rapid increase of the magnetic field (B z ) and decrease of plasma density (H. S. Fu, Khotyaintsev, Vaivads, André, & Huang, 2012b; Huang, Fu, Vaivads, et al., 2015; R. Nakamura et al., 2002; Runov et al., 2011; Schmid et al., 2011), which is usually embedded in a bursty bulk flow (Angelopoulos et al., 1992; J.…”

Electron Pitch‐Angle Distribution in Earth's Magnetotail: Pancake, Cigar, Isotropy, Butterfly, and Rolling‐Pin

“…The earthward transport of mass and magnetic flux, usually accompanied by intermittent coherent structures, such as bursty bulk flows (BBF) (e.g., Angelopoulos et al, 1992; Cao et al, 2006, , 2013) and dipolarization fronts (e.g., Fu, Khotyaintsev, Vaivads, André, & Huang, 2012a, 2012b; Fu, Cao, et al, 2013; Liu et al, 2013; Liu, Fu, Xu, et al, 2018; Liu, Fu, Vaivads, et al, 2018; Nakamura et al, 2002; Runov et al, 2009; Sergeev et al, 2009; Yao et al, 2017), ultimately provides sufficient energy for the auroral substorms (e.g., Angelopoulos et al, 2008; Liu et al, 2014; Liu, Fu, Xu, et al, 2018; Yao et al, 2012). One typical signature associated with such energy transport is the increase of suprathermal (from tens to hundreds of keV) electron flux in the terrestrial magnetotail (e.g., Asano et al, 2010; Kronberg et al, 2017; Pan et al, 2014; Turner et al, 2016), which results from local acceleration at reconnection region (e.g., Chen, Fu, Zhang, et al, ; Drake et al, 2006; Egedal et al, 2010; Hoshino et al, 2001; Huang, Vaivads, et al, 2012; Fu, Xu, et al, 2019; Øieroset et al, 2002; Vaivads et al, 2011; Fu et al, ) and dipolarization fronts (DFs) (e.g., Ashour‐Abdalla et al, 2011; Birn et al, 2014; Duan et al, 2014; Fu et al, 2011; Fu, Khotyaintsev, et al, 2013; Fu, Grigorenko, et al, 2020; Gabrielse et al, 2016; Huang, Zhou, et al, 2012; Khotyaintsev et al, 2011; Liu, Fu, Xu, Wang, et al, 2017; Liu, Fu, Cao, Xu, et al, 2017; Liu, Liu, Xu, et al, 2018; Liu et al, 2019; Lu et al, 2016; Pan et al, 2012; Runov et al, 2013; Wu et al, 201...…”

First Observation of Magnetic Flux Rope Inside Electron Diffusion Region

“…The EDR is embedded in the ion diffusion region (IDR; Fu et al., 2019a; Øieroset et al., 2001) because of different motions between ions and electrons. Magnetic reconnection can lead to reconfiguration of magnetic field topology (Chen et al., 2019a; Fu et al., 2019b, 2020a) and formation of many structures, such as reconnection fronts (Fu et al., 2013b, 2019c, 2020b; Liu et al., 2018), magnetic nulls (Chen et al., 2018; Fu et al., 2020a), and magnetic flux ropes (MFRs; also called magnetic islands or plasmoids; Chen et al., 2019b, 2019c; Daughton et al., 2011; Drake et al., 2006a; Deng et al., 2004; Eastwood et al., 2016; Fu et al., 2016; Huang et al., 2016a; Slavin et al., 2003), which, in turn, play crucial roles in magnetic reconnection (Daughton et al., 2011; Huang et al., 2012; Oka et al., 2010; Wang et al., 2015).…”