Artificial modification of Earth’s radiation belts by ground-based very-low-frequency (VLF) transmitters

Effects of Hot Protons on the Pitch Angle Scattering of Ring Current Protons by EMIC Waves

“…EMIC waves are known to be generated by the cyclotron instability of anisotropic distribution of ∼10–100 keV ring current protons (e.g., Anderson et al., 1996; Chen et al., 2010; Cornwall, 1965; Meredith et al., 2014; Min et al., 2015; Saikin et al., 2015; Wang et al., 2016; Yue et al., 2019; Zhang et al., 2014). Cyclotron resonant interactions with EMIC waves are recognized to be one of the dominant mechanisms accounting for the rapid precipitation loss of radiation belt electrons (e.g., Aseev et al., 2017; Cao et al., 2020; Kersten et al., 2014; Liu et al., 2012, 2010; Meredith et al., 2003; Ni et al., 2015, 2018; Ni, Zhang, & Gu, 2022; Shprits et al., 2008, 2013, 2016, 2017; Summers et al., 2007; Summers & Thorne, 2003; Thorne & Kennel, 1971; Usanova et al., 2014; Zhang et al., 2016) and ring current protons (e.g., Bortnik et al., 2006; Cao et al., 2013, 2017, 2019; Cornwall et al., 1970; Jordanova et al., 2001; Lyons & Thorne, 1972; Ma et al., 2019; Millan & Thorne, 2007; Ni, Hua, et al., 2022; Usanova, 2021; Usanova et al., 2010; Xiao et al., 2011) into the atmosphere. EMIC waves can also heat thermal electrons and heavy ions (He + and O + ; e.g., Horne & Thorne, 1997; Thorne & Horne, 1997; Zhang et al., 2011; Zhu et al., 2021).…”

Quasi‐Trapped Electron Fluxes Induced by NWC Transmitter and CRAND: Observations and Simulations

“…Pitch angle diffusions induced by wave‐particle interactions are loss mechanisms for trapped electrons but can be sources of quasi‐trapped electrons (e.g., Pham et al., 2017; Tu et al., 2010). Trapped energetic electrons can be scattered into the DLC and become quasi‐trapped induced by various magnetospheric wave modes including chorus waves, plasmaspheric hiss waves, EMIC waves, and man‐made VLF transmitter signals (e.g., Albert et al., 2020; Cao et al., 2017; B. Ni et al., 2014, 2015; 2017, 2021; J. A. J.…”

Radiation Belt Electron Acceleration Driven by Very‐Low‐Frequency Transmitter Waves in Near‐Earth Space

“…Both observational and theoretical analyses have revealed the important role of VLF transmitters in driving electron losses in the near‐Earth space (Abel & Thorne, 1998a, 1998b; Albert et al., 2020; Claudepierre et al., 2020; Graf et al., 2009; Ni et al., 2022; Ross et al., 2019; Selesnick et al., 2013; Starks et al., 2020). A local minimum of electron lifetime at tens to hundreds keV energies at L ∼ 2 due to VLF transmitter waves indicates their importance in electron loss in the near‐Earth space (Abel & Thorne, 1998a, 1998b, 1999; Albert, 1999; Ripoll et al., 2015; Ross et al., 2019).…”