<<View 2021 THEMIS Nuggets

Toshi Nishimura , January 2022
Space-Ground Observations of Dynamics of Substorm Onset Beads

We determine what structures in the near-Earth plasma sheet are associated with substorm onset beads: what are the magnetotail counterpart of the duskward and dawnward propagation of beads using two conjunction events between the THEMIS satellites and all-sky imagers (ASIs). Read more.

Sam Califf , January 2022
Multi-Event Study on the Connection Between Subauroral Polarization Streams and Deep Energetic Particle Injections in the Inner Magnetosphere

Subauroral polarization streams (SAPS) are a common magnetosphere-ionosphere coupling phenomena that produce strong radial electric fields in the post-dusk sector, which causes asymmetry in the large-scale electric field in the inner magnetosphere. This paper explores the relationship between SAPS and the differential response of 100s keV electrons and protons using Van Allen Probes observations. Read more.

Andreas Keiling, February 2022
Statistical Properties of 102 SPA Events

The magnetosphere tends to show certain, repeatable behaviors, called magnetospheric response modes,that represent manifestations of large energy transport and conversion in the global magnetospheric-ionospheric system. We provide statistics on a ~1-hr periodic response mode, which we term "short-period activation mode" (SPA mode). Read more.

Maria Usanova, March 2022
Electron energization by high-amplitude turbulent electric fields: a source of the outer radiation belt

Electron energization by high-amplitude turbulent electric fields in the nightside magnetosphere is investigated using data from MMS and THEMIS spacecraft. Read more.

M. Fraz Bashir, May 2022
Hot plasma effects on electron resonant scattering by electromagnetic ion cyclotron waves

This paper provides a generic hot plasma model which agrees well with the exact numerical solution and highlights the importance of hot plasma effects on the relativistic electron scattering by EMIC waves for a wide range of plasma parameters. Read more.

Boyi Wang, June 2022
The geoeffectiveness of solar wind current sheets and its modulation by foreshock ions

The dynamic pressure enhancements that are generated by the solar wind bifurcated current sheets are geoeffective. The foreshock ion modulations, which are expected to occur frequently inside the current sheets due to their magnetic field variations, can magnify that geoeffectiveness by creating more perturbations. Read more.

Terry Z. Liu, June 2022
Statistical study of favorable foreshock ion properties for the formation of hot flow anomalies and foreshock bubbles

Through a statistical study using THEMIS and MMS observations, we determined the foreshock ion properties that favor the formation of hot flow anomalies and foreshock bubbles, two types of foreshock transients with the most significant disturbances. Our results enhance our understanding of their formation mechanism and support future establishment of their predictive models. Read more.

Yangyang Shen, July 2022
Tens to Hundreds of keV Electron Precipitation Driven by Kinetic Alfvén Waves During an Electron Injection

Kinetic Alfven waves have been previously observed to be ubiquitously associated with magnetospheric electron injections but have not been considered as an important driver for precipitation of injection electrons with energies of tens to hundreds of keV. Combining ELFIN-MMS observations and numerical simulations, this study provides evidence of energetic electron precipitation driven by kinetic Alfvén waves. Read more.

J. M. Weygand, September 2022
Magnetosphere-Ionosphere Coupling Between North-South Propagating Streamers and High-Speed Earthward Flows

In our study we not only demonstrate that the magnetosphere-ionosphere streamer current system is consistent with the Kauristie et al., [1996] model but we also show the development of the current system and determine if the upward current leg equals in magnitude the downward current portion. Read more.

Jiang Liu, October 2022
The Occurrence of Embedded Region 1 and 2 Currents Depends on Geomagnetic Activity Level

Earth’s magnetosphere is coupled to its ionosphere by electric currents of different scales flowing along magnetic fields (field-aligned currents, or FACs), which are the manifestations of the motion and stress in the magnetosphere-ionosphere (M-I) system. Read more.

Please send comments/suggestions to
Emmanuel Masongsong / emasongsong @ igpp.ucla.edu