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Andrews University Press 2026 Booklist
No full texthttps://digitalcommons.andrews.edu/biblical-studies-books/1013/thumbnail.jp
Electron dynamics within dispersive scale Alfvénic field-line resonances embedded within substorm auroral beads
No full textRecent Cluster satellite observations have illustrated that substorm auroral bead formation and currents are associated with the presence of dispersive scale standing Alfvén waves, which are also known as kinetic scale field line resonances (KFLRs) or kinetic Alfvén eigenmodes. In this work, the properties of these waves are further examined using simulations of a gyrofluid-kinetic electron model in conjunction with the Cluster observations at mid-latitudes and Defense Meteorological Satellite Program satellite observations at high-latitudes. These simulations incorporate, for the first time, the effects of both hot magnetospheric and cold ionospheric electron populations within the multi-period evolution of KFLRs. The simulation results demonstrate consistent characteristics with the observed energized electron distributions both at mid- and high-latitudes. Tracing of the energized particle evolution shows that electrons can effectively interact with the wave all along the field line. Quantified energy conversion rates (as determined from (Formula presented.)) show that significant wave energy dissipation occurs at all latitudes with a maximum occurring in the vicinity of the peak in the profile of the magnetic field to density ratio (Formula presented.). Additionally, even though dispersive effects lead to the propagation of wave energy across field lines, the particle energization leads to rapid damping of the resonant system in only a few Alfvén periods
Propagation of EMIC waves from Shabansky orbits in the dayside magnetosphere
No full textWe explore the characteristics of EMIC waves generated in a non-dipole, compressed magnetic field at the minimum of the magnetic field. We conducted 2D full-wave simulations using the Petra-M code, focusing on a compressed magnetic field in the outer dayside magnetosphere for a range of L values (Formula presented.). By comparing the simulation results with MMS observations, we aim to understand how the observed wave characteristics are affected by a shifting source region across different L-shells. Our findings indicate that the direction of the Poynting vector systematically changes depending on the local source location of the wave, which is consistent with the observations. EMIC waves propagate along the magnetic field line and reach both the northern and southern hemispheres; however, there is a notable difference in the power of EMIC waves between the two hemispheres, indicating seasonal asymmetries in their occurrence
