GEM: Quantifying the Effects of Inductive Electric Fields in the Terrestrial Magnetosphere

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

One of the major questions in magnetospheric physics is the issue of how the typical energy of solar wind and ionospheric particles becomes accelerated from energies in the range of a few eVs to energies of hundreds of keVs that are typically observed in the near Earth space. The need for this acceleration to occur implies the production within the magnetosphere of a potential that is applied to the particles moving along the geomagnetic flux tube. The challenging task in modeling this potential lies in producing an estimate of the inductive effects arising from the presence of a time-dependent magnetic field as compared with the potential that is a part of the plasma convection process across the geotail. The extent of this partition remains an unresolved question in geospace research. This award would model the physics of this acceleration mechanism to determine the magnitude of the inductive electric field caused by the temporal variation of the magnetic field as compared with the magnitude of the potential electric field source. The award will have the consequence that the relative contributions of potential and inductive electric field driven convection resulting in the development of the storm time ring current will for certain cases become quantified. A young woman scientist just beginning her faculty appointment as an assistant professor will be supported with this award. The PI would use a theoretical model to calculate the inductive component of the electric field. Knowledge of the electromagnetic fields is required to model accurately the acceleration processes and the transport of plasma within the inner magnetosphere. This approach would be applied to several preselected real event case studies as well as simplified and idealized input simulations. The former path would allow detailed data-model comparisons to determine which physical process dominates the dynamics of the magnetosphere. The latter path would provide insight into the systematic influences of various solar wind parameters. Knowledge of the relative contribution of potential versus inductive electric fields at intensifying the hot ion population would be used to study the connection between the macro-scale dynamics and micro-scale processes that govern this region and solidify comprehension of the physical processes controlling magnetosphere dynamics.