Multipoint Satellite and Ground Observations of the Injection Region
Friday, 18 December 2015
Poster Hall (Moscone South)
Understanding particle energization and transport throughout the magnetotail is fundamental to modeling particle sources and losses in Earth’s inner magnetosphere. Instrumental in studying the energization and transport process, injections are observed as sudden increases in particle fluxes across several energy channels. Where the injection region forms and how it evolves, however, is still unknown. The data thus far have supported two seemingly opposing models for the injection acceleration region: (1) a large-scale, near-Earth (~8-9 RE) region that explosively forms perhaps as a result of current disruption and global dipolarization, which then propagates both earthward and tailward; (2) multiple, localized, transient acceleration episodes that propagate earthward with the dipolarizing flux bundle at fast speeds (~400 km/s) after reconnection, resulting in flux pile-up near Earth with effects then progressing downtail. Our work utilizes both in-situ data as well as ground-based riometers to explore whether the injection region results from a global phenomenon, such as disruption in the cross-tail current leading to global dipolarization, or localized, earthward-traveling dipolarizing flux bundles and fast flows—or possibly both.