Plasma Physics of the Subauroral Space Weather
Technical Report,01 Oct 2013,30 Sep 2015
Air Force Research Laboratory, Space Vehicles Directorate Kirtland AFB United States
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This research addresses basic plasma processes that control the dynamics of the perturbed inner magnetospheresubauroral ionosphere termed the subauroral geospace. Our observations demonstrated the need of a dramatic re-evaluation of our understanding of the development of the subauroral disturbances. Using multispacecraft observations near the magnetic equator and in the ionosphere, we specified their features and space weather effects. Near substorm onsets, highly irregular subauroral regions create strong scintillations ofUHF and GPS L1 band signals. Irregular structures in the plasmasphere guide VLF whistler waves thereby facilitating precipitation of radiation belt electrons. Our study shows that the conventional 30-year paradigm is in serious error and so puts forward a novel concept of a turbulent plasmaspheric boundary layer formed in the evening sector where the plasmasphere short-circuits reconnection-injected hot plasma jets. To describe UHFGPS L1 band irregularities, a numerical, first-principle hybrid model of interchange and Kelvin-Helmholtzin stabilities in the equatorial and mid latitude ionosphere has been developed. It includes finite Larmor radius effects in low ionosphere and high plasma sheet beta plasmas with velocity shear to go beyond the state-of-the-art fluid models, e.g. AFRLPBMOD.