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IBEX Energetic Particles From the Shock 11 April 2007. Stephen A. Fuselier Space Physics Department LMATC. Agenda. Energetic particles from the shock – IBEX background Examples from Geotail. Example “IBEX” Orbit 1: 30 R E Apogee. Selected an event where the Geotail spacecraft was
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IBEX Energetic Particles From the Shock11 April 2007 Stephen A. Fuselier Space Physics Department LMATC S. A. Fuselier
Agenda • Energetic particles from the shock – IBEX background • Examples from Geotail S. A. Fuselier
Example “IBEX” Orbit 1: 30 RE Apogee Selected an event where the Geotail spacecraft was near apogee and nearly in front of the Earth Use this event to investigate how well the bow shock model determines the energetic ion environment In the model, the bow shock and magnetopause locations are adjusted for the solar wind dynamic pressure S. A. Fuselier
Energetic Ions and Bn – Good correlation Top panel: Bn versus time Bottom panel – 9, 22, 55 keV proton flux Typically, when Bn drops below 25°, the fluxes saturate Above ~45°, the fluxes decrease to background S. A. Fuselier
Bow Shock Connections Traced Back From the Spacecraft Position X’s show the location of the “straight” field lines traced back to the bow shock location The field lines are determined from the Geotail magnetic field data (instead of the upstream monitor data) S. A. Fuselier
Example “IBEX” Orbit 2: “Outbound” Selected an event where the Geotail spacecraft was on an outbound trajectory and nearly in front of the Earth S. A. Fuselier
Energetic Ions and Bn – Good correlation Top panel: Bn versus time Bottom panel – 9, 22, 55 keV proton flux Absolute flux levels do not correlate well with Bn, even within the same event (Flux is a function of distance to the Earth and other parameters) S. A. Fuselier
Bow Shock Connections Traced Back From the Spacecraft Position X’s show the location of the “straight” field lines traced back to the bow shock location The field lines are determined from the Geotail magnetic field data (instead of the upstream monitor data) S. A. Fuselier
Conclusions • Accurately predict connection to the bow shock using a model bow shock • Need magnetic field data (from an upstream monitor) • Modify the shock location using the solar wind dynamic pressure • Code exists • Actual bow shock flux varies by more than an order of magnitude over intervals when the spacecraft is connected to the shock • Channel D? S. A. Fuselier