Harlan Spence, UNH

Title: Progress in Understanding Earth’s Radiation Belts: Recent Results from the NASA Van Allen Probes and the NSF FIREBIRD Missions  (Video)

Abstract: NASA’s Van Allen Probes began its two-year prime science mission phase following its launch into the inner magnetosphere in August 2012. Designed to study and understand radiation belt structure and dynamics “ideally to the point of predictability”, the dual-spacecraft Van Allen Probes mission comprises a comprehensive suite of charged particle and fields measurements needed to achieve closure on critical sciencequestions.  The Radiation Belt Storm Probes – Energetic Particle, Composition, and Thermal Plasma (RBSP-ECT) suite consists of three primary instrument types that collectively provide clean, robust measurements of the electrons and key ions in the inner magnetosphere, with high energy spectral and pitch angle resolution, spanning energy ranges covering the cold/warm plasmasphere populations, the hot ring current populations, the medium-energy electron “seed” population, as well as the core relativistic and ultra-relativistic radiation belt populations.  The Van Allen Probes orbit near the magnetic equator, optimized for probing the source regions of particle acceleration and at a location through which virtually all particles must pass.  However, because the atmospheric loss cone is so small at the magnetic equator, even such an ambitious mission cannot completely explore atmospheric loss process without additional measurements near the atmosphere.  In a complimentary fashion, NSF’s Focused Investigation of Relativistic Electron Burst Intensity Range and Dynamics (FIREBIRD) mission orbits at low altitudes, measuring radiation belt electrons precipitating into the atmosphere with two identically instrumented CubeSats.  FIREBIRD was launched in late January 2015 when it began probing the spatial-temporal variability of radiation belt electron precipitation. In this presentation, we provide a summary of the science accomplishments from the combined RBSP-ECT instrument suite and FIREBIRD missions, with a focus on radiation belt loss processes, particularly to the atmosphere as well as their ultimate impacts.