Van Allen Probes Observations of the Plasmasphere and Radiation Belts

Wednesday, 17 December 2014: 2:40 PM
Jerry Goldstein1,2, Jörg-Micha Jahn1,2, Sebastian De Pascuale3, Craig Kletzing3, William S Kurth3, Kevin James Genestreti1,2, Ruth M Skoug4, Brian Larsen4, Lynn M Kistler5, Christopher Mouikis5, Harlan E. Spence5, Geoffrey D Reeves4, Daniel N. Baker6 and J Bernard Blake7, (1)Southwest Research Inst, San Antonio, TX, United States, (2)University of Texas at San Antonio, San Antonio, TX, United States, (3)Univ. of Iowa, Iowa City, IA, United States, (4)Los Alamos Natl Lab, Los Alamos, NM, United States, (5)University of New Hampshire, Durham, NH, United States, (6)University of Colorado, Laboratory for Atmospheric and Space Physics, Boulder, CO, United States, (7)The Aerospace Corporation, Los Angeles, CA, United States
Van Allen Probes (RBSP) observations during 15-20 January 2013 are the basis of this study of the spatial relationship between the plasmasphere and radiation belts, and its influence on energy dependent lifetimes of energetic electrons. We use a convection-driven plasmapause test particle (PTP) simulation to provide contextual information for in situ measurements by RBSP during 15-20 January 2013, and find that the model reproduces the observed plasmapause radial locations to within 0.40 Earth radii (RE). We use analysis of the RBSP data to examine the radial structure of both the plasmasphere and radiation belts for the selected 5-day period, which includes a moderate geomagnetic disturbance on 17 January. RBSP observed three belts (inner, outer, and storage ring) prior to the 17 January disturbance, and two belts (inner and outer) afterward. The plasmapause aligns with the outermost belt. We examine the energy dependence of the radial structure and decay lifetimes of energetic electrons, both inside and outside the plasmasphere.