1. Multi-point observations of dispersionless injection fronts inside geostationary orbit: propagation and structure Authors (preliminary) David Malaspina 1, John Wygant 2, Bob Ergun 1, Allison Jaynes 1, Matina Gkioulidou 3, Sasha Ukhorskiy 3, Geoff Reeves 4, Craig Kletzing 5 [1] CU/LASP [2] U. Minnesota [3] APL [4] Los Alamos [5] U. Iowa Van Allen Probes SWG 23-25 Sept. 2014

2. Dispersionless injection fronts from the Van Allen Probes Propagation: Velocity by propagation delays (e-, E-fields, B-fields) 10 – 30 km/s [L = 5.5 – 6.5] (Reeves et al. 1996) Front deceleration measureable (w/ 3 s/c) estimate dwell time at rad. belt distances help evaluate flow energy conversion efficiency Region of intense time-domain electric field structures travels with injection fronts double layers / steepened whistlers / phase space holes / kinetic Alfvén waves Structure: Time domain electric field structures precede dispersionles injection fronts / persist afterward opportunities for non-adiabatic acceleration indicative of FAC generation? Transient, dispersionless (e-, H+) precursors Substantial structure differences > 350 km (0.06 Re) Direct injections (consistent with previous studies) < 5 MeV e- to rad. belt region < 400 keV O+ into ring current region (~6 events so far w/ both s/c in close proximity) REPT MagEIS HOPE E-wave B-wave |B|

3. Injection Front Measurements in Extended Mission Possible Changes: Favor orbits maximizing time with radial separations > 0.5 L-shell, similar MLT, for midnight/dusk Adjust EFW and/or EMFISIS spectral data coverage to fully duty cycle Implement mode changes when: - Van Allen Probes closely spaced - based on proximity to ERG / MMS Trigger HOPE for electron only / ion only modes Trigger MagEIS burst mode Triggers for EMFISIS / EFW burst captures Directly addresses: Theme 1: injection temporal structure, evolution, effects on radiation belt and ring current Theme 5: Detailed character of microphysical processes that energize radiation belt particles New opportunities: Varied orbital separation More measurement points in region of interest: ERG and MMS New instrument modes to more precisely measure injection front propagation / structure More opportunities to observe storm-time injections in the midnight / dusk sector (only 6 dispersionless injections found so far w/ correct s/c positioning)