Speaker
Prof.
Ian Mann
(University of Alberta)
Description
We will present an example of unusual long-lasting EMIC wave event from October 11, 2012 which occurred in the recovery of a moderate geomagnetic storm (with minimum Dst=-111 nT on October 9, 2012). The wave activity spanned the interval of almost 24 hours MLT and was detected at multiple CARISMA magnetometer stations. During the event, the Van Allen Probe B had a beautiful conjunction with the ground stations and also observed EMIC waves in the local morning sector on a footprint at L~4. In addition, the NOAA POES satellite observed precipitation of energetic (E=30-800 keV) protons at the LEO orbit above the region of EMIC wave activity seen on the ground. Interestingly, despite the fact that intense EMIC waves were present in the inner duskside magnetosphere where they are believed to interact with energetic electrons, neither the Van Allen Probes nor NOAA POES show signatures of MeV electron flux reduction or precipitation, respectively, during that interval. We investigate the potential explanations for not only the excitation of large amplitude EMIC waves across a broad range of local times, but also examine the potential reasons for their apparent inability to effect loss of MeV electrons from the outer radiation belt – specifically including the effects of cold plasma density and the location of the plasmapause on the EMIC-MeV electron resonance conditions.
The research leading to these results has received funding from the European Community’s Seventh Framework Programme (FP7–SPACE–2010–1) under grant agreement n. 284520 for the MAARBLE (Monitoring, Analyzing and Assessing Radiation Belt Energization and Loss) collaborative research project.
Primary author
M. E. Usanova
(U. Alberta)
