High Beta Plasmas and Their Link To Earthbound Flux Bundle ULF Pulsations

This paper presents results of a case study where ULF pulsations were observed during a high beta plasma event on May 1st, 2013. Particle fluxes were compared with the oscillations in the magnetic field data, and anti-phase behavior was observed. Data from this event suggests that these pulsations were created by a mirror instability, since it was during a high beta time and there was sufficient anisotropy in the plasma pressure. This event is compelling due to the presence of an inbound dipolarizing flux bundle during the same orbit, where another mirror-like configuration is observed. Interestingly enough, this second mirror configuration does not have the satisfied criteria. It is speculated that this mirror configuration was propagated into the inner magnetosphere by the movement of the dipolarization front.