Magnetosphere-Ionosphere Coupling During the June 22-24, 2015 Magnetic Storm
Thursday, 17 December 2015: 17:21
2016 (Moscone West)
The magnetic storm that commenced on June 22, 2015 was one of the largest storms in the current solar cycle. During this event, ionospheric density measurements from the Floating Potential Measurement Unit (FPMU) on board the International Space Station (ISS) show dramatic depletions in the post-sunset (nighttime) local time sector at equatorial latitudes starting in the main phase of the storm and persisting on several subsequent orbits. Near the same time, the Magnetospheric Multiscale Mission (MMS) Fast Plasma Investigation (FPI) instrument suite data show ion and electron particle flux dropouts coincident in time with the density depletions seen in the ISS data. Both phenomena seem to follow northward turnings of the interplanetary magnetic field (IMF) z-component. We present simulations of this event with the SAMI3-RCM numerical model, which is a coupled ionosphere-magnetosphere model with self-consistent large-scale electrodynamics. We will investigate the role of transient changes in the global convection electric field driven by variations in the IMF Bz in connection with observations of the ionospheric depletions. Simulation results will be compared to the ISS FPMU densities, AMPERE Birkeland currents, DMSP ion drift velocities, MMS FPI particle data, as well as the location of the auroral oval and other available multi-instrument observations, in an attempt to understand the details of magnetosphere-ionosphere coupling during this event and characterize the fidelity of the simulation electrodynamic inputs to the ionosphere model.