Data-Model Comparisons of Plasma Sheet Ion Temperatures during Moderate Geomagnetic Storms
Wednesday, 17 December 2014
Ion heating occurs during geomagnetic storms as a result of many physical processes, including magnetic reconnection and adiabatic heating. Ion temperatures calculated from TWINS energetic neutral atom (ENA) data provide a global view of regions of heated ions in the plasma sheet. Two storms of similar, moderate magnitude are analyzed, a coronal mass ejection (CME)-driven storm that occurred on 26 September 2011 and a high speed stream (HSS)-driven storm on 13 October 2012. We present a comparison of the ion temperatures during the storms to patterns observed in a superposed epoch analysis of ion temperatures [Keesee et al., 2013] and compare the October storm to a previously analyzed HSS-driven storm [Keesee et al., 2012]. We also present a comparison of observed ion temperatures to those calculated from a simulation of each storm using the Space Weather Modeling Framework, including the BATS-R-US MHD model coupled with the HEIDI inner magnetosphere model.