Comparison of Ion Temperatures in the Magnetosphere as a Function of the AE Index using TWINS ENA data

Abstract:

The ion temperature in the plasma sheet influences the development of the ring current. Previous studies have considered the effects of geomagnetic storm activity on ion temperatures in the plasma sheet. We present a parametric study on the effects of substorm activity on ion temperatures. More than 3 years of data are sorted using the Auroral Electrojet (AE) index into quiet time (<100.0), moderate activity (100.0<AE<300.0), and high activity (>300.0) and by IMF Bz polarity to create six unique maps. Each of the six temperature maps are calculated using each TWINS spacecraft and then compared. The calculation for determining ion temperatures follows the methods in Scime et al., [2002; 2005] and Keesee et al., [2008; 2011]. We have excluded the near Earth region of ± 3 R_E because our assumptions are not valid in this region of high collisionality. We will discuss observed features, including some that are instrumental artifacts. We will also present preliminary modeling results for comparison using the Space Weather Modeling Framework.