Abundance variations in corotating interaction regions over two solar cycles

Abstract:

Corotating interaction regions (CIRs) have been shown to affect magnetospheric storms [e.g., Richardson et al., 2006; Turner et al., 2006], as well as ionosphere/thermosphere densities, winds, and compositions [e.g., Chen et al., 2014]. Previous studies have shown that the suprathermal ion composition associated with CIRs had a solar cycle variation during solar cycle 23 [Mason et al., 2012; Filwett et al., 2017]. However, it is unclear if this variation will be the same for solar cycle 24, or whether the suprathermal ion composition associated CIRs have any longer-term modulation. Using 20 years of ACE observations, we will present a comparison of the suprathermal ion compositions for solar cycle 23 and solar cycle 24, as well as investigating longitudinal widths and variations by comparing ACE to STEREO observations. This will provide further insight into the compositional variations and dynamics associated with CIRs at different points in a solar cycle, as well as reveal how well previous solar cycles can serve as estimates for future cycles.