Investigation of O+ and H+ Properties During the Evolution of Two Intense Geomagnetic Storms: Implications for Solar Wind Conditions' Effect on the Abundance of Ionospheric vs. Solar Wind Plasma Source in the Inner Magnetosphere.

Understanding the accumulation, transport, and energization of the O+ ions in the plasma sheet and inner magnetosphere is essential for magnetospheric dynamics, yet, just how O+ ions populate the magnetosphere during a geomagnetic storm, remains a compelling open question. There are several paths that O+ ions of various energies can follow after a storm sudden commencement, and the response time of their accumulation in different regions of the magnetosphere, associated with each path, differ. Using Van Allen Probes, MMS and Arase data, we investigate the timeline of accumulation of O+ ions ranging from eV to 10s of keV energies in the inner magnetosphere during the progress of two geomagnetic storms with similar Dst index but distinctly different solar wind conditions. We investigate the progression of O+ temperature, number density and energy density at different L shells. We also examine the O+/H+ ratios of these properties throughout the duration of the storms, in order to differentiate between processes that affect the enhancement of both species vs. those that are unique to the accumulation of ionospheric O+, and how those processes differ based on the solar wind conditions.