Composition Changes in the Solar Wind and in the Dayside Magnetosphere

There are two primary pathways by which solar wind becomes part of Earth's ring current. When the IMF is southward, reconnection occurs at low latitudes and solar wind ions are circulated throughout the magnetosphere via the Dungey cycle, convecting back to the dayside as part of the ring current. When the IMF is northward, reconnection occurs poleward of the cusp and solar wind enters the magnetosphere at high latitudes. Circulation still occurs under these conditions, however. Injected solar wind enters the magnetotail plasma sheet, is driven Earthward by tail reconnection, and ultimately becomes part of the ring current. Since the transport processes of solar wind material are different for northward and southward IMF, there is no reason to assume that the transport timescales should be the same. Using data from the Advanced Composition Explorer (ACE), Magnetospheric Multiscale (MMS), and WIND spacecraft, we compare transport times under different IMF orientations for a select number of solar wind events with enhanced He⁺⁺ concentrations. We do so by identifying large increases in the solar wind He⁺⁺/H⁺ density ratio and then measuring how long it takes the dayside ring current to reflects those same composition changes.