Upstream “undisturbed” and locally measured solar wind parameters during the Rosetta mission (2014–2016), averaged over one day. (A) Solar wind He²⁺ flux, noted , from ACE-MEX (blue line), and retrieved from RPC-ICA local measurements at comet 67P (red line). Local RPC-ICA fluxes are shown in black for comparison. (B) Solar wind speed measured by ACE-Mars Express (H⁺, blue line) and by RPC-ICA (He²⁺, red line).