Comparison between observed and modeled TEC at comet 67P during the entire Rosetta mission operation period. In the top two panels, the red points show the diurnally averaged TEC values obtained from actual observation,while the blue and green points correspond to the model TEC values for ion bulk speeds of 500 and 900 m s⁻¹, respectively. Top panel: the modeled TEC values correspond to a pure H₂O coma, while they correspond to a pure CO₂ coma in thesecond panel from the top. Third panel from the top: corrected EUV fluxes incident on the comet. Bottom panel: variations of r_h (blue, legend on the left) and r_c (red, legend on the right).