Evolution of various atmospheric parameters (B_SIR, T, γ, v_LOS, the optical depth, v_mac, and ρ) returned by the S1 (red lines) and S2 (blue lines) inversion schemes for the full time series at appropriate optical depths for Pixel 15. Bottom right panel: normalised χ² fits for both inversion schemes, displaying that neither appears to fit these spectra significantly better than the other. The evolution of B_SFA is also overlaid in the top left panel (black line). It should be noted that B_SFA and the LOS magnetic field strength returned by S1 match well, whereas the LOS magnetic field strength does not change over time in the S2 inversions. All inverted parameters are plotted at log τ₅₀₀₀ = −0.5, except for T, which is plotted at log τ₅₀₀₀ = 0.5.