Top: TSI variations reconstructed using different models employing the same Rome/PSPT Ca II K data. The shaded surfaces show the range of reconstructions when using ACRIM, ROB, and PMOD TSI composites to set the free parameters of the models (except for RIM). All series were offset to match the value of the Montillet et al. (2022) TSI composite over 2009 (marked with a horizontal line). Bottom: Difference between the TSI reconstructed with the various models and the Montillet et al. (2022) TSI composite. The right panel shows the histogram of the residuals in bins of 0.05 Wm⁻². Shown are 3-month running mean values, while the numbers in each panel give the linear coefficient (R) and RMS differences in Wm⁻² between the models and the Montillet et al. (2022) TSI composite series for monthly values. The running means are computed only over the common days in all series. The horizontal line denotes differences of 0 Wm⁻². The numbers in the lower part of the figure denote the conventional cycle numbering.