Longitudinal magnetic field B_ℓ (top panel), small-scale magnetic field <B> (middle panel) and temperature variations dT (bottom panel) of AU Mic (red dots), with the QP GPR fit to the data (solid cyan line) and corresponding 68% confidence intervals (dotted cyan lines). The residuals, shown in the lower plot of each panel, yield rms values of 7.2 G, 0.038 kG and 0.96 K (${\chi }_{\mathrm{r}}^2$ = 2.3, 0.98 and 0.60, respectively). A zoom on the 2023 and 2024 data is shown in Figs. B.1 and B.2.