Current reconstruction for the two models with heating considered in Fig. 2. Top: evolution of the best-fitting power-law indexes, β (black, indicating the steepness of the conductivity profile σ(r) ∼ r^−β), at shallow (p ∼ 10² bar, solid), intermediate (p ∼ 10⁴ bar, dashed), and deep (p ∼ 10⁶–10⁷ bar, dots) layers and the corresponding local indexes, α, of the induced current profile, Eq. (14), for l = 2 (cyan) and l = 10 (green). Middle: radial profiles of the induced currents for the same model at ages of t ≃ 0.4 (dots), 1.1 (dashes), and 5 Gyr (solid lines) for a purely dipolar case, (only j₂, 0, blue and red) or multipolar, with a flat magnetic spectrum at dynamo surface from l = 2 to l = 10 (cyan and golden). Bottom: corresponding Ohmic heating rate profiles.