Progenitor simulation, Case D3, from Brown et al. (2010). (a) Radial velocity in a Mollweide projection near the top of the computational domain ( r = 0.953  R, t = 2 yr, color table saturation ±70 m s ⁻¹, yellow/orange upflow, blue/black downflow). (b) Angular velocity Ω/2π, averaged over 1200 days (7.8–11.3 yr, saturation 1140–1320 nHz, white/red fast, blue/black slow). (c) Mean toroidal magnetic field B _ϕ averaged over longitude and time (15 day average near t = 2 yr, saturation ±8 kG, red positive, blue negative). (d) B _ϕ in the mid convection zone ( r = 0.84  R) vs. latitude and time (colors as in (c), saturation ±4 kG).