Dependence of  ⟨  | ω_y |  ⟩  (top plots) and of different terms of the vorticity equation (bottom plots) on time at different heights in the domain. The first column corresponds to the upper photosphere (500   km above the approximate visible solar surface level), the second column is the visible surface level, and the third column corresponds to the convection zone (650   km below the visible surface level).