Toroidal magnetic field generation and loss associated with surface magnetic fields: The orange points show the rate at which net azithmuthally averaged subsurface toroidal magnetic flux in the northern hemisphere, ⟨b_ϕ⟩, is generated by the poloidal field threading through the solar photosphere. For ϵ Eridani and 61 Cygni A, error bars for the individual measuremnts were calculated using the closely spaced (in time) maps as discussed in the text. We comment that we get similar values of the errors for these two stars if we assume the difference between the fits and the measurements. The green points show the rate at which the net toroidal axisymmetric field in the northern hemisphere is lost through the surface due to flux emergence. The solid curve shows the fits, and the dashed line shows the long-period component of the fit for ϵ Eridani. Top panel: the results obtained using the relatively high resolution images of the Sun, the second row the reduced resolution Sun (ℓ ≤ 3), the third row 61 Cygni A, and the bottom rowϵ Eridani.