List of Footnotes

1 This value is used by Jahn and Schmidt, however, we note that their quiet Sun value corresponds to an average across the solar disk. The effective (radiation) temperature of the quiet Sun at disk center amounts to 6060 K according to Neckel and Labs (1984).
2 At that time Deinzer was a student of Biermann.
3 T(u) ≈ 4000 K, T(QS ) ≈ 6060 K: (T(u)∕T(QS ))4 ≈ 19%
4 Note that Ichimoto-san introduced these as ‘penumbral twists’, but from comparing opposite sides of the penumbra he concluded that they cannot be a twist of magnetic field lines.
5 Line profiles that produce a white patch in the Ichimotogram look like the profile in right panel of Figure 4View Image. This figure is discussed below in the context of why the flow is magnetized (last paragraph of this subsection).
6 The interpretation of Sánchez Almeida and Ichimoto (2009) also involves Doppler shifted components of opposite polarity, but is embedded in a micro-structured magnetic atmosphere (Sánchez Almeida, 1997).
7 For the HMI data we thank NASA/SDO and the AIA, EVE, and HMI science teams.