On the origin of magnetic fields in the quiet photosphere

We consider the possibility that a substantial fraction of the magnetic fie ld in the quiet photosphere is generated locally by dynamo action associate d with the granular and supergranular flows. The argument is based on recen t advances in the theory of fast dynamos and is supported by large-scale nu merical simulations that show that thermally driven turbulent convection ca n indeed be an efficient source of small-scale, highly intermittent magneti c fields. Some aspects of the resulting magnetic field, such as its strengt h and degree of intermittency, are discussed.