Is there a phase constraint for solar dynamo models?

Abstract

The spatio-temporal relationship between the sign of the observed radial component of the magnetic field at the solar surface and the sign of the toroidal field as inferred from Hale's polarity rules for sunspots is usually interpreted as signifying the phase relation between the poloidal and the toroidal magnetic field components involved in the solar dynamo process. This has been taken as a constraint for models of the solar dynamo. This note draws attention to the fact that the observed phase relation is naturally and inevitably produced by the emergence of tilted bipolar regions and flux transport through surface flows, without any necessity of recourse to the dynamo process. Consequently, there is no constraint on dynamo models resulting from the observed phase relation.