Abstract
The study of laminar flows with simple streamlines in conducting fluids that might support kinematic dynamo action has a long history. Early successful examples include the Gailitis (Citation1970) dynamo, which has two meridional rolls. We show here that a single meridional roll, considered as a limit of a modified Gailitis-like dynamo, can also support kinematic dynamo action in a deep spherical shell. This flow has a claim to be the simplest such flow possible.
Acknowledgements
The author is grateful to Dr J.-F. Pinton for bringing the papers of Gailitis (Citation1993, 1995) to his attention. Leon Mestel is thanked for comments on a preliminary version of the text. Constructive comments by the referees (D. Gubbins and F. Plunian) improved the presentation.