Simple laminar dynamos: from two rolls to one.

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 (1970) 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. [ABSTRACT FROM AUTHOR]