Depth and cell structure of the solar meridional return flow

Determine the depth and cell structure of the equatorward meridional return flows beneath the solar surface, for which helioseismic observations provide evidence but whose subsurface organization remains uncertain.

Background

The paper identifies surface poleward meridional flows as an important component of the solar dynamo and notes that helioseismic observations suggest the existence of equatorward return flows at depth. However, the available observations do not yet establish how deep these return flows occur or how their circulation cells are organized. Resolving their depth and cell structure would improve constraints on flux-transport and dynamo models, which depend on the subsurface circulation pattern.