8 April 2013 to 3 May 2013
Nordita
Europe/Stockholm timezone

Meridional circulation in solar and stellar convection zones

Not scheduled
132:028 (Nordita)

132:028

Nordita

Talk

Speaker

Mark Miesch (High Altitude Observatory, National Center for Atmospheric Research, Boulder)

Description

The mean (axisymmetric) circulation in the meridional plane plays a key role in many recent solar and stellar dynamo models. This is particularly the case in so-called "Flux-Transport" dynamo models in which the meridional circulation regulates the duration of magnetic activity cycles. Many of these models are kinematic in nature so the meridional circulation must be prescribed. Yet, there is little guidance from solar and stellar observations on what the subsurface circulation actually is. Here we present constraints on the meridional circulation in the Sun and solar-like stars obtained from global convection simulations as well as careful scrutinty of helioseismic inversions within the context of the prevailing dynamical balances. We find two dintinct mean flow regimes, delineated by the Rossby number. Fast rotators exhibit multi-celled circulation profiles and solar-like rotation profiles while slow rotators exhibit anti-solar rotation profiles and single-cell (per hemisphere) circulation profiles. We identify the dynamical processes responsible for these two regimes and we discuss the implications with regard to mean flows and dynamo cycles in the Sun and stars.

Primary authors

Mark Miesch (High Altitude Observatory, National Center for Atmospheric Research, Boulder) Nicholas Featherstone (High Altitude Observatory, National Center for Atmospheric Research, Boulder)

Presentation materials

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