Turbulent transport coefficients measured from stellar convective dynamos

January 05, 2018

Turbulent effects play an important role in the magnetic generation of the Sun and stars. Unfortunately, at the moment observation are not able to reveal these effects. On way to understand how these turbulent effects can generate magnetic field via dynamo mechanisms is to study global 3 dimensional magnetohydrodynamic simulation of the Sun and stars... 

Turbulent effects play an important role in the magnetic generation of the Sun and stars. Unfortunately, at the moment observation are not able to reveal these effects. On way to understand how these turbulent effects can generate magnetic field via dynamo mechanisms is to study global 3 dimensional magnetohydrodynamic simulation of the Sun and stars. There the analysis tool testified method reveals the turbulent transport coefficients as a parametrization of the turbulent effects and therefore let us get an idea of the dynamo mechanism operating in these simulations. The most prominent mechanisms are the α effect, turbulent pumping and the turbulent diffusion. In our recent study, we find that the turbulent pumping is stronger than the meridional flow and therefore dominates the transport of magnetic field. Furthermore, all transport coefficients show strong temporal variation with the magnetic cycle, indicating a non-linear saturation mechanism for the dynamo. Only if we are able to understand the dynamos operating in simulation, we can achieve conclusion about the magnetic field generation in the Sun and stars. more
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