Turbulent dynamo simuleringar i sfärisken skalsegmenten


Funding source

Swedish Research Council - Vetenskapsrådet (VR)


Project Details

Start date: 01/01/2012
End date: 31/12/2014
Funding: 1650000 SEK


Description

High resolution simulations of forced hydromagnetic turbulence in a rotating spherical shell segment will be conducted in order to improve our understanding of the nature of dynamo action in the Sun. Magnetic helicity fluxes are expected to remove excess magnetic *waste* from the sun to avoid so-called catastrophic quenching. In the Sun this may occur in the form of coronal mass ejections which can, in a simplified manner, also occur in the simulation. The simulations will be done with a new version of the Pencil Code which allows for the use of spherical coordinates. Previous simulations by other groups using full spherical shells yield only weak azimuthally averaged fields. This may be due to insufficient scale separation and weak magnetic helicity fluxes, as well as due to the absence of the near-surface shear layer. A more realistic simulation in a spherical shell segment is needed to produce dynamo action that resembles the sun more closely. Understanding the solar dynamo is of great practical importance given that solar activity is believed to affect the climate and is certainly crucial for predicting the extend of the outer atmosphere and hence the amount of friction experienced by artificial satellites.

Last updated on 2017-31-03 at 12:56