The evolution of buoyant magnetic structures in the solar interior

University Of California-Santa Cruz, Santa Cruz CA

Investigators

Abstract

One of the great challenges in solar physics is to understand how solar magnetic flux floats from the Sun?s deep interior (where it is generated by the solar dynamo) to the surface. Until now, solar physicists have assumed that magnetic flux could be modeled as discrete magnetically buoyant ?flux tubes.? Recent research has suggested that this idealization might be invalid. The work proposed here will expand that work, and rethink current 3D simulations by modeling solar magnetic flux as concentrations of magnetic field embedded in a diffuse background field. If successful, the work will lead to a fundamental shift in our understanding of the evolution and dynamics of the solar magnetic field, and provide insight into the solar dynamo. The results of this work will provide a theoretical basis for DKIST observations of emerging solar magnetic flux, which is one of the principal goals of the new observatory. This work will also form the basis of a PhD thesis. The proposed work will be to develop a new model for the transport of magnetic flux from deep in the solar interior to the surface through the mechanism of magnetic buoyancy. In particular, the team will replace the idealization of discrete magnetic ?flux tubes? with more physical concentrations of magnetic field set in a diffuse background field. Field lines interweave between the magnetic concentration and the background field, resulting in very different dynamics from what one would expect with discrete flux tubes. This can include mass loss from the rising magnetic concentration, which is prohibited in the flux tube case. They will also increase the fidelity of the simulation by including turbulence in the region through which the magnetic concentration rises. The team will expand prior 2.5D studies into full 3D simulations. This will require the use of supercomputing facilities which were acquired under prior NSF support. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.