Complex/Dynamical Systems Seminar - Nicholas Featherstone

Rise to the Sun:  A Modeler's Perspective on the Solar Dynamo Problem

The Sun reverses its large-scale magnetic polarity once every roughly eleven years through a process known as the solar dynamo. Understanding the source of this dynamo remains a major problem in stellar astrophysics.  Whereas many phenomena that stem from the dynamo, such as the appearance and migration of sunspots at the solar surface, are amenable to direct observation, those processes that give rise to the dynamo itself reside far beneath the solar surface, well beyond the reach of current observational capabilities.  As a result, theory and, increasingly, numerical modeling play a crucial role in efforts to describe the dynamo process.  In this talk, I will provide a general overview of solar magnetism as seen from a modeler's perspective.  In particular, I will discuss the physical ingredients included in typical dynamo models and the numerical methods used to evolve such models.  I will also discuss the limitations and strengths of modern numerical approaches, what progress has been made on the dynamo problem, what we would like to achieve, and the increasingly important role played by high-performance computing in this area.