Dynamic Origins of Solar Magnetism
The magnetism that regulates solar variability is produced below the visible surface of the Sun, in the turbulent convection zone and its adjacent boundary layers. Modeling this complex system is a formidable challenge, but a hierarchical modeling approach rooted firmly in solar and stellar observations and theoretical insights has fueled substantial progress in our understanding of solar internal dynamics over the past two decades. We are now at a stage where we can begin to speak meaningfully of an integrated Sun system model that addresses both the generation of cyclic magnetic activity (the solar dynamo) and its influence on the solar corona and heliosphere. Understanding this is a prerequisite to understanding the long-term impact of solar magnetic activity on the Earth's atmosphere and space environment. I will begin this talk by describing our nascent efforts to build such a Sun system model. I will then discuss the principle uncertainties plaguing solar dynamo models and how we are addressing them with complementary modeling efforts targeted at specific physical processes. Two processes in particular stand out. First, the origin of mean flows (differential rotation and meridional circulation) and the role they play in the operation of the dynamo. Second, the process of flux emergence, which provides the link between the generation of magnetic fields and their physical manifestation in the solar atmosphere, where they shape the solar corona and power space weather.