The Physics of Active Region Decay

University Of California-Berkeley, Berkeley CA

Investigators

Abstract

Using magnetohydrodynamic (MHD) simulations, the proposing team will investigate the evolution and decay of active regions in the solar atmosphere. This effort will focus on the physics of active region decay because of its importance to the solar cycle dynamo and for determining the detailed magnetic structure of both small-scale and global phenomena in the solar corona. This effort is motivated by the fact that solar active regions (seen as sunspot groups in the photosphere and bright knots of X-ray emission in full disk coronal images) are the largest and most important contributors to solar activity. Solar eruptive phenomena (such as solar flares and coronal mass ejections, or CMEs) and nearly all of the observed X-ray and extreme ultraviolet radiation that reaches the Earth are linked to active region magnetic fields, but the life cycle of these active regions is not yet well understood. The Principal Inverstigar (PI) notes that active regions are an important driver of space weather and that this work will therefore have an impact on operational forecasts, especially of the global magnetic properties of the Sun and large-scale CMEs. The PI's team will provide their numerical codes and datasets to the community for testing and validation, and they expect that their numerical techniques will have many additional applications. The proposing team's tools will be made available under an open source license for use in a wide range of studies in which radiative MHD models are needed.