Modeling the Physical Connection Between the Solar Interior and Atmosphere

Understanding how magnetic flux and energy emerges from the Sun's turbulent interior (where it is generated) into the solar corona is of great importance to a number of challenging, unsolved problems in solar and heliospheric physics. The solar magnetic field provides the energy for eruptive events such as solar flares and coronal mass ejections (CMEs) --- the principle drivers of the most energetic and disruptive space weather events here at Earth --- and plays an integral role in all aspects of the solar activity cycle. Observations of the solar atmosphere allow us to explore the fundamental physics of magnetized plasmas in conditions that cannot be reproduced in terrestrial laboratories.

With the wealth of data from NASA missions such as, e.g., SOHO, SDO, STEREO, Hinode, and IRIS, it is evident that the dynamic interaction of magnetic structures observed at the Sun's photosphere and in the solar atmosphere occurs over a vast range of spatial and temporal scales.  Emerging active regions often develop magnetic connections to other regions of activity some distance away on the solar disk, and always emerge into a global coronal field whose structural complexity is a function of the solar cycle.

Yet even small-scale dynamic interactions can trigger rapid changes in the large-scale coronal field sufficient to power flares and CMEs.  These vast spatial and temporal disparities --- coupled with the physical differences between the plasma of the solar interior and atmosphere --- are the principal challenge of those attempting to model solar activity, and better predict space weather.

In this overview, I will summarize recent progress in the effort to dynamically model the Sun's upper convection zone-to-corona system over large spatial scales, and will present the initial results from a new, global radiative-MHD model of the upper convection zone-to-corona system, RADMHD2. I will discuss how physics-based numerical models of the convection zone-to-corona system can be used to guide the development and testing of data-driven and assimilative models of CME initiation and propagation.

Speaker: William P. Abbett, UC Berkeley