Authors: W.P. Abbett
Affiliation: Space Sciences Laboratory, University of California, Berkeley
How can we understand the connection between the “isolated” flux
systems that form and evolve within the high-beta turbulent convection zone
with the magnetic fields of the low-beta solar corona? It remains computationally
intractable to simulate the evolution of active-region magnetic fields throughout
the entirety of the solar interior and atmosphere. Thus, we are faced with a
choice. We can severely restrict the size of the computational domain, include
a small portion of the sub-surface convective envelope along with the visible
surface layers, and simulate the evolution of magnetic fields in a plasma that
transitions from a high-beta to low-beta regime over the many pressure scale
heights of the photosphere, chromosphere, transition region, and low corona;
or we can drive large-scale models of the solar atmosphere with pre-existing
sub-surface calculations or observations of the vector magnetic field at the
solar photosphere.
Since the solar photosphere necessarily represents the visible lower boundary
of data-driven models of the solar corona (and large-scale Sun-to-Earth models
being developed by collaborative projects such as CISM and MURI for use as space
weather forecasting tools), we have focused on the latter method. We have made
progress developing techniques necessary to initiate data-driven calculations,
and to update the electric field in the boundary layers of an MHD model atmosphere
when a true sub-surface coupling is not possible. I will summarize our group's
modeling efforts in these areas.