  We present a study of the influence of magnetic field strength and morphology
in Type Ia Supernovae and their late-time light curves and spectra. In order to
both capture self-consistent magnetic field topologies as well evolve our
models to late times, a two stage approach is taken. We study the early
deflagration phase (1s) using a variety of magnetic field strengths, and find
that the topology of the field is set by the burning, independent of the
initial strength. We study late time (~1000 days) light curves and spectra with
a variety of magnetic field topologies, and infer magnetic field strengths from
observed supernovae. Lower limits are found to be 106G. This is determined by
the escape, or lack thereof, of positrons that are tied to the magnetic field.
The first stage employs 3d MHD and a local burning approximation, and uses the
code Enzo. The second stage employs a hybrid approach, with 3D radiation and
positron transport, and spherical hydrodynamics. The second stage uses the code
HYDRA. In our models, magnetic field amplification remains small during the
early deflagration phase. Late-time spectra bear the imprint of both magnetic
field strength and morphology. Implications for alternative explosion scenarios
are discussed.
