The idea of this project is to study the consequences of reduced
metallicity on magnetized stellar atmospheres. For this purpose
realistic local box simulations of near surface magneto-convection
with prescribed magnetic flux are carried out with the MHD version of
the CO5BOLD code for the Sun and a metal-poor solar analog.

Through a differential comparison of the resulting
magneto-hydrodynamical model atmospheres we will study the the
influence of the metallicity on the properties of magnetic flux tubes
and their influence on the thermal structure and dynamics of the
photospheric layers.

Further questions can be addressed by computing synthetic (Stokes)
spectra based on the MHD model atmospheres: what is the relation
between the mean magnetic flux and (i) the continuum intensity
contrast, (ii) the apparent microturbulence, and (iii) the stellar
micro-variability? How large are the uncertainties of spectroscopic
abundance determinations due to the ignorance of magnetic fields?