  We study the influence of the spatial resolution on scales of $5\deg$ and
smaller of solar surface magnetic field maps on global magnetohydrodynamic
solar wind models, and on a model of coronal heating and X-ray emission. We
compare the solutions driven by a low-resolution Wilcox Solar Observatory
magnetic map, the same map with spatial resolution artificially increased by a
refinement algorithm, and a high-resolution Solar and Heliospheric Observatory
Michelson Doppler Imager map. We find that both the wind structure and the
X-ray morphology are affected by the fine-scale surface magnetic structure.
Moreover, the X-ray morphology is dominated by the closed loop structure
between mixed polarities on smaller scales and shows significant changes
between high and low resolution maps. We conclude that three-dimensional
modeling of coronal X-ray emission has greater surface magnetic field spatial
resolution requirements than wind modeling, and can be unreliable unless the
dominant mixed polarity magnetic flux is properly resolved.
