Understanding small solar magnetic structures: Comparing numerical simulations to observations

We present direct comparisons of small magnetic structures observed in the solar photosphere with the results from numerical simulations of those stru ctures. We compare diagnostic signatures derived from emergent Stokes polar ization spectra from both the observed and model atmospheres, the former re corded with the National Solar Observatory/High Altitude Observatory Advanc ed Stokes Polarimeter, the latter from a fully dynamic MI-ID simulation of a magnetic Aux sheet in a convective atmosphere. We focus on the asymmetrie s in the Stokes V spectra and find, first and foremost, that the asymmetrie s from the observed Stokes I and V in and around solar pores and azimuth ce nters (ACs) are quantitatively comparable to those derived from the simulat ion. We also find enhanced Stokes V asymmetry on the periphery of pores and ACs. We interpret this as a consequence of strong downdrafts in the surrou ndings of these magnetic structures, accompanied by the expansion of the ma gnetic field lines with height above these field-free downdrafts (the "cano py effect"). The magnetic canopy can be present whether or not there is a c ontinuum signature (i.e., a dark "pore"). Not surprisingly, the patterns an d magnitudes of asymmetries scale with the size of the magnetic element. In the interior of the pores and ACs. we find evidence for mixed up- and down flows, with little spatial correlation between the zero-crossing shift of t he V profile and the V amplitude. Finally, we report on asymmetries observe d in the linear polarization P-lin(lambda) = [Q(lambda)(2) + U(lambda)(2)]( 1/2), finding further support for the presence of the magnetic canopy from those diagnostics. We additionally present expectations for spectropolarime tric observations at significantly higher spatial resolution.