  We show that inhomogeneities in the spatial distribution of Cooper pairs and
in the phase of the local superconducting order parameter in the vicinity of a
superconductor-normal state transition (SNT) in two dimensions can be highly
sensitive to a perpendicular magnetic field. We focus on the role of orbital
effects in the field-dependence of local superfluid stiffness and
superconducting phase disorder in homogeneously-disordered two-dimensional
superconductor thin films. The relative importance of these orbital effects is
analyzed in different physical regimes dominated by Coulomb blockade, thermal
phase fluctuations and Aharanov-Bohm phase disorder respectively. Following
this approach, we obtain explicit expressions for the field dependence of
magnetoresistance and superfluid stiffness near the SNT, and attempt an
understanding of some recent experimental findings.
