  Scanning Hall probe and local Hall magnetometry measurements have been used
to investigate flux distributions in large mesoscopic superconducting disks
with sizes that lie near the crossover between the bulk and mesoscopic vortex
regimes. Results obtained by directly mapping the magnetic induction profiles
of the disks at different applied fields can be quite successfully fitted to
analytic models which assume a continuous distribution of flux in the sample.
At low fields, however, we do observe clear signatures of the underlying
discrete vortex structure and can resolve the characteristic mesoscopic
compression of vortex clusters in increasing magnetic fields. Even at higher
fields, where single vortex resolution is lost, we are still able to track
configurational changes in the vortex patterns, since competing vortex orders
impose unmistakable signatures on "local" magnetisation curves as a function of
the applied field. Our observations are in excellent agreement with molecular
dynamics numerical simulations which lead us to a natural definition of the
lengthscale for the crossover between discrete and continuum behaviours in our
system.
