  We analyze recent high resolution photospheric small-scale dynamo simulations
that were computed with the MURaM radiative MHD code. We focus the analysis on
newly forming downflow lanes in exploding granules since they show how weakly
magnetized regions in the photosphere (center of granules) evolve into strongly
magnetized regions (downflow lanes). We find that newly formed downflow lanes
exhibit initially mostly a laminar converging flow that amplifies the vertical
magnetic field embedded in the granule from a few 10 G to field strengths
exceeding 800 G. This results in extended magnetic sheets that have a length
comparable to granular scales. Field amplification by turbulent shear happens
first a few 100 km beneath the visible layers of the photosphere. Shallow
recirculation transports the resulting turbulent field into the photosphere
within minutes, after which the newly formed downflow lane shows a mix of
strong magnetic sheets and turbulent field components. We stress in particular
the role of shallow and deep recirculation for the organization and strength of
magnetic field in the photosphere and discuss the photospheric and
sub-photospheric energy conversion associated with the small-scale dynamo
process. While the energy conversion through the Lorentz force depends only
weakly on the saturation field strength (and therefore deep or shallow
recirculation), it is strongly dependent on the magnetic Prandtl number. We
discuss the potential of these findings for further constraining small-scale
dynamo models through high resolution observations.
