  Three-dimensional large eddy simulations of solar surface convection using
realistic model physics are conducted. The thermal structure of convective
motions into the upper radiative layers of the photosphere, the range of
convection cell sizes, and the penetration depths of convection are
investigated. A portion of the solar photosphere and the upper layers of the
convection zone, a region extending 60 x 60 Mm horizontally from 0 Mm down to
20 Mm below the visible surface, is considered. We start from a realistic
initial model of the Sun with an equation of state and opacities of stellar
matter. The equations of fully compressible radiation hydrodynamics with
dynamical viscosity and gravity are solved. We use: 1) a high order
conservative TVD scheme for the hydrodynamics, 2) the diffusion approximation
for the radiative transfer, 3) dynamical viscosity from subgrid scale modeling.
The simulations are conducted on a uniform horizontal grid of 600 x 600, with
168 nonuniformly spaced vertical grid points, on 144 processors with
distributed memory multiprocessors on supercomputer MVS-15000BM in the
Computational Centre of the Russian Academy of Sciences.
