  We present numerical simulations of convective overshoot in a two-dimensional
model of the solar equatorial plane. The simulated domain extends from 0.001
R_sun to 0.93 R_sun, spanning both convective and radiative regions. We show
that convective penetration leads to a slightly extended, mildly subadiabatic
temperature gradient beneath the convection zone below which there is a rapid
transition to a strongly subadiabatic region. A slightly higher temperature is
maintained in the overshoot region by adiabatic heating from overshooting
plumes. This enhanced temperature may partially account for the sound speed
discrepancy between the standard solar model and helioseismology. Simulations
conducted with tracer particles suggest that a fully mixed region exists down
to at least 0.687 R_sun.
