  We study convective overshooting by means of local 3D convection
calculations. Using a mixing length model of the solar convection zone (CZ) as
a guide, we determine the Coriolis number (Co), which is the inverse of the
Rossby number, to be of the order of ten or larger at the base of the solar CZ.
Therefore we perform convection calculations in the range Co = 0...10 and
interpret the value of Co realised in the calculation to represent a depth in
the solar CZ. In order to study the dependence on rotation, we compute the
mixing length parameters alpha_T and alpha_u relating the temperature and
velocity fluctuations, respectively, to the mean thermal stratification. We
find that the mixing length parameters for the rapid rotation case,
corresponding to the base of the solar CZ, are 3-5 times smaller than in the
nonrotating case. Introducing such depth-dependent alpha into a solar structure
model employing a non-local mixing length formalism results in overshooting
which is approximately proportional to alpha at the base of the CZ. Although
overshooting is reduced due to the reduced alpha, a discrepancy with
helioseismology remains due to the steep transition to the radiative
temperature gradient. In comparison to the mixing length models the transition
at the base of the CZ is much gentler in the 3D models. It was suggested
recently (Rempel 2004) that this discrepancy is due to the significantly larger
(up to seven orders of magnitude) input energy flux in the 3D models in
comparison to the Sun and solar models, and that the 3D calculations should be
able to approach the mixing length regime if the input energy flux is decreased
by a moderate amount. We present results from local convection calculations
which support this conjecture.
