  We present the results of a simulation of a wind-driven non-linear gravity
wave breaking on the surface of a white dwarf. The ``wind'' consists of H/He
from an accreted envelope, and the simulation demonstrates that this breaking
wave mechanism can produce a well-mixed layer of H/He with C/O from the white
dwarf above the surface. Material from this mixed layer may then be transported
throughout the accreted envelope by convection, which would enrich the C/O
abundance of the envelope as is expected from observations of novae.
