We explore the ability of nonoscillatory advection schemes to represent the
effects of the unresolved scales of motion in numerical simulation of turb
ulent flows. We demonstrate that a nonoscillatory fluid solver can accurate
ly reproduce the dynamics of an atmospheric convective boundary layer When
an explicit turbulence model is implemented, the solver does not add any si
gnificant numerical diffusion. Of greater interest, when no explicit turbul
ence is employed the solver itself appears to include an effective subgrid
scale model. Other researchers have reported similar success, simulating tu
rbulent flows in a variety of regimes while using only nonoscillatory advec
tion schemes to model subgrid effects. At this point there is no theory jus
tifying this success, but we offer some speculations. (C)1999 Elsevier Scie
nce B.V. All rights reserved.