Abstract
The results from some of the latest experimental and theoretical studies of the planetary boundary layer (PBL) ire used to revise certain better known schemes (Clarke, 1970b; Deardorff, 1972b) of parameterizing the boundary layer in general circulation models (GCM's). For high-resolution models, our proposed scheme is based on the surface layer similarity theory relations derived by Businger et al. (1971) from the Kansas tower data. For low-resolution GCM'S, the proposed scheme is based on the generalized PBL-similarity theory with the various similarity functions evaluated from the best available numerical models of the boundary layer. The usual practice of specifying a single value for the roughness parameter (z0) for all the land surfaces in a GCM is questioned. The specified z0 value at each grid point should actually reflect the roughness characteristics of the surface represented by it.
