USING SIMILARITY THEORY TO PARAMETERIZE MESOSCALE HEAT FLUXES GENERATED BY SUBGRID-SCALE LANDSCAPE DISCONTINUITIES IN GCMS

Similarity theory was used to develop a parameterization of mesoscale heat fluxes induced by landscape discontinuities for large-scale atmos pheric models (e.g., general circulation models). For this purpose, Bu ckingham Pi theory, a systematic method for performing dimensional ana lysis, was used to derive a set of dimensionless groups, which describ es the large-scale atmospheric background conditions, the spatial vari ability of surface sensible heat flux, and the characteristic structur e of the landscape. These dimensionless groups were used to calculate the coefficients of a fourth-order Chebyshev polynomial, which represe nts the vertical profiles of dimensionless mesoscale heat fluxes obtai ned for a broad range of large-scale atmospheric conditions and differ ent landscapes. The numerous three-dimensional numerical experiments p erformed to evaluate this similarity relationship suggest that the par ameterization is quite robust.