Land surfaces are typically heterogeneous. This leads to significant horizontal variations in the contributors to the surface energy budget, and thus PBL structure which, in turn, can result in errors in numerical climate and weather forecast models. In order to deal with this problem, research into the variables that describe the surface and variations in surface properties need to be carried out, in order to satisfactorily represent the effects of the surface on the atmosphere. High quality comprehensive datasets are being produced and studied for comparison with models and for the development of parameterization schemes. Techniques are being developed for comparing observations of fluxes and other statistical properties of the boundary layer over horizontally heterogeneous land surfaces with model results. Researchers studying land address two complementary questions. First, how can the heterogeneity be accounted for in models with large-scale resolution, such as regional and global models? And second, how do we incorporate the effects of surface heterogeneity on the diurnal variation of PBL structure in regional and global models? Researchers in MMM are working to answer these questions and to provide better data and parameterizations of suface-atmosphere interactions for use in weather models.
NCAR Strategic Initiative: Biogeosciences:
CO2 Transport over Complex Terrain
NCAR Strategic Initiative: Wildland
Fire R&D Collaboratory
HATS (Horizontal Array Turbulence
Study)
OHATS (Ocean Horizontal Array
Turbulence Study)
LES: Large Eddy Simulation
MMM Wildfire Research