Understanding the effects of heterogeneous surfaces on the planetary boundary layer is a key to the study of atmosphere-biosphere interactions. Local surface properties lead to differences in surface fluxes of heat and moisture.The uneven surface fluxes combined with terrain irregularities to generate both standing and transient eddies, which could modify the local turbulent fluxes. The boreal ecosystem-atmosphere study (BOREAS) was designed in part to characterize fluxes over a heterogeneous temperate-zone ecosystem and to validate process models. The challenge involved blending measurements from several platforms, as well as finding ways to relate surface characteristics to airborne measured surface fluxes.
Our paper is based on analysis of aircraft-based flux easurements over two 16 km x 16 km heterogeneous sites in BOREAS 1994 and 1996. It presents statistical evaluation of the patterns obtained from mapping of aircraft measured fluxes, comparison of the 1994 and 1996 data to determine the areas at which structural and biophysical changes occured at the sites and the extent to which these changes are reflected on the flux maps.Improved surface classification for the site will be developed from satellite and ground based information and variograms will be used to relate the scale of variability in surface characteristics to those of the measured fluxes. Our analysis will also compare aircraft-based measurement of albedo, net radiation, surface temperature, sensible heat flux and latent heat flux against those predicted by Global Environmental Multiscale (GEM) model of the Canadian Meteorologic Centre.