Abstract. A basic methodological premise in the design of the Boreal EcosystemAtmosphere Study (BOREAS) is that the findings and models obtained at the stand level can be applied at the landscape, regional and global levels by using spatially comprehensive data sets, in particular satellite observations and meteorological measurements. Since many of the processes of interest are strongly influenced by solar radiation, satellite measurements at optical wavelengths are of fundamental importance. We describe a satellite data set and derived products prepared for the studies of the ecosystem-atmosphere interactions, including the scaling up of site and landscape measurements, model development and validation, and many other applications. It is derived from daily measurements by the advanced very high resolution radiometer (AVHRR) onboard the NOAA 11 satellite. The data set was obtained through a compositing process to minimize the contamination by clouds. Subsequently, the ABC3 procedure [Cihlar et al., 1997] was applied to remove atmospheric attenutation effects, identify residual clouds or snow-covered pixels and remove the effect of this contamination, remove bidirectional reflectance effects, and correct for surface emissivity effects. The paper briefly reviews the correction procedures, discusses the characteristics of the corrected data set, and presents several derived products of biophysical parameters, including leaf area index and the fraction of photosynthetically active radiation, vegetation index accumulated over the growing season, and the daily total absorbed photosynthetically active radiation. Although the interactive surface-atmosphere processes ultimately take place at the molecular and cellular level, they must be characterized at larger spatial scales. This is necessary because most of the variability and dynamics of interest occurs at landscape, region, and global levels. It is at these larger scales that the impact of seasonal and interannual variability is most directly experienced by other components of the natural or anthropogenic environment. In the "scaling up," i.e., extending the knowledge and understanding of detailed process studies from small sites to the area beyond, satellite remote sensing provides the principal tool. Thus the second overarching objective of BOREAS was to "develop and validate remote sensing algorithms to transfer our understanding of the above pro-