Seasonal AVHRR multichannel data sets and products for studies of surface-atmosphere interactions

A basic methodological premise in the design of the Boreal Ecosystem-Atmosphere 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 ct at., 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.