A global multi-year biophysical land surface data set from NOAA AVHRR data

Abstract

A global, monthly, 1 by 1 degree biophysical land surface data set for 1982-1990 is derived from data collected by the Advanced Very High Resolution Radiometer (AVHRR) on board the NOAA-7, -9, and -11 satellites. The AVHRR data are adjusted for sensor degradation, volcanic aerosol effects, cloud contamination, short term atmospheric effects (<=2 months), solar zenith angle variations, and missing data. Biophysical parameters such as leaf area index (LAI), fraction of photosynthetically active radiation absorbed by vegetation (FPAR), and albedo are estimated. Evaluation shows that the interannual variation in the data is significantly improved by the adjustments. Algorithms to derive biophysical parameters are tested with data from intensive remote sensing experiments (FIFE, OTTER, BOREAS, HAPEX Sahel). Albedo estimates from this study show general agreement with albedo estimates from the Earth Radiation Budget Experiment (ERBE), but also indicate a need for improved soil reflectance estimates. The multi-year land surface datasets presented in this study are a unique compilation of spatially and temporarily consistent biophysical parameters to study spatial, seasonal, and interannual variation in vegetation and interactions with the atmosphere, the hydrological cycle, the energy balance, and biogeochemical cycles. The biophysical data will be distributed by the Goddard Distributed Active Archive Center (DAAC) [URL: http//daac.gsfc.nasa.gov/] as a precursor to the International Satellite Land Surface Climatology Project (ISLSCP) Initiative II during the first half of 1999.