Synthesis of satellite data with process modeling of the North American carbon sink at high resolution

A better understanding of the North American terrestrial sink, including its size, variation, and mechanisms, requires quantification of the spatial heterogeneity and temporal variability in ecosystem carbon fluxes at a fine scale with observational data. Satellite remote sensing provides spatially contiguous, time-specific, and high- resolution data for achieving that goal, but the preprocessing needed to fully exploit satellite data sets for more than 20 years has only recently become available. In this study, we used our ecosystem carbon cycle model that is driven with biological and meteorological variables derived from AVHRR data to estimate the changes in net primary production (NPP), soil carbon respiration, and net ecosystem production (NEP) throughout North America for the period 1981-2000 at 8km and 10-day resolution. Through modeling and analyses, the linkages between terrestrial carbon uptake, changes in climate and atmospheric CO2, and land use was established. Special attention was given to the dynamic responses of North American terrestrial ecosystem carbon sink to global warming and periodic climate fluctuation such as El Ni¤o Southern Oscillations and North Atlantic Oscillations. The carbon sequestration of different cover types and the effects of land use history preceding and during the satellite era is also investigated