Accurate descriptions of the carbon budget at regional to global scales would improve our understanding of feedbacks between the land and climate and would be of substantial assistance in policy making in the climate area. Although there is general agreement that North America is a large sink for carbon, the size and distribution of this sink are not well known and there are large uncertainties in its variation in space and time. Recent measurements of local carbon fluxes using fast and accurate technology, development of new computer models and techniques, and improvements in the retrieval and analysis of satellite information, have created new opportunities. This project will capitalize on these advances in several ways. The project will integrate continuous local carbon flux observations made at the tops of towers, satellite and aircraft remote sensing data, and new data on important ecosystems of the country (such as the amount of plant mass and nitrogen content). Advanced methods will be used to merge the ground and remote information into models that consider its distribution in space and dynamics in time. Analysis of the uncertainties involved will also be conducted of the data and the models. The results will include estimates of carbon sinks and sources on land and identification of what affects them from year to year, with particular focus on extreme conditions, such as severe droughts, wildfires, or timber harvesting.
This work will provide a new benchmark for the amount and dynamics of carbon in North American ecosystems. The results will be of use in national climate change assessments, especially because extreme climate events and other disturbances are generally projected to be more severe and frequent in the future. The project will also develop methods that are more generally useful and that could be adapted by environmental observation networks and used for making and evaluating predictions of future conditions. Release of project data and results to other scientists will be done through participation of the project scientists in meetings and publications. The work will also contribute to several education activities aimed at high school education and teacher training.
