Global, Continental, and Regional CO2: New developments in measuring and modeling Atmospheric Distributions and Land-Ocean-Atmosphere Exchanges

Steven Wofsy, Harvard University, wofsy@fas.harvard.edu (Presenting)

We provide an overview of global, continental, and regional scale sources and sinks of CO2 and other greenhouse gases from the top-down perspective. After a period of intensive development, knowledge and capabilities in this have surged in both the US and Europe as new data sources and new methods have borne fruit. Until recently, almost all top-down analyses relied upon the network of NOAA flask stations in remote regions, utilizing large scale models, limiting accuracy and fidelity especially for continental and smaller scales. New data sources include routine and intensive aircraft sampling, tall tower measurements, total column measurements using Fourier Transform Spectrometers, and (soon) total column data from satellites. New analytic tools include the Ensemble Kalman Filter (CarbonTracker), Lagrangian Particle Dispersion Models, and GEOS applications. There have been major advances in representing of land surface fluxes via better models, application of geostatistical methods, and assimilation of eddy flux and remote sensing data. All of these advances have benefited from CCE field and modeling programs, as our examples will show. We conclude with an assessment of science and validation needs for the next phase of study.