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Published January 2007 | Supplemental Material + Published
Journal Article Open

Regional patterns of radiocarbon and fossil fuel-derived CO_2 in surface air across North America


Radiocarbon levels in annual plants provide a means to map out regional and continental‐scale fossil fuel plumes in surface air. We collected corn (Zea mays) across North America during the summer of 2004. Plants from mountain regions of western North America showed the smallest influence of fossil fuel‐derived CO_2 with a mean Δ^(14)C of 66.3‰ ±1.7‰. Plants from eastern North America and from the Ohio‐Maryland region showed a larger fossil fuel influence with a mean Δ^(14)C of 58.8‰ ± 3.9‰ and 55.2‰ ± 2.3‰, respectively, corresponding to 2.7 ppm ± 1.5 ppm and 4.3 ppm ± 1.0 ppm of added fossil fuel CO_2 relative to the mountain west. A model–data comparison suggests that surveys of annual plant Δ^(14)C can provide a useful test of atmospheric mixing in transport models that are used to estimate the spatial distribution of carbon sources and sinks.

Additional Information

© 2007 by the American Geophysical Union. Received 31 May 2006; revised 26 November 2006; accepted 11 December 2006; published 23 January 2007. We gratefully acknowledge support from NSF EAR‐0402062 and NASA NNG05GD126. We thank the following people for collecting samples: J. E. Anderson, D. Baldocchi, J. C. Beckwith, T. Berggren, J. Chanton, and M. Coakely, G. J. Collatz, M. Conte, P. S. Curtis, K. Dutta, J. Ehleringer, J. Fessenden, L. Flanagan, N. Goulden, J. Harden, S. Hobbie, A. Hoffman, D. Hollinger, R. A. Houghton, J. Hughes Martiny, P. Kasibhatla, J. Y. King, C. T. Lai, D. LeBauer, H. Liu, D. H. Loyd Jr., Y. Luo, L. Masiello, J. E. Munger, J. W. Munger, D. Nowinski, J. Okeefe, T. Perez, A. Rocha, D. R. Sandquist, T. Schimelfenig, T. Schuur, C. Scott, C. Still, A. Trumbore, S. B. Verma, C. Vogel, G. Welp, and L. Ziolkowski. We thank G. dos Santos for advice on laboratory analysis, A. V. Rocha for assistance with fieldwork, S. M. Cheong for assistance with figure design, and J. Miller and S. Lehman for sharing CO_2 and Δ^(14)C data from Niwot Ridge.

Attached Files

Published - Hsueh_et_al-2007-Geophysical_Research_Letters.pdf

Supplemental Material - downloadSupplement_doi=10.1029_2F2006GL027032_file=grl21925-sup-0001-readme.txt

Supplemental Material - downloadSupplement_doi=10.1029_2F2006GL027032_file=grl21925-sup-0002-ts01.txt

Supplemental Material - downloadSupplement_doi=10.1029_2F2006GL027032_file=grl21925-sup-0003-ts01.pdf

Supplemental Material - downloadSupplement_doi=10.1029_2F2006GL027032_file=grl21925-sup-0004-txts01.txt

Supplemental Material - downloadSupplement_doi=10.1029_2F2006GL027032_file=grl21925-sup-0005-t01.txt


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