Observations of radiocarbon in CO2at La Jolla, California, USA 1992–2007: Analysis of the long-term trend

@article{Graven2012ObservationsOR,
  title={Observations of radiocarbon in CO2at La Jolla, California, USA 1992–2007: Analysis of the long-term trend},
  author={Heather D. Graven and Thomas P. Guilderson and Ralph F. Keeling},
  journal={Journal of Geophysical Research},
  year={2012},
  volume={117}
}
[1] High precision measurements of Δ14C were performed on CO2 sampled at La Jolla, California, USA over 1992–2007. A decreasing trend in Δ14C was observed, which averaged −5.5 ‰ yr−1 yet showed significant interannual variability. Contributions to the trend in global tropospheric Δ14C by exchanges with the ocean, terrestrial biosphere and stratosphere, by natural and anthropogenic 14C production and by 14C-free fossil fuel CO2 emissions were estimated using simple models. Dilution by fossil… 

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