Atmospheric Carbon Dioxide Record from Point Barrow, Alaska

Graphics    Data

Investigators

R.F. Keeling, S.C. Piper, A.F. Bollenbacher and J.S. Walker
Scripps Institution of Oceanography,
University of California,
La Jolla, California 92093-0244, U.S.A.

Period of Record

1974-2007

Methods

Carbon dioxide was first measured at Barrow, Alaska, by Kelley and co-workers from the University of Washington during the 1960s through the use of a continuously operating analyzer. From January 1974 through February 1982, air samples were collected biweekly in triplicate 2-L evacuated glass flasks. Since March 1982, weekly air samples have been collected in 5-L evacuated glass flask pairs. Flasks are returned to the Scripps Institution of Oceanography (SIO) for CO₂ determinations, which are made using an Applied Physics Corporation nondispersive infrared gas analyzer. In May 1983, the CO₂-in-N₂ calibration gases were replaced with the CO₂-in-air calibration gases, which are currently used (Keeling et al. 2002). Data are in terms of the Scripps "03A" calibration scale.

Barrow, Alaska, U.S.A.
On the coast of the Arctic Ocean
71°19' N, 156°36' W, 11 m above MSL

Trends

The Barrow record shows the large seasonal amplitude typical of high northerly latitude sites. Since 1975, the annual average of the fitted CO₂ concentrations at Barrow has risen from 333.27 ppmv in 1975 to 385.13 ppmv. This represents an average annual increase of 1.62 ppmv per year.

References

• Keeling, C.D. 1984. Atmospheric and oceanographic measurements needed for establishment of a data base for carbon dioxide from fossil fuels. In The Potential Effects of Carbon Dioxide-Induced Climatic Changes in Alaska. (Miscellaneous, etc.). The Proceedings of a Conference. Fairbanks, Alaska, April 7-8, 1982. School of Agriculture and Land Resources Management, University of Alaska, Fairbanks.
• Keeling, C.D., R.B. Bacastow, A.F. Carter, S.C. Piper, T.P. Whorf, M. Heimann, W.G. Mook, and H. Roeloffzen. 1989. A three-dimensional model of atmospheric CO₂ transport based on observed winds: 1. Analysis of observational data. In D.H. Peterson (ed.), Aspects of Climate Variability in the Pacific and the Western Americas. Geophysical Monograph 55:165-235.
• Keeling, C.D., P.R. Guenther, G. Emanuele III, A. Bollenbacher, and D.J. Moss. 2002. Scripps Reference Gas Calibration System for Carbon Dioxide-in-Nitrogen and Carbon Dioxide-in-Air Standards: Revision of 1999 (with Addendum). SIO Reference Series No. 01-11.
• Keeling, C.D., S.C. Piper, R. B. Bacastow, M. Wahlen, T.P. Whorf, M. Heimann, and H.A. Meijer, Atmospheric CO₂ and ¹³CO₂ exchange with the terrestrial biosphere and oceans from 1978 to 2000: Observations and carbon cycle implications, pages 83-113, in "A History of Atmospheric CO₂ and its effects on Plants, Animals, and Ecosystems", editors, Ehleringer, J.R., T.E. Cerling, M.D. Dearing, Springer Verlag, New York, 2005.