Atmospheric Carbon Dioxide Record from Alert, Northwest Territories, Canada
C.D. Keeling and 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
At Alert weekly air samples are collected in 5-L evacuated glass flasks exposed in triplicate. Flasks are returned to the 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 CO2-in-air calibration gases, which are currently used (Keeling et al. 2002). Data are in terms of the Scripps "03A" calibration scale.
Alert, Northwest Territories, Canada
Tundra (snow covered for almost
three quarters of the year)
82°28' N, 62°30' W
210 m above MSL
On the basis of flask samples collected at Alert and analyzed by SIO, the annual average of the fitted monthly concentrations CO2 rose from 348.48 ppmv in 1986 to 384.84 ppmv in 2007. This represents an average annual growth rate of 1.73 ppmv per year at Alert.
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- Bacastow, R.B., J.A. Adams, Jr., C.D. Keeling, D.J. Moss, T.P. Whorf, and C.S. Wong. 1980. Atmospheric carbon dioxide, the Southern Oscillation, and the weak 1975 El Niño. Science 210:66-68.
- 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., 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.
- 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.
CITE AS: Keeling, R.F., S.C.Piper, A.F. Bollenbacher and J.S. Walker. 2008. Atmospheric CO2 records from sites in the SIO air sampling network. In Trends: A Compendium of Data on Global Change. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tenn., U.S.A.