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Atmospheric CO2 from Flask Air Samples at Baring Head, New Zealand

graphics Graphics   data Data

C.D. Keeling and T.P. Whorf

Carbon Dioxide Research Group, Scripps Institution of Oceanography, University of California, La Jolla, California 92093-0444, U.S.A.

Period of Record



Atmospheric CO2 samples were collected at intervals which typically ranged from semi monthly to monthly. Samples are collected in 5-L evacuated glass flasks, and then returned to the Scripps Institution of Oceanography (SIO) where CO2 concentrations have been determined using an Applied Physics Corporation (APC) nondispersive infrared gas analyzer. Further information on measurements, calibration procedures and analysis is available in the references listed below.

Map showing location of Baring Head, New Zealand

Baring Head, New Zealand
Seashore coastal cliff
41°24' S, 174°54' E
85 m above MSL


The average of unflagged data for the first full year of measurements (1978) was 334.1 ppmv; values for 1999 averaged 365.4 ppmv, for an upward trend of 1.42 ppmv/year. (For 2000, data for April, June, September, November, and December were missing or completely flagged; for 2001, data for January, February, July, August, November, and December were missing or completely flagged.) Graphics here show the first and last year of data, to display the change in mean over time and the annual amplitudes. Long term trend curves are better displayed using SIO's PDF monthly averaged data.


CITE AS: Keeling, C.D. and T.P. Whorf. 2004. Atmospheric CO2 concentrations derived from flask air samples at sites in the SIO 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, Tennessee, U.S.A.