Abstract
Seasonal and latitudinal variations of column averaged volume-mixing ratios of atmospheric CO2
Institute of Environmental Physics, University of Bremen, Bremen, Germany
Division of Geological and Planetary Sciences, California Institute of Technology (CIT), Pasadena, California, USA
Division of Geological and Planetary Sciences, California Institute of Technology (CIT), Pasadena, California, USA
Max Planck Institute for Biogeochemistry (MPI-BGC), Jena, Germany
Institute of Environmental Physics, University of Bremen, Bremen, Germany
Jet Propulsion Laboratory (JPL), Pasadena, California, USA
Institute of Environmental Physics, University of Bremen, Bremen, Germany
Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany
Alfred Wegener Institute for Polar and Marine Research, Potsdam, Germany
Column-averaged volume mixing ratios of CO2 have been obtained by ground based high-resolution solar absorption spectrometry at Ny-Alesund (Spitsbergen, 79°N) in 2002–2003 and during two ship cruises (54°N–34°S) on the Atlantic in 2003. Precisions are better than 0.4% at Ny-Alesund and better than 0.6% for the cruises. The observed 11 ppmv (part per million by volume) seasonal amplitude of the CO2 column at Ny-Alesund is about 5 ppmv smaller than surface in situ data and 2–4 ppmv greater than model-predictions. The latitudinal gradient of column CO2 inferred from shipborne measurements is less than 2 ppmv in Oct/Nov 2003. During the cruise in Jan/Feb 2003 the observed latitudinal variation is about 7 ppmv. This strong variation is caused by pollution events (biomass burning) and natural variations. Low CO2 columns observed between 5°S–15°S are attributed to a strong seasonal amplitude of CO2 over Central Africa.
Received 23 September 2004; accepted 18 January 2005; published 5 February 2005.
Citation: (2005), Seasonal and latitudinal variations of column averaged volume-mixing ratios of atmospheric CO2, Geophys. Res. Lett., 32, L03808, doi:10.1029/2004GL021597.
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