Journal cover Journal topic
Biogeosciences An interactive open-access journal of the European Geosciences Union
Journal topic
Volume 10, issue 1 | Copyright

Special issue: REgional Carbon Cycle Assessment and Processes (RECCAP)

Biogeosciences, 10, 607-627, 2013
https://doi.org/10.5194/bg-10-607-2013
© Author(s) 2013. This work is distributed under
the Creative Commons Attribution 3.0 License.

Research article 29 Jan 2013

Research article | 29 Jan 2013

An assessment of the Atlantic and Arctic sea–air CO2 fluxes, 1990–2009

U. Schuster1, G. A. McKinley2, N. Bates3, F. Chevallier4, S. C. Doney5, A. R. Fay2, M. González-Dávila6, N. Gruber7, S. Jones1, J. Krijnen1, P. Landschützer1, N. Lefèvre8, M. Manizza9, J. Mathis10, N. Metzl11, A. Olsen12, A. F. Rios13, C. Rödenbeck14, J. M. Santana-Casiano6, T. Takahashi15, R. Wanninkhof16, and A. J. Watson1 U. Schuster et al.
  • 1University of East Anglia, Norwich, UK
  • 2University of Wisconsin, Madison, WI, USA
  • 3Bermuda Institute of Ocean Science, Bermuda
  • 4LSCE-IPSL, Paris, France
  • 5Woods Hole Oceanographic Institution, Woods Hole, MA, USA
  • 6Universidad de Las Palmas de Gran Canaria, Las Palmas, Gran Canaria, Spain
  • 7ETH-Zürich, Zürich, Switzerland
  • 8LOCEAN, Université Pierre et Marie Curie, Paris, France
  • 9Scripps Institution of Oceanography, La Jolla, CA, USA
  • 10NOAA Pacific Marine Environmental Laboratory, Seattle, WA, USA
  • 11LOCEAN-IPSL, CNRS, UPMC, Paris, France
  • 12Uni Research, Bergen, Norway
  • 13Instituto de Investigaciones Marinas, IIM-CSIC, Vigo, Spain
  • 14Max-Planck-Institut für Biogeochemie, Jena, Germany
  • 15Lamont Doherty Earth Observatory of Columbia University, Palisades, NY, USA
  • 16NOAA/Atlantic Oceanographic and Meteorological Laboratory, Miami, FL, USA

Abstract. The Atlantic and Arctic Oceans are critical components of the global carbon cycle. Here we quantify the net sea–air CO2 flux, for the first time, across different methodologies for consistent time and space scales for the Atlantic and Arctic basins. We present the long-term mean, seasonal cycle, interannual variability and trends in sea–air CO2 flux for the period 1990 to 2009, and assign an uncertainty to each. We use regional cuts from global observations and modeling products, specifically a pCO2-based CO2 flux climatology, flux estimates from the inversion of oceanic and atmospheric data, and results from six ocean biogeochemical models. Additionally, we use basin-wide flux estimates from surface ocean pCO2 observations based on two distinct methodologies. Our estimate of the contemporary sea–air flux of CO2 (sum of anthropogenic and natural components) by the Atlantic between 40° S and 79° N is −0.49 ± 0.05 Pg C yr−1, and by the Arctic it is −0.12 ± 0.06 Pg C yr−1, leading to a combined sea–air flux of −0.61 ± 0.06 Pg C yr−1 for the two decades (negative reflects ocean uptake). We do find broad agreement amongst methodologies with respect to the seasonal cycle in the subtropics of both hemispheres, but not elsewhere. Agreement with respect to detailed signals of interannual variability is poor, and correlations to the North Atlantic Oscillation are weaker in the North Atlantic and Arctic than in the equatorial region and southern subtropics. Linear trends for 1995 to 2009 indicate increased uptake and generally correspond between methodologies in the North Atlantic, but there is disagreement amongst methodologies in the equatorial region and southern subtropics.

Download & links
Publications Copernicus
Special issue
Download
Citation
Share