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Atmos. Chem. Phys. Discuss., 12, 18993-19037, 2012
www.atmos-chem-phys-discuss.net/12/18993/2012/ doi:10.5194/acpd-12-18993-2012 © Author(s) 2012. This work is distributed under the Creative Commons Attribution 3.0 License. |
A 60-yr record of atmospheric carbon monoxide reconstructed from Greenland firn air
1Institute of Arctic and Alpine Research (INSTAAR), University of Colorado, Boulder, CO 80309, USA
2UJF – Grenoble 1/CNRS, Laboratoire de Glaciologie et Géophysique de l'Environnement (LGGE) UMR 5183, Grenoble, 38041, France
3NOAA ESRL Global Monitoring Division, Boulder, CO 80305, USA
4Centre for Australian Weather and Climate Research, CSIRO Marine and Atmospheric Research, Aspendale, Victoria 3195, Australia
5Institut für Umweltphysik, Heidelberg University, 69120 Heidelberg, Germany
6School of Marine and Atmospheric Sciences/Institute for Terrestrial and Planetary Atmospheres, State University of New York at Stony Brook, Stony Brook, NY 11794, USA
7Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen, 2100 København Ø, Denmark
8School of Environmental Sciences, University of East Anglia (UEA), Norwich NR4 7TJ, UK
9University of Berne, Physics Institute, 3012 Bern, Switzerland
10Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, 92093, USA
11UJF – Grenoble 1/CNRS, Grenoble Image Parole Signal Automatique (GIPSA-lab), UMR 5216, B.P. 46, 38402 St Martin d'Hères, France
12Department of Physics and Astronomy, Bowdoin College, 8800 College Station, Brunswick, ME 04011, USA
13National Center for Atmospheric Research, Boulder, CO 80301 USA
14Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, USA
15Geological Sciences and Environmental Studies, University of Colorado, Boulder, CO 80309, USA
*now at: Department of Earth and Environmental Sciences, University of Rochester, Rochester, NY 14627, USA
Abstract. We present a reconstruction of the Northern Hemisphere (NH) high latitude atmospheric carbon monoxide (CO) mole fraction from Greenland firn air. Firn air samples were collected at three deep ice core sites in Greenland (NGRIP in 2001, Summit in 2006 and NEEM in 2008). CO records from the three sites agree well with each other as well as with recent atmospheric measurements, indicating that CO is well preserved in the firn at these sites. CO atmospheric history was reconstructed back to the year 1950 from the measurements using a combination of two forward models of gas transport in firn and an inverse model. The reconstructed history suggests that Arctic CO was already higher in 1950 than it is today. CO mole fractions rose gradually until the 1970s and peaked in the 1970s or early 1980s, followed by a decline to today's levels. We compare the CO history with the atmospheric histories of methane, light hydrocarbons, molecular hydrogen, CO stable isotopes and hydroxyl radical (OH), as well as with published CO emission inventories and results of a historical run from a chemistry-transport model. We find that the reconstructed Greenland CO history cannot be reconciled with available emission inventories unless large changes in OH are assumed. We argue that the available CO emission inventories chronically underestimate NH emissions, and fail to capture the emission decline starting in the late 1970s, which was most likely due to reduced emissions from road transportation in North America and Europe.
Citation: Petrenko, V. V., Martinerie, P., Novelli, P., Etheridge, D. M., Levin, I., Wang, Z., Blunier, T., Chappellaz, J., Kaiser, J., Lang, P., Steele, L. P., Hammer, S., Mak, J., Langenfelds, R. L., Schwander, J., Severinghaus, J. P., Witrant, E., Petron, G., Battle, M. O., Forster, G., Sturges, W. T., Lamarque, J.-F., Steffen, K., and White, J. W. C.: A 60-yr record of atmospheric carbon monoxide reconstructed from Greenland firn air, Atmos. Chem. Phys. Discuss., 12, 18993-19037, doi:10.5194/acpd-12-18993-2012, 2012.