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JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 113, G01023, doi:10.1029/2007JG000435, 2008

An estimate of monthly global emissions of anthropogenic CO₂: Impact on the seasonal cycle of atmospheric CO₂

D. J. Erickson III

Computational Earth Sciences Group, Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
Nicholas School of the Environment and Earth Sciences, Duke University, Durham, North Carolina, USA

R. T. Mills

Computational Earth Sciences Group, Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA

J. Gregg

Geography Department, University of Maryland, College Park, Maryland, USA

T. J. Blasing

Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA

F. M. Hoffman

Computational Earth Sciences Group, Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA

R. J. Andres

Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA

M. Devries

Computational Earth Sciences Group, Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
School of Engineering, Vanderbilt University, Nashville, Tennessee, USA

Z. Zhu

Laboratory for Atmospheres, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA

S. R. Kawa

Laboratory for Atmospheres, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA

Abstract

Monthly estimates of the global emissions of anthropogenic CO₂ are presented. Approximating the seasonal CO₂ emission cycle using a 2-harmonic Fourier series with coefficients as a function of latitude, the annual fluxes are decomposed into monthly flux estimates based on data for the United States and applied globally. These monthly anthropogenic CO₂ flux estimates are then used to model atmospheric CO₂ concentrations using meteorological fields from the NASA GEOS-4 data assimilation system. We find that the use of monthly resolved fluxes makes a significant difference in the seasonal cycle of atmospheric CO₂ in and near those regions where anthropogenic CO₂ is released to the atmosphere. Local variations of 2–6 ppmv CO₂ in the seasonal cycle amplitude are simulated; larger variations would be expected if smaller source-receptor distances could be more precisely specified using a more refined spatial resolution. We also find that in the midlatitudes near the sources, synoptic scale atmospheric circulations are important in the winter and that boundary layer venting and diurnal rectifier effects are more important in the summer. These findings have implications for inverse-modeling efforts that attempt to estimate surface source/sink regions especially when the surface sinks are colocated with regions of strong anthropogenic CO₂ emissions.

Received 27 February 2007; accepted 4 December 2007; published 15 March 2008.

Keywords: carbon cycle; atmospheric transport.

Index Terms: 0428 Biogeosciences: Carbon cycling (4806); 0478 Biogeosciences: Pollution: urban, regional and global (0345, 4251); 1626 Global Change: Global climate models (3337, 4928); 1622 Global Change: Earth system modeling (1225); 1610 Global Change: Atmosphere (0315, 0325).

Subscriber Access to Full Article (Nonsubscribers may purchase for $9.00, Includes print PDF, file size: 2079375 bytes)

Citation: Erickson, D. J., III, R. T. Mills, J. Gregg, T. J. Blasing, F. M. Hoffman, R. J. Andres, M. Devries, Z. Zhu, and S. R. Kawa (2008), An estimate of monthly global emissions of anthropogenic CO₂: Impact on the seasonal cycle of atmospheric CO₂, J. Geophys. Res., 113, G01023, doi:10.1029/2007JG000435.

Copyright 2008 by the American Geophysical Union.