@Article{Erickson_JGR_20080315,
 author		= {David J. {Erickson III} and Richard T. Mills and Jay Gregg and T. J. Blasing and Forrest M. Hoffman and Robert J. Andres and Matthew Devries and Z. Zhu and S. R. Kawa},
 title		= {An Estimate of Monthly Global Emissions of Anthropogenic {CO$_2$}:  Impact on the Seasonal Cycle of Atmospheric {CO$_2$}},
 journal	= JGR,
 volume		= 113,
 number		= {G1},
 pages		= {G01023},
 doi		= {10.1029/2007JG000435},
 day		= 15,
 month		= mar,
 year		= 2008,
 abstract	= {Monthly estimates of the global emissions of anthropogenic CO$_2$ are presented. Approximating the seasonal CO$_2$ 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 CO$_2$ flux estimates are then used to model atmospheric CO$_2$ 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 CO$_2$ in and near those regions where anthropogenic CO$_2$ is released to the atmosphere. Local variations of 2--6~ppmv CO$_2$ 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 CO$_2$ emissions.}
}