Key points are not available for this paper at this time.
Radiocarbon levels in annual plants provide a means to map out regional and continental‐scale fossil fuel plumes in surface air. We collected corn ( Zea mays ) across North America during the summer of 2004. Plants from mountain regions of western North America showed the smallest influence of fossil fuel‐derived CO 2 with a mean Δ 14 C of 66.3‰ ±1.7‰. Plants from eastern North America and from the Ohio‐Maryland region showed a larger fossil fuel influence with a mean Δ 14 C of 58.8‰ ± 3.9‰ and 55.2‰ ± 2.3‰, respectively, corresponding to 2.7 ppm ± 1.5 ppm and 4.3 ppm ± 1.0 ppm of added fossil fuel CO 2 relative to the mountain west. A model–data comparison suggests that surveys of annual plant Δ 14 C can provide a useful test of atmospheric mixing in transport models that are used to estimate the spatial distribution of carbon sources and sinks.
Hsueh et al. (Mon,) studied this question.