Peak growing season gross uptake of carbon in North America is largest in the Midwest USA

• Published in: Nature climate change Vol. 7; no. 6; pp. 450 - 454
• Main Authors: Hilton, Timothy W., Whelan, Mary E., Zumkehr, Andrew, Kulkarni, Sarika, Berry, Joseph A., Baker, Ian T., Montzka, Stephen A., Sweeney, Colm, Miller, Benjamin R., Elliott Campbell, J.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group 01.06.2017
• Subjects: Accuracy; Air monitoring; Carbon cycle; Carbon dioxide; Carbonyl sulfide; Carbonyls; Climate prediction; Computer simulation; Concentration gradient; Ecosystem models; Ecosystems; Environment models; Growing season; Information dissemination; Primary production; Regional analysis; Seasons; Sinkholes; Spatial variations; Sulfides; Sulphides; Tracers; Uncertainty; Uptake; North America
• ISSN: 1758-678X; 1758-6798
• DOI: 10.1038/nclimate3272

Gross primary production (GPP) is a first-order uncertainty in climate predictions. Large-scale CO2 observations can provide information about the carbon cycle, but are not directly useful for GPP. Recently carbonyl sulfide (COS or OCS) has been proposed as a potential tracer for regional and global GPP. Here we present the first regional assessment of GPP using COS. We focus on the North American growing season--a global hotspot for COS air-monitoring and GPP uncertainty. Regional variability in simulated vertical COS concentration gradients was driven by variation in GPP rather than other modelled COS sources and sinks. Consequently we are able to show that growing season GPP in the Midwest USA significantly exceeds that of any other region of North America. These results are inconsistent with some ecosystem models, but are supportive of new ecosystem models from CMIP6. This approach provides valuable insight into the accuracy of various ecosystem land models.