Global-scale, seasonal carbon sources and sinks from the TransCom atmospheric inversion experiment

The seasonal sources and sinks of carbon from the TransCom 3 experiment will be presented. This phase of the experiment includes 12 different transport models or model variants. As with the annual mean results already published, northern extratropical terrestrial carbon uptake is distributed relatively evenly across the northern hemisphere. Compared to the neutral biosphere prior flux estimate (CASA simulation), the inverse results suggest both increased carbon uptake during the growing season and a lessened source outside of the growing season in Europe, Boreal Asia and Temperate North America. Flux estimates for Temperate Asia indicate an onset of carbon uptake earlier in the growing season than suggested by the neutral biosphere prior flux. In the Southern Ocean, uptake is lessened relative to the pCO2-based data, particularly during Austral Winter.