Transcom 3 inversion intercomparison: Model mean results for the estimation of seasonal carbon sources and sinks

• Main Authors: Gurney, Kevin Robert, Law, Rachel M., Denning, A. Scott, Rayner, Peter J., Pak, Bernard C., Baker, David, Bousquet, Philippe, Bruhwiler, Lori, Chen, Yu-Han, Ciais, Philippe, Fung, Inez Y., Heimann, Martin, John, Jasmin, Maki, Takashi, Maksyutov, Shamil, Peylin, Philippe, Prather, Michael, Taguchi, Shoichi
• Other Authors: Department of Atmospheric Science Fort Collins, Colorado State University Fort Collins (CSU), CSIRO Marine and Atmospheric Research Aspendale, Commonwealth Scientific and Industrial Research Organisation Canberra (CSIRO), Department of Earth System Science Irvine (ESS), University of California Irvine (UC Irvine), University of California (UC)-University of California (UC), National Center for Atmospheric Research Boulder (NCAR), Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Modélisation INVerse pour les mesures atmosphériques et SATellitaires (SATINV), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), NOAA Climate Monitoring and Diagnostics Laboratory (CMDL), National Oceanic and Atmospheric Administration (NOAA), Department of Earth, Atmospheric and Planetary Sciences MIT, Cambridge (EAPS), Massachusetts Institute of Technology (MIT), ICOS-ATC (ICOS-ATC), University of California Berkeley (UC Berkeley), University of California (UC), Max-Planck-Institut für Biogeochemie (MPI-BGC), Japan Meteorological Agency (JMA), Frontier Research System for Global Change (FRSGC), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Biogéochimie et écologie des milieux continentaux (Bioemco), École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Université Pierre et Marie Curie - Paris 6 (UPMC)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS), Modélisation des Surfaces et Interfaces Continentales (MOSAIC), National Institute of Advanced Industrial Science and Technology (AIST)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2004
• Subjects: carbon transport; inversion; [SDE.MCG]Environmental Sciences/Global Changes; Austral; Southern Ocean
• Online Access: https://hal-bioemco.ccsd.cnrs.fr/bioemco-00175985; https://hal-bioemco.ccsd.cnrs.fr/bioemco-00175985/document; https://hal-bioemco.ccsd.cnrs.fr/bioemco-00175985/file/2003GB002111.pdf

International audience The TransCom 3 experiment was begun to explore the estimation of carbon sources and sinks via the inversion of simulated tracer transport. We build upon previous TransCom work by presenting the seasonal inverse results which provide estimates of carbon flux for 11 land and 11 ocean regions using 12 atmospheric transport models. The monthly fluxes represent the mean seasonal cycle for the 1992 to 1996 time period. The spread among the model results is larger than the average of their estimated flux uncertainty in the northern extratropics and vice versa in the tropical regions. In the northern land regions, the model spread is largest during the growing season. Compared to a seasonally balanced biosphere prior flux generated by the CASA model, we find significant changes to the carbon exchange in the European region with greater growing season net uptake which persists into the fall months. Both Boreal North America and Boreal Asia show lessened net uptake at the onset of the growing season with Boreal Asia also exhibiting greater peak growing season net uptake. Temperate Asia shows a dramatic springward shift in the peak timing of growing season net uptake relative to the neutral CASA flux while Temperate North America exhibits a broad flattening of the seasonal cycle. In most of the ocean regions, the inverse fluxes exhibit much greater seasonality than that implied by the DeltapCO(2) derived fluxes though this may be due, in part, to misallocation of adjacent land flux. In the Southern Ocean, the austral spring and fall exhibits much less carbon uptake than implied by DeltapCO2 derived fluxes. Sensitivity testing indicates that the inverse estimates are not overly influenced by the prior flux choices. Considerable agreement exists between the model mean, annual mean results of this study and that of the previously published TransCom annual mean inversion. The differences that do exist are in poorly constrained regions and tend to exhibit compensatory fluxes in order to match the global ...