@Article{SawakuchiNWBVGCLDBKR:2017:CaDiEm,
               author = "Sawakuchi, Henrique O. and Neu, Vania and Ward, Nicholas D. and 
                         Barros, Maria de Lourdes C. and Val{\'e}rio, Aline de Matos and 
                         Gagne-Maynard, William and Cunha, Alan C. and Less, Diani F. da 
                         Silva and Diniz, Joel E. M. and Brito, Daimio C. and Krusche, Alex 
                         V. and Richey, Jeffrey E.",
          affiliation = "{Universidade de S{\~a}o Paulo (USP)} and {Universidade Federal 
                         Rural da Amaz{\^o}nia (UFRAM)} and {University of Florida} and 
                         {Universidade de S{\~a}o Paulo (USP)} and {Instituto Nacional de 
                         Pesquisas Espaciais (INPE)} and {University of Washington} and 
                         {Universidade Federal do Amap{\'a} (UFAP)} and {Universidade 
                         Federal do Amap{\'a} (UFAP)} and {Universidade Federal do 
                         Amap{\'a} (UFAP)} and {Universidade Federal do Amap{\'a} (UFAP)} 
                         and {Universidade de S{\~a}o Paulo (USP)} and {University of 
                         Washington}",
                title = "Carbon dioxide emissions along the lower Amazon River",
              journal = "Frontiers in Marine Science",
                 year = "2017",
               volume = "4",
                month = "Mar.",
             keywords = "CO2 emission, CO2 outgassing, GHG emission, Global CO2emission, 
                         Lower Amazon, River.",
             abstract = "A large fraction of the organic carbon derived from land that is 
                         transported through inland waters is decomposed along river 
                         systems and emitted to the atmosphere as carbon dioxide (CO2). The 
                         Amazon River outgasses nearly as much CO2 as the rainforest 
                         sequesters on an annual basis, representing ~25% of global CO2 
                         emissions from inland waters. However, current estimates of CO2 
                         outgassing from the Amazon basin are based on a conservative 
                         upscaling of measurements made in the central Amazon, meaning both 
                         basin and global scale budgets are likely underestimated. The 
                         lower Amazon River, from {\'o}bidos to the river mouth, 
                         represents ~13% of the total drainage basin area, and is not 
                         included in current basin-scale estimates. Here, we assessed the 
                         concentration and evasion rate of CO2 along the lower Amazon River 
                         corridor and its major tributaries, the Tapaj{\'o}s and Xingu 
                         Rivers. Evasive CO2 fluxes were directly measured using floating 
                         chambers and gas transfer coefficients (k600) were calculated for 
                         different hydrological seasons. Temporal variations in pCO2 and 
                         CO2 emissions were similar to previous observations throughout the 
                         Amazon (e.g., peak concentrations at high water) and CO2 
                         outgassing was lower in the clearwater tributaries compared to the 
                         mainstem. However, k600-values were higher than previously 
                         reported upstream likely due to the generally windier conditions, 
                         turbulence caused by tidal forces, and an amplification of these 
                         factors in the wider channels with a longer fetch. We estimate 
                         that the lower Amazon River mainstem emits 0.2 Pg C year-1 within 
                         our study boundaries, or as much as 0.48 Pg C year-1 if the entire 
                         spatial extent to the geographical mouth is considered. Including 
                         these values with updated basin scale estimates and estimates of 
                         CO2 outgassing from small streams we estimate that the Amazon 
                         running waters outgasses as much as 1.39 Pg C year-1, increasing 
                         the global emissions from inland waters by 43% for a total of 2.9 
                         Pg C year-1. These results highlight a large missing gap in 
                         basin-scale carbon budgets along the complete continuum of the 
                         Amazon River, and likely most other large river systems, that 
                         could drastically alter global scale carbon budgets.",
                  doi = "10.3389/fmars.2017.00076",
                  url = "http://dx.doi.org/10.3389/fmars.2017.00076",
                 issn = "2296-7745",
             language = "en",
           targetfile = "sawakuchi_carbon.pdf",
        urlaccessdate = "27 abr. 2024"
}