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| Zscheischler, Jakob; Mahecha, Miguel D.; Avitabile, Valerio; Calle, Leonardo; Carvalhais, Nuno; Ciais, Philippe; Gans, Fabian; Gruber, Nicolas; Hartmann, Jens; Herold, Martin; Ichii, Kazuhito; Jung, Martin; Landschuetzer, Peter; Laruelle, Goulven G.; Lauerwald, Ronny; Papale, Dario; Peylin, Philippe; Poulter, Benjamin; Ray, Deepak; Regnier, Pierre; Roedenbeck, Christian; Roman-cuesta, Rosa M.; Schwalm, Christopher; Tramontana, Gianluca; Tyukavina, Alexandra; Valentini, Riccardo; Van Der Werf, Guido; West, Tristram O.; Wolf, Julie E.; Reichstein, Markus. |
| Understanding the global carbon (C) cycle is of crucial importance to map current and future climate dynamics relative to global environmental change. A full characterization of C cycling requires detailed information on spatiotemporal patterns of surface-atmosphere fluxes. However, relevant C cycle observations are highly variable in their coverage and reporting standards. Especially problematic is the lack of integration of the carbon dioxide (CO2) exchange of the ocean, inland freshwaters and the land surface with the atmosphere. Here we adopt a data-driven approach to synthesize a wide range of observation-based spatially explicit surface-atmosphere CO2 fluxes from 2001 to 2010, to identify the state of today's observational opportunities and data... |
| Tipo: Text |
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| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00661/77322/78795.pdf |
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| Laruelle, Goulven G.; Landschutzer, Peter; Gruber, Nicolas; Tison, Jean-louis; Delille, Bruno; Regnier, Pierre. |
| In spite of the recent strong increase in the number of measurements of the partial pressure of CO2 in the surface ocean (pCO(2)), the air-sea CO2 balance of the continental shelf seas remains poorly quantified. This is a consequence of these regions remaining strongly under-sampled in both time and space and of surface p CO2 exhibiting much higher temporal and spatial variability in these regions compared to the open ocean. Here, we use a modified version of a two-step artificial neural network method (SOM-FFN; Landschutzer et al., 2013) to interpolate the p CO2 data along the continental margins with a spatial resolution of 0.25 ffi and with monthly resolution from 1998 to 2015. The most important modifications compared to the original SOM-FFN method are... |
| Tipo: Text |
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| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00662/77392/79004.pdf |
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| Laruelle, Goulven G.; Marescaux, Audrey; Le Gendre, Romain; Garnier, Josette; Rabouille, Christophe; Thieu, Vincent. |
| The Seine river discharges over 700 Gg of carbon (C) every year into the sea mostly under the form of dissolved inorganic carbon (DIC) and emits 445 Gg under the form of carbon dioxide (CO2) to the atmosphere over its entire river network. The watershed, which drains 76,000 km2, is heavily populated with 18 106 inhabitants and is thus submitted to large anthropic pressure. The offline coupling of two Reactive Transport Models is used to understand the complex spatial and temporal dynamics of carbon, oxygen and nutrients and quantify the CO2 exchange at the air-water interface along the main axis of the river. The estuarine section of the Seine is simulated by the generic estuarine model C-GEM (for Carbon Generic Estuarine Model), while the upstream part of... |
| Tipo: Text |
Palavras-chave: Dissolved inorganic and organic carbon; Carbon dioxide; Reactive-transport model; Seine river and estuary; Biogeochemical budget. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00493/60421/63858.pdf |
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| Laruelle, Goulven G.; Cai, Wei-jun; Hu, Xinping; Gruber, Nicolas; Mackenzie, Fred T.; Regnier, Pierre. |
| It has been speculated that the partial pressure of carbon dioxide (pCO(2)) in shelf waters may lag the rise in atmospheric CO2. Here, we show that this is the case across many shelf regions, implying a tendency for enhanced shelf uptake of atmospheric CO2. This result is based on analysis of long-term trends in the air-sea pCO(2) gradient (Delta pCO(2)) using a global surface ocean pCO(2) database spanning a period of up to 35 years. Using wintertime data only, we find that Delta pCO(2) increased in 653 of the 825 0.5 degrees cells for which a trend could be calculated, with 325 of these cells showing a significant increase in excess of + 0.5 mu atm yr(-1) (p < 0.05). Although noisier, the deseasonalized annual data suggest similar results. If this... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00673/78498/80777.pdf |
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| Regnier, Pierre; Friedlingstein, Pierre; Ciais, Philippe; Mackenzie, Fred T.; Gruber, Nicolas; Janssens, Ivan A.; Laruelle, Goulven G.; Lauerwald, Ronny; Luyssaert, Sebastiaan; Andersson, Andreas J.; Arndt, Sandra; Arnosti, Carol; Borges, Alberto V.; Dale, Andrew W.; Gallego-sala, Angela; Godderis, Yves; Goossens, Nicolas; Hartmann, Jens; Heinze, Christoph; Ilyina, Tatiana; Joos, Fortunat; Larowe, Douglas E.; Leifeld, Jens; Meysman, Filip J. R.; Munhoven, Guy; Raymond, Peter A.; Spahni, Renato; Suntharalingam, Parvadha; Thullner, Martin. |
| A substantial amount of the atmospheric carbon taken up on land through photosynthesis and chemical weathering is transported laterally along the aquatic continuum from upland terrestrial ecosystems to the ocean. So far, global carbon budget estimates have implicitly assumed that the transformation and lateral transport of carbon along this aquatic continuum has remained unchanged since pre-industrial times. A synthesis of published work reveals the magnitude of present-day lateral carbon fluxes from land to ocean, and the extent to which human activities have altered these fluxes. We show that anthropogenic perturbation may have increased the flux of carbon to inland waters by as much as 1.0 Pg C yr(-1) since pre-industrial times, mainly owing to enhanced... |
| Tipo: Text |
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| Ano: 2013 |
URL: https://archimer.ifremer.fr/doc/00264/37508/36764.pdf |
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| Landschuetzer, Peter; Laruelle, Goulven G.; Roobaert, Alizee; Regnier, Pierre. |
| In this study, we present the first combined open- and coastal-ocean pCO(2) mapped monthly climatology (Landschutzer et al., 2020b, https://doi.org/10.25921/qb25-f418, https://www.nodc.noaa.gov/ocads/oceans/MPI-ULB-SOM_FFN_clim.html, last access: 8 April 2020) constructed from observations collected between 1998 and 2015 extracted from the Surface Ocean CO2 Atlas (SOCAT) database. We combine two neural network-based pCO(2) products, one from the open ocean and the other from the coastal ocean, and investigate their consistency along their common overlap areas. While the difference between open- and coastal-ocean estimates along the overlap area increases with latitude, it remains close to 0 mu atm globally. Stronger discrepancies, however, exist on the... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00676/78823/81149.pdf |
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| Laruelle, Goulven G.; Lauerwald, Ronny; Pfeil, Benjamin; Regnier, Pierre. |
| Over the past decade, estimates of the atmospheric CO2 uptake by continental shelf seas were constrained within the 0.18-0.45 Pg C yr(-1) range. However, most of those estimates are based on extrapolations from limited data sets of local flux measurements (n<100). Here we propose to derive the CO2 air-sea exchange of the shelf seas by extracting 310(6) direct surface ocean CO2 measurements from the global database SOCAT (Surface Ocean CO2 Atlas), atmospheric CO2 values from GlobalVIEW and calculating gas transfer rates using readily available global temperature, salinity, and wind speed fields. We then aggregate our results using a global segmentation of the shelf in 45 units and 152 subunits to establish a consistent regionalized CO2 exchange budget at... |
| Tipo: Text |
Palavras-chave: CO2; Coastal ocean; Carbon cycle. |
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00293/40426/38969.pdf |
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