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| Majkut, Joseph D.; Sarmiento, J. L.; Rodgers, K. B.. |
| Concerted community efforts have been devoted to producing an authoritative climatology of air-sea CO2 fluxes, but identifying decadal trends in CO2 fluxes has proven to be more challenging. The available surface pCO(2) estimates are too sparse to separate long-term trends from decadal and seasonal variability using simple linear models. We introduce Markov Chain Monte Carlo sampling as a novel technique for estimating the historical pCO(2) at the ocean surface. The result is a plausible history of surface pCO(2) based on available measurements and variability inferred from model simulations. Applying the method to a modern database of pCO(2) data, we find that two thirds of the ocean surface is trending toward increasing uptake of CO2, with a mean (year... |
| Tipo: Text |
Palavras-chave: Carbon; Assimilation; LDEO2010; Trend. |
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00290/40156/38724.pdf |
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| Ishii, M.; Feely, R. A.; Rodgers, K. B.; Park, G. -h.; Wanninkhof, R.; Sasano, D.; Sugimoto, H.; Cosca, C. E.; Nakaoka, S.; Telszewski, M.; Nojiri, Y.; Fletcher, S. E. Mikaloff; Niwa, Y.; Patra, P. K.; Valsala, V.; Nakano, H.; Lima, I.; Doney, S. C.; Buitenhuis, E. T.; Aumont, Olivier; Dunne, J. P.; Lenton, A.; Takahashi, T.. |
| Air-sea CO2 fluxes over the Pacific Ocean are known to be characterized by coherent large-scale structures that reflect not only ocean subduction and upwelling patterns, but also the combined effects of wind-driven gas exchange and biology. On the largest scales, a large net CO2 influx into the extratropics is associated with a robust seasonal cycle, and a large net CO2 efflux from the tropics is associated with substantial interannual variability. In this work, we have synthesized estimates of the net air-sea CO2 flux from a variety of products, drawing upon a variety of approaches in three sub-basins of the Pacific Ocean, i. e., the North Pacific extratropics (18-66 degrees N), the tropical Pacific (18 degrees S-18 degrees N), and the South Pacific... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00192/30320/28789.pdf |
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| Rödenbeck, C.; Bakker, D. C. E.; Gruber, N.; Iida, Y.; Jacobson, A. R.; Jones, S.; Landschützer, P.; Metzl, N.; Nakaoka, S.; Olsen, A.; Park, G.-h.; Peylin, P.; Rodgers, K. B.; Sasse, T. P.; Schuster, U.; Shutler, J. D.; Valsala, V.; Wanninkhof, R.; Zeng, J.. |
| Using measurements of the surface-ocean CO2 partial pressure (pCO2) and 14 different pCO2 mapping methods recently collated by the Surface Ocean pCO2 Mapping intercomparison (SOCOM) initiative, variations in regional and global sea–air CO2 fluxes have been investigated. Though the available mapping methods use widely different approaches, we find relatively consistent estimates of regional pCO2 seasonality, in line with previous estimates. In terms of interannual variability (IAV), all mapping methods estimate the largest variations to occur in the Eastern equatorial Pacific. Despite considerable spead in the detailed variations, mapping methods with closer match to the data also tend to be more consistent with each other. Encouragingly, this includes... |
| Tipo: Text |
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| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00293/40407/38967.pdf |
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| Ritter, R.; Landschuetzer, P.; Gruber, N.; Fay, A. R.; Iida, Y.; Jones, S.; Nakaoka, S.; Park, G. -h.; Peylin, P.; Roedenbeck, C.; Rodgers, K. B.; Shutler, J. D.; Zeng, J.. |
| The Southern Ocean (SO) carbon sink has strengthened substantially since the year 2000, following a decade of a weakening trend. However, the surface ocean pCO(2) data underlying this trend reversal are sparse, requiring a substantial amount of extrapolation to map the data. Here we use nine different pCO(2) mapping products to investigate the SO trends and their sensitivity to the mapping procedure. We find a robust temporal coherence for the entire SO, with eight of the nine products agreeing on the sign of the decadal trends, that is, a weakening CO2 sink trend in the 1990s (on average 0.22 0.24pgCyr(-1)decade(-1)), and a strengthening sink trend during the 2000s (-0.35 0.23pgCyr(-1)decade(-1)). Spatially, the multiproduct mean reveals rather uniform... |
| Tipo: Text |
Palavras-chave: Southern Ocean; CO2; Observations; SOCOM; Trends; Carbon sink. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00662/77387/79013.pdf |
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| Rodgers, K. B.; Aumont, Olivier; Fletcher, S. E. Mikaloff; Plancherel, Y.; Bopp, L.; De Boyer Montegut, Clement; Iudicone, D.; Keeling, R. F.; Madec, Gerard; Wanninkhof, R.. |
| Here we test the hypothesis that winds have an important role in determining the rate of exchange of CO2 between the atmosphere and ocean through wind stirring over the Southern Ocean. This is tested with a sensitivity study using an ad hoc parameterization of wind stirring in an ocean carbon cycle model, where the objective is to identify the way in which perturbations to the vertical density structure of the planetary boundary in the ocean impacts the carbon cycle and ocean biogeochemistry. Wind stirring leads to reduced uptake of CO2 by the Southern Ocean over the period 2000-2006, with a relative reduction with wind stirring on the order of 0.9 Pg C yr(-1) over the region south of 45 degrees S. This impacts not only the mean carbon uptake, but also the... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00211/32236/30684.pdf |
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