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| Registros recuperados: 36 | |
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| Bittig, Henry C.; Maurer, Tanya L.; Plant, Joshua N.; Schmechtig, Catherine; Wong, Annie P. S.; Claustre, Hervé; Trull, Thomas W.; Udaya Bhaskar, T. V. S.; Boss, Emmanuel; Dall’olmo, Giorgio; Organelli, Emanuele; Poteau, Antoine; Johnson, Kenneth S.; Hanstein, Craig; Leymarie, Edouard; Le Reste, Serge; Riser, Stephen C.; Rupan, A. Rick; Taillandier, Vincent; Thierry, Virginie; Xing, Xiaogang. |
| The Biogeochemical-Argo program (BGC-Argo) is a new profiling-float-based, ocean wide, and distributed ocean monitoring program which is tightly linked to, and has benefited significantly from, the Argo program. The community has recommended for BGC-Argo to measure six additional properties in addition to pressure, temperature and salinity measured by Argo, to include oxygen, pH, nitrate, downwelling light, chlorophyll fluorescence and the optical backscattering coefficient. The purpose of this addition is to enable the monitoring of ocean biogeochemistry and health, and in particular, monitor major processes such as ocean deoxygenation, acidification and warming and their effect on phytoplankton, the main source of energy of marine ecosystems. Here we... |
| Tipo: Text |
Palavras-chave: Ocean observation; Ocean biogeochemical cycles; Sensors; Carbon cycle; Ocean optics; Best practices; Argo. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00512/62344/66607.pdf |
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| Bittig, Henry C.; Steinhoff, Tobias; Claustre, Harve; Fiedler, Bjoern; Williams, Nancy L.; Sauzede, Raphaelle; Koertzinger, Arne; Gattuso, Jean-pierre. |
| This work presents two new methods to estimate oceanic alkalinity (A(T)), dissolved inorganic carbon (C-T), pH, and pCO(2) from temperature, salinity, oxygen, and geolocation data. "CANYON-B" is a Bayesian neural network mapping that accurately reproduces GLODAPv2 bottle data and the biogeochemical relations contained therein. "CONTENT" combines and refines the four carbonate system variables to be consistent with carbonate chemistry. Both methods come with a robust uncertainty estimate that incorporates information from the local conditions. They are validated against independent GO-SHIP bottle and sensor data, and compare favorably to other state-of-the-art mapping methods. As "dynamic climatologies" they show comparable performance to classical... |
| Tipo: Text |
Palavras-chave: Carbon cycle; GLODAP; Marine carbonate system; Surface pCO(2) climatology; Revelle buffer factor increase; Machine learning; Nutrient estimation. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00675/78681/80879.pdf |
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| Touratier, Franck; Goyet, C; Coatanoan, Christine; Andrie, C. |
| With a limited number of properties (salinity, temperature, total dissolved inorganic carbon, total alkalinity, and oxygen) from a recent cruise in the tropical Atlantic Ocean, We use the simple and recent approach TrOCA (Tracer combining Oxygen, inorganic Carbon, and total Alkalinity) to estimate the distribution of anthropogenic CO2 along three latitudinal sections. In order to assess the quality of the anthropogenic CO2 distribution, results from the method are compared to the CFC-11 measurements. We discuss the large-scale distribution of the main water masses of the tropical Atlantic Ocean in the light of the anthropogenic CO2 and the CFC-11 distributions. Keeping in mind that the anthropogenic CO2 emission began similar to 60 years earlier than that... |
| Tipo: Text |
Palavras-chave: Tropical belt; Atlantic Ocean; Water mass; Carbon cycle. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-886.pdf |
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| Skinner, L. C.; Freeman, E.; Hodell, D.; Waelbroeck, C.; Vazquez Riveiros, Natalia; Scrivner, A.e. |
| Changes in ocean ventilation, controlled by both overturning rates and air‐sea gas exchange, are thought to have played a central role in atmospheric CO2 rise across the last deglaciation. Here we constrain the nature of Atlantic Ocean ventilation changes over the last deglaciation using radiocarbon and stable carbon isotopes from two depth transects in the Atlantic basin. Our findings broadly cohere with the established pattern of deglacial Atlantic overturning change, and underline the existence of active northern sourced deep‐water export at the Last Glacial Maximum (LGM). We find that the western Atlantic was less affected by incursions of southern‐sourced deep water, as compared to the eastern Atlantic, despite both sides of the basin being strongly... |
| Tipo: Text |
Palavras-chave: Air‐ Sea exchange; AMOC; Carbon cycle; Deglaciation; Radiocarbon; Ventilation. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00665/77717/79810.pdf |
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| Dufresne, J-l.; Foujols, M-a.; Denvil, S.; Caubel, A.; Marti, O.; Aumont, Olivier; Balkanski, Y.; Bekki, S.; Bellenger, H.; Benshila, R.; Bony, S.; Bopp, L.; Braconnot, P.; Brockmann, P.; Cadule, P.; Cheruy, F.; Codron, F.; Cozic, A; Cugnet, D.; De Noblet, N.; Duvel, J-p.; Ethe,; Fairhead, L.; Fichefet, T.; Flavoni, S.; Friedlingstein, P.; Grandpeix, J-y.; Guez, L.; Guilyardi, E.; Hauglustaine, D.; Hourdin, F.; Idelkadi, A.; Ghattas, J.; Joussaume, S.; Kageyama, M.; Krinner, G.; Labetoulle, S.; Lahellec, A.; Lefebvre, M; Lefevre, F.; Levy, C.; Li, Zhanbin; Lloyd, J.; Lott, F.; Madec, G.; Mancip, M.; Marchand, M; Masson, S.; Meurdesoif, Y.; Mignot, J.; Musat, I.; Parouty, S.; Polcher, J.; Rio, C; Schulz, M.; Swingedouw, D.; Szopa, S.; Talandier, Claude; Terray, P.; Viovy, N.; Vuichard, N.. |
| We present the global general circulation model IPSL-CM5 developed to study the long-term response of the climate system to natural and anthropogenic forcings as part of the 5th Phase of the Coupled Model Intercomparison Project (CMIP5). This model includes an interactive carbon cycle, a representation of tropospheric and stratospheric chemistry, and a comprehensive representation of aerosols. As it represents the principal dynamical, physical, and bio-geochemical processes relevant to the climate system, it may be referred to as an Earth System Model. However, the IPSL-CM5 model may be used in a multitude of configurations associated with different boundary conditions and with a range of complexities in terms of processes and interactions. This paper... |
| Tipo: Text |
Palavras-chave: Climate; Climate change; Climate projections; Earth System Model; CMIP5; CMIP3; Greenhouse gases; Aerosols; Carbon cycle; Allowable emissions; RCP scenarios; Land use changes. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00138/24966/23079.pdf |
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| Thevenon, Florian; Williamson, David; Bard, Edouard; Anselmetti, Flavio S.; Beaufort, Luc; Cachier, Helene. |
| This paper addresses the quantification of combustion-derived products in oceanic and continental sediments by optical and chemical approaches, and the interest of combining such methods for reconstructing past biomass burning activity and the pyrogenic carbon cycle. In such context, the dark particles >0.2 mu m(2) remaining after the partial digestion of organic matter are optically counted by automated image analysis and defined as charcoal, while the elemental carbon remaining after thermal and chemical oxidative treatments is quantified as black carbon (BC). The obtained pyrogenic carbon records from three sediment core-based case studies, (i) the Late Pleistocene equatorial Pacific Ocean. (ii) the mid-Holocene European Lake Lucerne, and (iii) the... |
| Tipo: Text |
Palavras-chave: Biomass burning; Carbon cycle; Charcoal; Black carbon; Climate; Human impact. |
| Ano: 2010 |
URL: https://archimer.ifremer.fr/doc/00231/34198/32764.pdf |
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| Montalvo, J. F.; García, I.; Esponda, S.C.,; Cesar, M.E.; Alburquerque, O.. |
| Se realizaron cinco muestreos entre enero de 2007 y junio de 2008 a la zona costera del municipio Playa, con el fin de evaluar los contenidos de los compuestos del ciclo del carbono. Los parámetros estudiados en la matriz agua fueron carbón orgánico, pH, alcalinidad total, alcalinidad al carbonato, dióxido de carbono total, dióxido de carbono libre, presión parcial de CO2, y contenidos de bicarbonato y carbonato. Los compuestos de carbono orgánico e inorgánico tuvieron una distribución muy heterogénea, los valores de pH (8,24±0,22) y alcalinidad total (2523±119 μmol/kg) indican que el área tiene un comportamiento alcalino, estos montos fueron similares a los encontrados en aguas de la plataforma marina cubanos y superiores a los consignados para el... |
| Tipo: Journal Contribution |
Palavras-chave: Carbon dioxide; Alkalinity; Carbon cycle; Carbon dioxide; Alkalinity; Carbon cycle; Http://aims.fao.org/aos/agrovoc/c_1302; Http://aims.fao.org/aos/agrovoc/c_8721; Http://aims.fao.org/aos/agrovoc/c_17299. |
| Ano: 2009 |
URL: http://hdl.handle.net/1834/3390 |
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| Lourantou, Anna; Metzl, Nicolas. |
| The fate of the Southern Ocean atmospheric CO(2) sink is under question. Here we assess seasonal to decadal changes of surface fCO(2) within an extended sink area along the track between Kerguelen and Amsterdam islands in the subantarctic zone. Data from 17 oceanographic cruises were used, from 1991 to 2011 and two distinct regions were examined, separated by the Subantarctic Front (SAF). The region south of the SAF displays a strong summer phytoplankton bloom of up to -28 mmol C m(-2) d(-1) within a calm area, constrained by physics and topography. On an annual basis, this region is a 6-fold more important sink than that deduced from Takahashi climatology, highlighting the importance of key-areas separate examination before proceeding to spatial... |
| Tipo: Text |
Palavras-chave: Kerguelen; Air-sea CO2 fluxes; Carbon cycle; Frontal region; Island mass effect; Subantarctic zone. |
| Ano: 2011 |
URL: https://archimer.ifremer.fr/doc/00144/25557/23706.pdf |
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| Bertoni, R. |
| The radiochemical methods proposed for evaluating heterotrophic activity in waters have been severely criticized in recent years because they are not considered to be sufficiently realistic. Thus, the possibility of directly measuring the heterotrophic consumption of naturally occurring Organic Carbon (OC) in fresh water samples incubated under controlled conditions has been evaluated. The analytical performances of two OC analyzers utilizable for this purpose are discussed here, and some examples of the results obtained by the direct measurement of OC consumption are presented. The consumption rates thus measured ranged from 11.6 to 50.2 mu gC/ 1.h. Although the technique discussed here is less sensitive than radiochemical methods, the few assumptions... |
| Tipo: Text |
Palavras-chave: Biogeochemistry; Microbiology; Carbon cycle; Organic carbon; Water; Heterotrophic organisms; Analytical techniques. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-950.pdf |
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| Mckinley, Galen A.; Fay, Amanda R.; Eddebbar, Yassir A.; Gloege, Lucas; Lovenduski, Nicole S.. |
| The ocean has absorbed the equivalent of 39% of industrial‐age fossil carbon emissions, significantly modulating the growth rate of atmospheric CO2 and its associated impacts on climate. Despite the importance of the ocean carbon sink to climate, our understanding of the causes of its interannual‐to‐decadal variability remains limited. This hinders our ability to attribute its past behavior and project its future. A key period of interest is the 1990s, when the ocean carbon sink did not grow as expected. Previous explanations of this behavior have focused on variability internal to the ocean or associated with coupled atmosphere/ocean modes. Here, we use an idealized upper ocean box model to illustrate that two external forcings are sufficient to explain... |
| Tipo: Text |
Palavras-chave: Carbon cycle; Ocean carbon sink; Forced; Internal. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00676/78775/80950.pdf |
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| Carmack, E. C.; Yamamoto-kawai, M.; Haine, T. W. N.; Bacon, S.; Bluhm, B. A.; Lique, Camille; Melling, H.; Polyakov, I. V.; Straneo, F.; Timmermans, M. -l.; Williams, W. J.. |
| The Arctic Ocean is a fundamental node in the global hydrological cycle and the ocean's thermohaline circulation. We here assess the system's key functions and processes: 1) the delivery of fresh and low salinity waters to the Arctic Ocean by river inflow, net precipitation, distillation during the freeze/thaw cycle and Pacific Ocean inflows; 2) the disposition (e.g. sources, pathways and storage) of freshwater components within the Arctic Ocean; and 3) the release and export of freshwater components into the bordering convective domains of the North Atlantic. We then examine physical, chemical or biological processes which are influenced or constrained by the local quantities and geochemical qualities of fresh water; these include: stratification and... |
| Tipo: Text |
Palavras-chave: Arctic; Oceans; Circulation; Freshwater; Carbon cycle; Acidification. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00313/42460/41831.pdf |
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| Morita, R; Jones, R. |
| The nitrifying bacteria were found to survive 24 weeks in the absence of ammonium without decreasing their number of cell size. Because H sub(2), CO, and CH sub(4) are present in the marine environment, these substrates were investigated as a possible source of the energy of maintenance for the nitrifying bacteria. super(14)CO and super(14)CH sub(4) were found to be oxidized by the nitrifiers. N-serve was found to inhibit the oxidation of CO. Using the nitrifiers' ability to oxide CO, a method for the determination of the nitrification rate was developed. The ability of nitrifiers to oxidize CO may play a significant role in the cycling of CO sub(2) in the marine environment. Whether CO and CH sub(4) oxidation play a role in the survival of nitrifiers in... |
| Tipo: Text |
Palavras-chave: Methane; Carbon dioxide; Survival; Bacteria; Nitrification; Nitrogen cycle; Oxidation; Carbon cycle; Biogeochemistry; Metabolism. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-975.pdf |
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| Faust, Johan C.; Tessin, Allyson; Fisher, Ben J.; Zindorf, Mark Sebastian; Papadaki, Sonia; Hendry, Katharine R.; Doyle, Katherine A.; März, Christian. |
| Burial of organic material in marine sediments represents a dominant natural mechanism of long-term carbon sequestration globally, but critical aspects of this carbon sink remain unresolved. Investigation of surface sediments led to the proposition that on average 10-20% of sedimentary organic carbon is stabilised and physically protected against microbial degradation through binding to reactive metal (e.g. iron and manganese) oxides. Here we examine the long-term efficiency of this rusty carbon sink by analysing the chemical composition of sediments and pore waters from four locations in the Barents Sea. Our findings show that the carbon-iron coupling persists below the uppermost, oxygenated sediment layer over thousands of years. We further propose that... |
| Tipo: Text |
Palavras-chave: Carbon cycle; Geochemistry. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00675/78755/80923.pdf |
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| Watson, Andrew J.; Metzl, Nicolas; Schuster, Ute. |
| The oceans are an important sink for anthropogenically produced CO2, and on time scales longer than a century they will be the main repository for the CO2 that humans are emitting. Our knowledge of how ocean uptake varies (regionally and temporally) and the processes that control it is currently observation-limited. Traditionally, and based on sparse observations and models at coarse resolution, ocean uptake has been thought to be relatively invariant. However, in the few places where we have enough observations to define the uptake over periods of many years or decades, it has been found to change substantially at basin scales, responding to indices of climate variability. We illustrate this for three well-studied regions: the equatorial Pacific, the... |
| Tipo: Text |
Palavras-chave: CO2; Carbon cycle; Greenhouse gases; Atmospheric oxygen. |
| Ano: 2011 |
URL: https://archimer.ifremer.fr/doc/00144/25561/23702.pdf |
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| Registros recuperados: 36 | |
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