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Changes in ocean circulation and carbonate chemistry in the Australian sector of the Southern Ocean during the last 500,000 years ArchiMer
Sturm, Arne.
Stable oxygen and carbon isotope records and carbonate dissolution proxy records were used to reconstruct glacial/interglacial changes in ocean circulation, deep-water ventilation and carbonate chemistry in the Australian sector of the Southern Ocean for the last 500 kyr. Carbonate preservation records indicated a longitudinal gradient in Southern Ocean deep-water alkalinity at 110°E that persisted through glacial/interglacial stages. In contrast to previous studies suggesting the “Atlantic-type” carbonate preservation pattern in the entire Southern Ocean with enhanced carbonate preservation during interglacials and increased carbonate dissolution during glacials, this study, however, revealed that the reversed “Pacific-type” pattern of...
Tipo: Text Palavras-chave: Late Pleistocene; Southern Ocean; Deep-water circulation; Carbonate chemistry; Epibenthic delta13C; Carbonate dissolution; Surface-water circulation.
Ano: 2004 URL: https://archimer.ifremer.fr/doc/00499/61034/64441.pdf
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Climatological distributions of pH, pCO(2), total CO2, alkalinity, and CaCO3 saturation in the global surface ocean, and temporal changes at selected locations ArchiMer
Takahashi, Taro; Sutherland, S. C.; Chipman, D. W.; Goddard, J. G.; Ho, Cheng; Newberger, Timothy; Sweeney, Colm; Munro, D. R..
Climatological mean monthly distributions of pH in the total H+ scale, total CO2 concentration (TCO2), and the degree of CaCO3 saturation for the global surface ocean waters (excluding coastal areas) are calculated using a data set for pCO(2), alkalinity and nutrient concentrations in surface waters (depths <50 m), which is built upon the GLODAP, CARINA and LDEO databases. The mutual consistency among these measured parameters is demonstrated using the inorganic carbon chemistry model with the dissociation constants for carbonic acid by Lueker et al. (2000) and for boric acid by Dickson (1990). Linear potential alkalinity-salinity relationships are established for 24 regions of the global ocean. The mean monthly distributions of pH and carbon chemistry...
Tipo: Text Palavras-chave: Global ocean; Surface water; PH; Carbonate chemistry; Climatology; Seasonal and decadal change.
Ano: 2014 URL: https://archimer.ifremer.fr/doc/00290/40098/38796.pdf
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Factors regulating the Great Calcite Belt in the Southern Ocean and its biogeochemical significance ArchiMer
Balch, William M.; Bates, Nicholas R.; Lam, Phoebe J.; Twining, Benjamin S.; Rosengard, Sarah Z.; Bowler, Bruce C.; Drapeau, Dave T.; Garley, Rebecca; Lubelczyk, Laura C.; Mitchell, Catherine; Rauschenberg, Sara.
The Great Calcite Belt (GCB) is a region of elevated surface reflectance in the Southern Ocean (SO) covering similar to 16% of the global ocean and is thought to result from elevated, seasonal concentrations of coccolithophores. Here we describe field observations and experiments from two cruises that crossed the GCB in the Atlantic and Indian sectors of the SO. We confirm the presence of coccolithophores, their coccoliths, and associated optical scattering, located primarily in the region of the subtropical, Agulhas, and Subantarctic frontal regions. Coccolithophore-rich regions were typically associated with high-velocity frontal regions with higher seawater partial pressures of CO2 (pCO(2)) than the atmosphere, sufficient to reverse the direction of gas...
Tipo: Text Palavras-chave: Coccolithophores; Trace metals; Carbonate chemistry; Southern Ocean; Subantarctic Front; Subtropical Front.
Ano: 2016 URL: https://archimer.ifremer.fr/doc/00383/49412/49883.pdf
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Optimum satellite remote sensing of the marine carbonate system using empirical algorithms in the global ocean, the Greater Caribbean, the Amazon Plume and the Bay of Bengal ArchiMer
Land, Peter E.; Findlay, Helen S.; Shutler, Jamie D.; Ashton, Ian; Holding, Thomas; Grouazel, Antoine; Ardhuin, Fanny; Reul, Nicolas; Piolle, Jean-francois; Chapron, Bertrand; Quilfen, Yves; Bellerby, Richard G.j.; Bhadury, Punyasloke; Salisbury, Joseph; Vandemark, Douglas; Sabia, Roberto.
Improving our ability to monitor ocean carbonate chemistry has become a priority as the ocean continues to absorb carbon dioxide from the atmosphere. This long-term uptake is reducing the ocean pH; a process commonly known as ocean acidification. The use of satellite Earth Observation has not yet been thoroughly explored as an option for routinely observing surface ocean carbonate chemistry, although its potential has been highlighted. We demonstrate the suitability of using empirical algorithms to calculate total alkalinity (AT) and total dissolved inorganic carbon (CT), assessing the relative performance of satellite, interpolated in situ, and climatology datasets in reproducing the wider spatial patterns of these two variables. Both AT and CT in situ...
Tipo: Text Palavras-chave: Carbonate chemistry; Earth observation; Ocean acidification; Total alkalinity; Dissolved inorganic carbon; SMOS; Aquarius; CORA; HadGEM2-ES.
Ano: 2019 URL: https://archimer.ifremer.fr/doc/00591/70267/68368.pdf
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The Evolution of Deep Ocean Chemistry and Respired Carbon in the Eastern Equatorial Pacific Over the Last Deglaciation ArchiMer
De La Fuente, Maria; Calvo, Eva; Skinner, Luke; Pelejero, Carles; Evans, David; Mueller, Wolfgang; Povea, Patricia; Cacho, Isabel.
It has been shown that the deep Eastern Equatorial Pacific (EEP) region was poorly ventilated during the Last Glacial Maximum (LGM) relative to Holocene values. This finding suggests a more efficient biological pump, which indirectly supports the idea of increased carbon storage in the deep ocean contributing to lower atmospheric CO2 during the last glacial. However, proxies related to respired carbon are needed in order to directly test this proposition. Here we present Cibicides wuellerstorfi B/Ca ratios from Ocean Drilling Program Site 1240 measured by laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) as a proxy for deep water carbonate saturation state ([CO32-], and therefore [CO32-]), along with C-13 measurements. In addition, the...
Tipo: Text Palavras-chave: Marine carbon cycle; Carbonate chemistry; Ocean circulation; Glacial-interglacial cycles; Soft-tissue pump efficiency; Seafloor calcite dissolution.
Ano: 2017 URL: https://archimer.ifremer.fr/doc/00497/60824/64598.pdf
Registros recuperados: 5
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