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| 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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| Trotta, Samantha; Marino, Maria; Maiorano, Patrizia; Girone, Angela. |
| High resolution quantitative analyses have been carried out on coccolithophore assemblages at the Ionian Sea core KC01B in the time interval crossing the deglaciation between Marine Isotope Stages 20 and 19 (Termination IX, in Lower-Middle Pleistocene). Principal Component Analysis emphasizes the temperature as the first environmental parameter affecting coccolithophore assemblages that reach a higher number of coccoliths per gram of sediment during the interglacial. Patterns of key taxa indicate the occurrence of a terminal stadial phase in the late MIS 20 when the presence of cold, turbid and low salinity surface waters in the Ionian Sea are highlighted by prominent peaks of Coccolithus pelagicus ssp. pelagicus, Gephyrocapsa muellerae >3 ƒÝm, and... |
| Tipo: Text |
Palavras-chave: Coccolithophores; Termination IX; Sapropel i-cycle 74; Lower-Middle Pleistocene. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00609/72069/70774.pdf |
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| Sanchez, Gloria E.; Lange, Carina B.; Flores, Jose-abel; Caniupan, Magaly; Lamy, Frank. |
| We present a new record of coccolithophore (coccoliths) export productivity for the past 30,000 years based on the study of a marine sediment core collected at the western entrance of the Strait of Magellan (Core MD07-3128; 53 degrees S, 75 degrees W). This sediment core revealed the presence of an assemblage composed by thirteen coccolithophore taxa, dominated by small Gephyrocapsa (> 80% of the total assemblage on the average) and accompanied, in less proportions (1-10%), by two morphotypes of Emiliana huxleyi, Coccolithus pelagicus and Calcidiscus leptoporus. Coccolith concentration and CaCO3 content were strongly correlated (P << 0.01; R-2 = 0.63). In general, both records were in phase with alkenone-derived sea-surface temperature (Caniupan... |
| Tipo: Text |
Palavras-chave: Coccolithophores; Last Glacial Maximum; Holocene; Southern Chile. |
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00289/40052/38797.pdf |
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| Terrats, L.; Claustre, H.; Cornec, M.; Mangin, A.; Neukermans, G.. |
| Coccolithophores (calcifying phytoplankton) form extensive blooms in temperate and subpolar oceans as evidenced from ocean‐color satellites. This study examines the potential to detect coccolithophore blooms with BioGeoChemical‐Argo (BGC‐Argo) floats, autonomous ocean profilers equipped with bio‐optical and physicochemical sensors. We first matched float data to ocean‐color satellite data of calcite concentration to select floats that sampled coccolithophore blooms. We identified two floats in the Southern Ocean, which measured the particulate beam attenuation coefficient (cp) in addition to two core BGC‐Argo variables, Chlorophyll‐a concentration ([Chl‐a]) and the particle backscattering coefficient (bbp). We show that coccolithophore blooms can be... |
| Tipo: Text |
Palavras-chave: Coccolithophores; Emiliania huxleyi; Bloom detection; BGC‐Argo floats; Bio‐optics; Global ocean. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00660/77209/78652.pdf |
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| Winter, Amos; Henderiks, Jorijntje; Beaufort, Luc; Rickaby, Rosalind E. M.; Brown, Christopher W.. |
| Coccolithophores are one of the most abundant eukaryotic phytoplankton in the oceans and are distinguished by their ability to build calcitic platelets (coccoliths). Of the numerous species, Emiliania huxleyi is considered one of the major calcifiers in the pelagic ocean. There is growing concern that increasing levels of CO2 in the atmosphere and the subsequent acidification of the ocean may disrupt the production of coccoliths. Furthermore, any change in the global distribution and abundance of E. huxleyi relative to non-calcifying groups of phytoplankton (e. g. diatoms) will have important effects on the biogeochemical cycling of carbon and climatic feedbacks. We review different lines of evidence that suggest E. huxleyi is increasingly expanding its... |
| Tipo: Text |
Palavras-chave: Coccolithophores; Biogeography; Poles; Geochemical cycling. |
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00292/40350/38929.pdf |
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| Amore, F. O.; Flores, J. A.; Voelker, A. H. L.; Lebreiro, S. M.; Palumbo, E.; Sierro, F. J.. |
| Changes in paleoclimate and paleoproductivity patterns have been identified by analysing, in conjunction with other available proxy data, the coccolithophore assemblages from core MD03-2699, located in the Portuguese margin in the time interval from the Marine Isotope Stage (MIS) 13/14 boundary to MIS 9 (535 to 300 ka). During the Mid-Brunhes event, the assemblages associated with the eccentricity minima are characterised by higher nannoplankton accumulation rate (NAR) values and by the blooming of the opportunistic genus Gephyrocapsa. Changes in coccolithophore abundance are also related to glacial-interglacial cycles. Higher NAR and numbers of coccoliths/g mainly occurred during the interglacial periods, while these values decreased during the glacial... |
| Tipo: Text |
Palavras-chave: North Atlantic Ocean; Mid-Pleistocene; Coccolithophores; Paleoclimate; Paleoproductivity. |
| Ano: 2012 |
URL: https://archimer.ifremer.fr/doc/00092/20286/17946.pdf |
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