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	Provedor de dados ArchiMer (13) Autor Fromentin, Jean-marc (3) Cacho, Isabel (2) Deshayes, Julie (2) Arrizabalaga, Haritz (1) Arzel, Olivier (1) Ausin, Blanca (1) Barrier, Nicolas (1) Bauch, Henning A. (1) Boessenkool, K. P. (1) Bopp, Laurent (1) Briand, K (1) Calzelles, B (1) Cassou, Christophe (1) Cocco, Valentina (1) Cronin, Tm (1) Curry, Ruth (1) De Boisseson, Eric (1) Dunne, John P. (1) Dwyer, Gs (1) Elderfield, H. (1) Mais... Palavra-chave North Atlantic Oscillation (13) Climate variability (2) Holocene (2) 20th century climate (1) Albacore (1) Alboran Sea (1) Alkenone sea surface temperatures (1) Atlantic tuna (1) Atm (1) Atmosphere-ocean interaction (1) Black Sea (1) Bluefin (1) Carbon cycle (1) Circulation (1) Climate classification (1) Climate modeling (1) Climate models (1) Climatology (1) Coccolithophore productivity (1) Correlation coefficient (1) Mais... Tipo do documento Text (13) Ano 2020 (1) 2015 (1) 2014 (2) 2012 (2) 2008 (2) 2007 (1) 2005 (1) 2004 (1) 2003 (1) 2002 (1) Mais... País France (13) Idioma Inglês (13)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 13 Primeira ... 1 ... Última Atmospheric patterns driving Holocene productivity in the Alboran Sea (Western Mediterranean): A multiproxy approach ArchiMer Ausin, Blanca; Flores, Jose A.; Sierro, Francisco J.; Cacho, Isabel; Hernandez-almeida, Ivan; Martrat, Belen; Grimalt, Joan O.. High-resolution paleoproductivity variations have been reconstructed in a productive cell in the Alboran Sea for the Holocene. Fossil coccolithophore assemblages have been studied along with the U37 k' -estimated sea-surface temperature ( SST) and other paleoenvironmental proxies. The appearance of this cell is suggested at 7.7 ka cal. BP and was linked to the establishment of the western anti-cyclonic gyre. From that time until the present, the nannofossil accumulation rate of Florisphaera profunda has revealed successive episodes of weakening and strengthening of upwelling conditions in the Alboran Sea that have been simultaneous to changes in Western Mediterranean Deep Water ( WMDW) formation in the Gulf of Lions. A two-phase scenario operating at... Tipo: Text Palavras-chave: Alboran Sea; Coccolithophore productivity; Holocene; North Atlantic Oscillation; Western Mediterranean Deep Water. Ano: 2015 URL: https://archimer.ifremer.fr/doc/00351/46265/46054.pdf Can we detect the effects of environmental variations on fish populations through VPA outputs? the North Atlantic albacore case ArchiMer Kell, Laurence T; Fromentin, Jean-marc; Ortiz De Zarate, Victoria; Arrizabalaga, Haritz. Past studies have indicated that numbers-at-age 1 of albacore may be correlated with the winter NAO index in the previous year. Two main hypotheses have been stressed to explain such observation, i.e. an impact of the NAO on the recruitment or on migration patterns and consequently in the availability and catchability of specific age classes to the surface fishery. The objective of the present paper is to test whether such processes can be distinguished using VPA outputs. We first computed simple cross-correlations between the NAO at various lags, catches-at-age, Numbers-atage and F-at-age estimated in the last assessment. Since results were inconclusive, simulations were undertaken. The results showed that the probability of detecting spurious... Tipo: Text Palavras-chave: Thunnus alalunga; North Atlantic Oscillation; Simulation model; Virtual population analysis; Correlation coefficient; NAO. Ano: 2005 URL: http://archimer.ifremer.fr/doc/00194/30503/28913.pdf CMIP5 Model Intercomparison of Freshwater Budget and Circulation in the North Atlantic ArchiMer Deshayes, Julie; Curry, Ruth; Msadek, Rym. The subpolar North Atlantic is a center of variability of ocean properties, wind stress curl, and air-sea exchanges. Observations and hindcast simulations suggest that from the early 1970s to the mid-1990s the subpolar gyre became fresher while the gyre and meridional circulations intensified. This is opposite to the relationship of freshening causing a weakened circulation, most often reproduced by climate models. The authors hypothesize that both these configurations exist but dominate on different time scales: a fresher subpolar gyre when the circulation is more intense, at interannual frequencies (configuration A), and a saltier subpolar gyre when the circulation is more intense, at longer periods (configuration B). Rather than going into the detail of... Tipo: Text Palavras-chave: Atmosphere-ocean interaction; Freshwater; Climate models; Model comparison; Climate variability; North Atlantic Oscillation. Ano: 2014 URL: http://archimer.ifremer.fr/doc/00199/31024/29429.pdf Complex interplays among population dynamics, environmental forcing, and exploitation in fisheries ArchiMer Rouyer, Tristan; Fromentin, Jean-marc; Menard, Felix; Calzelles, B; Briand, K; Pianet, R; Planque, Benjamin; Stenseth, N. The patterns of variations in fisheries time series are known to result from a complex combination of species and fisheries dynamics all coupled with environmental forcing (including climate, trophic interactions, etc.). Disentangling the relative effects of these factors has been a major goal of fisheries science for both conceptual and management reasons. By examining the variability of 169 tuna and billfish time series of catch and catch per unit effort (CPUE) throughout the Atlantic as well as their linkage to the North Atlantic Oscillation (NAO), we find that the importance of these factors differed according to the spatial scale. At the scale of the entire Atlantic the patterns of variations are primarily spatially structured, whereas at a more... Tipo: Text Palavras-chave: Time series analysis; North Atlantic Oscillation; Atlantic tuna. Ano: 2008 URL: http://archimer.ifremer.fr/doc/2008/publication-3984.pdf Contributions of Atmospheric Stochastic Forcing and Intrinsic Ocean Modes to North Atlantic Ocean Interdecadal Variability ArchiMer Arzel, Olivier; Huck, Thierry. Atmospheric stochastic forcing associated with the North Atlantic Oscillation (NAO) and intrinsic ocean modes associated with the large-scale baroclinic instability of the North Atlantic Current (NAC) are recognized as two strong paradigms for the existence of the Atlantic Multidecadal Oscillation (AMO). The degree to which each of these factors contribute to the low-frequency variability of the North Atlantic is the central question in this paper. This issue is addressed here using an ocean general circulation model run under a wide range of background conditions extending from a super-critical regime where the oceanic variability spontaneously develops in the absence of any atmospheric noise forcing to a damped regime where the variability requires some... Tipo: Text Palavras-chave: Instability; Rossby waves; Climate variability; Interdecadal variability; Multidecadal variability; North Atlantic Oscillation. Ano: 2020 URL: https://archimer.ifremer.fr/doc/00599/71138/69452.pdf Interannual variability of the Subpolar Mode Water properties over the Reykjanes Ridge during 1990-2006 ArchiMer Thierry, Virginie; De Boisseson, Eric; Mercier, Herle. Combining hydrographic data from the OVIDE (Observatoire de la Variabilité Interannuelle à Decennale/Observatory of the Interannual to Decadal Variability) section (Greenland-Portugal) with Argo and historical CTD data over the period 1990–2006, we estimate the variability of the core properties of a variety of Subpolar Mode Water (SPMW) observed on the eastern flank of the Reykjanes Ridge. This SPMW acquires its core properties in the winter mixed layer along the eastern side of the Reykjanes Ridge. We find that the February sea surface temperature along the ridge is a proxy for its core temperature. The sources of this mode water are water masses advected by the mean cyclonic circulation in the Iceland Basin. A density compensated tendency for cooling... Tipo: Text Palavras-chave: North Atlantic Oscillation; Subpolar mode water; North Atlantic Ocean. Ano: 2008 URL: http://archimer.ifremer.fr/doc/2007/publication-3487.pdf Is the recruitment a key biological process in the hypothetical NAO-Atlantic tunas relationships? ArchiMer Fromentin, Jean-marc. In the recent past, it has been put forward that recruitment of the North Atlantic albacore, East Atlantic bluefin tuna and North Atlantic swordfish could be related to the North AtlanticOscillation (NAO). In this document, the biological processes behind the NAO/recruitmentrelationship are further investigated. Then, the possible relationship between the East Atlanticbluefin tuna recruitment was re-investigated. The linear relationship appeared to be only due to the low frequency signal, both BFT recruitment and NAO displaying a pseudo-cyclic upwardtrend, but year-to-year fluctuations were not synchronous. The superposed epoch analysis, thatwas conducted to test for possible non-linear and non-monotonous relationship did not reveal any clear connection.... Tipo: Text Palavras-chave: North Atlantic Oscillation; Recruitment; Bluefin; Albacore; Swordfish; Migration patterns; Time series; Spatially disaggregated data. Ano: 2002 URL: http://archimer.ifremer.fr/doc/00194/30498/28908.pdf Medieval Warm Period, Little Ice Age and 20th century temperature variability from Chesapeake Bay ArchiMer Cronin, Tm; Dwyer, Gs; Kamiya, T; Schwede, S; Willard, Da. We present paleoclimate evidence for rapid (< 100 years) shifts of similar to 2-4 degreesC in Chesapeake Bay (CB) temperature similar to 2100, 1600, 950, 650, 400 and 150 years before present (years BP) reconstructed from magnesium/calcium (Mg/Ca) paleothermometry. These include large temperature excursions during the Little Ice Age (similar to 1400-1900 AD) and the Medieval Warm Period (similar to 800-1300 AD) possibly related to changes in the strength of North Atlantic thermohaline circulation (THC). Evidence is presented for a long period of sustained regional and North Atlantic-wide warmth with low-amplitude temperature variability between similar to450. and 1000 AD. In addition to centennial-scale temperature shifts, the existence of numerous... Tipo: Text Palavras-chave: Paleoclimatology; Holocene; Medieval Warm Period; Little Ice Age; 20th century climate; North Atlantic Oscillation. Ano: 2003 URL: https://archimer.ifremer.fr/doc/00225/33648/32092.pdf North Atlantic climate and deep-ocean flow speed changes during the last 230 years ArchiMer Boessenkool, K. P.; Hall, I. R.; Elderfield, H.; Yashayaev, I.. Variations in the near-bottom flow speed of Iceland-Scotland Overflow Water (ISOW) are documented in a 230-year-long deep-sea sediment record from the eastern flank of Reykjanes Ridge in the subpolar North Atlantic at (sub) decadal time scales. For recent decades, the ISOW palaeocurrent reconstructions show similarities with observational hydrographic data. Furthermore, recent ISOW flow changes fall mostly within the range of its variability of the past 230 years. The record also reveals a hitherto unrecognized coupling of deep flow speeds in the subpolar North Atlantic with the North Atlantic Oscillation (NAO) index, with more (less) vigorous ISOW flow during negative (positive) phases of the NAO. Our results suggest that the changes in ISOW vigor are... Tipo: Text Palavras-chave: Deep ocean circulation; North Atlantic Oscillation; Drift sediments. Ano: 2007 URL: https://archimer.ifremer.fr/doc/00235/34646/33007.pdf On the forcing of sea level in the Black Sea ArchiMer Tsimplis, M. N.; Josey, S. A.; Rixen, M.; Stanev, E. V.. [1] Forcing mechanisms for sea level variability in the Black Sea are investigated in the [context of an observed increase in the sea level of this basin by 2.5 mm/yr over the last 60 years. Temperature and salinity variations computed from the Mediterranean Data Archeology and Rescue (MEDAR) data set exhibit significant interdecadal variability. However, the corresponding steric height variation does not show a long-term increase and thus cannot account for the observed change in sea level. The impact of surface freshwater flux (P-E) changes is also investigated using two independent data sets. The first data set, which is based on measurements collected in the basin, can explain most of the sea level variability, with only 0.8 mm/yr remaining... Tipo: Text Palavras-chave: Climatology; Steric sea level; North Atlantic Oscillation; Interbasin water and salt exchange; Black Sea. Ano: 2004 URL: https://archimer.ifremer.fr/doc/00209/32000/30424.pdf Response of North-Atlantic Ocean circulation to atmospheric weather regimes ArchiMer Barrier, Nicolas; Cassou, Christophe; Deshayes, Julie; Treguier, Anne-marie. A new framework is proposed for investigating the atmospheric forcing of North-Atlantic ocean circulation. Instead of using classical modes of variability, such as the North-Atlantic Oscillation (NAO) or the East-Atlantic Pattern, we here use the weather regimes paradigm. Using this framework we avoid problems associated with the assumptions of orthogonality and symmetry that are particular to modal analysis and known to be unsuitable for the NAO. Using ocean-only historical and sensitivity experiments, we investigate the impacts of the four winter weather regimes on horizontal and overturning circulations. Our results suggest that the Atlantic Ridge (AR), NAO− and NAO+ regimes induce a fast (monthly to interannual timescales) adjustment of the gyres via... Tipo: Text Palavras-chave: Circulation; Dynamics; Meridional overturning circulation; Atm; Ocean Structure; Phenomena; Gyres; North Atlantic Oscillation; Wind; Physical Meteorology and Climatology; Climate classification; Regimes; Models and modeling; Ocean models. Ano: 2014 URL: http://archimer.ifremer.fr/doc/00161/27258/25467.pdf The meridional temperature gradient in the eastern North Atlantic during MIS 11 and its link to the ocean-atmosphere system ArchiMer Kandiano, Evgenia S.; Bauch, Henning A.; Fahl, Kirsten; Helmke, Jan P.; Roehl, Ursula; Perez-folgado, Marta; Cacho, Isabel. Temporal and spatial patterns in eastern North Atlantic sea-surface temperatures (SST) were reconstructed for marine isotope stage (MIS) 11c using a submeridional transect of five sediment cores. The SST reconstructions are based on planktic foraminiferal abundances and alkenone indices, and are supported by benthic and planktic stable isotope measurements, as well as by ice-rafted debris content in polar and middle latitudes. Additionally, the larger-scale dynamics of the precipitation regime over northern Africa and the western Mediterranean region was evaluated from iron concentrations in marine sediments off NW Africa and planktic delta C-13 in combination with analysis of planktic foraminiferal abundances down to the species level in the Mediterranean... Tipo: Text Palavras-chave: Eastern North Atlantic; Stage 11; North Atlantic Oscillation; Foraminiferal sea surface temperatures; Alkenone sea surface temperatures. Ano: 2012 URL: https://archimer.ifremer.fr/doc/00265/37654/36976.pdf Variability of the Ocean Carbon Cycle in Response to the North Atlantic Oscillation ArchiMer Keller, Kathrin M.; Joos, Fortunat; Raible, Christoph C.; Cocco, Valentina; Froelicher, Thomas L.; Dunne, John P.; Gehlen, Marion; Bopp, Laurent; Orr, James C.; Tjiputra, Jerry; Heinze, Christoph; Segschneider, Joachim; Roy, Tilla; Metzl, Nicolas. Climate modes such as the North Atlantic Oscillation (NAO), representing internal variability of the climate system, influence the ocean carbon cycle and may mask trends in the sink of anthropogenic carbon. Here, utilising control runs of six fully coupled Earth System Models, the response of the ocean carbon cycle to the NAO is quantified. The dominating response, a seesaw pattern between the subtropical gyre and the subpolar Northern Atlantic, is instantaneous (<3 months) and dynamically consistent over all models and with observations for a range of physical and biogeochemical variables. All models show asymmetric responses to NAO+ and NAO− forcing, implying non-linearity in the connection between NAO and the ocean carbon cycle. However, model... Tipo: Text Palavras-chave: North Atlantic Oscillation; Carbon cycle; Ocean biogeochemistry; Climate modeling; Ocean-atmosphere interaction. Ano: 2012 URL: https://archimer.ifremer.fr/doc/00140/25166/23272.pdf Registros recuperados: 13 Primeira ... 1 ... Última

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