Consulta: creatorFacets:"Rossignol, L."
Registros recuperados: 6
Data/hora: 15/06/2024 18:24:59

Stratification of surface waters during the last glacial millennial climatic events: a key factor in subsurface and deep-water mass dynamics
Provedor de dados: 5
Autores: Wary, M.; Eynaud, F.; Sabine, M.; Zaragosi, S.; Rossignol, L.; Malaize, B.; Palis, E.; Zumaque, J.; Caulle, C.; Penaud, A.; Michel, E.; Charlier, K.
The last glacial period was punctuated by abrupt climatic events with extrema known as Heinrich and Dansgaard–Oeschger events. These millennial events have been the subject of many paleoreconstructions and model experiments in the past decades, but yet the hydrological processes involved remain elusive. In the present work, high-resolution analyses were conducted on the 12–42 ka BP section of core MD99-2281 retrieved southwest of the Faeroe Islands, and combined with analyses conducted in two previous studies (Zumaque et al., 2012; Caulle et al., 2013). Such a multiproxy approach, coupling micropaleontological, geochemical and sedimentological analyses, allows us to track surface, subsurface, and deep hydrological processes occurring during these rapid...
Tipo: Text
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00296/40767/39770.pdf

A 1.2 Ma record of glaciation and fluvial discharge from the West European Atlantic margin
Provedor de dados: 5
Autores: Toucanne, Samuel; Zaragosi, S.; Bourillet, Jean-francois; Gibbard, P. L.; Eynaud, F.; Giraudeau, J.; Turon, J. L.; Cremer, M.; Cortijo, E.; Martinez, P.; Rossignol, L.
The correlation of continental sedimentary records with the marine isotope stratigraphy is a challenge of central importance in Quaternary stratigraphy, particularly in Western Europe where long records of glaciation on land areas are particularly rare. Here we demonstrate for the first time the interrelationship of events during the last 1.2 Ma in an ocean-sediment core from the Bay of Biscay (NE Atlantic), SW of the Channel. The identification of discharge variations from tributary river systems to the 'Fleuve Manche' palaeoriver during glacio-eustatic sea-level lowstands demonstrates the correlation of the marine sediment stratigraphy to the expansion and recession of the European ice-sheets. The amplitude and chronology of European ice-sheet...
Tipo: Text
Palavras-chave: Middle pleistocene transition; Ice sheet dynamics; Sea level; Climate change; North Atlantic; English channel; Heinrich events; Fleuve manche; Deep; Origin.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6956.pdf

Assessment of sea surface temperature changes in the Gulf of Cadiz during the last 30 ka: implications for glacial changes in the regional hydrography
Provedor de dados: 5
Autores: Penaud, Aurelie; Eynaud, F.; Voelker, A.; Kageyama, M.; Marret, F.; Turon, J. L.; Blamart, D.; Mulder, T.; Rossignol, L.
New dinocyst analyses were conducted on core MD99-2339 retrieved from the central Gulf of Cadiz. Dinocyst and foraminiferal assemblages from this core are combined with existing data off SW Portugal and NW Morocco to investigate past hydrological and primary productivity regimes in the subtropical NE Atlantic Ocean over the last 30 ka. Our results have revealed highest upwelling intensity during Heinrich Stadial 1 (HS 1) and the Younger Dryas and weaker upwelling cells during the Last Glacial Maximum (LGM) and HS 2, off the SW Iberian and NW Moroccan margins. Similar assemblages between the Gulf of Cadiz and the NW Moroccan margin, and distinct species off Portugal, were observed during the cold climatic extremes that punctuated the last 30 ka. This...
Tipo: Text
Ano: 2011
URL: https://archimer.ifremer.fr/doc/00230/34125/32598.pdf

Monsoon-driven Saharan dust variability over the past 240,000 years
Provedor de dados: 5
Autores: Skonieczny, C.; Mcgee, D.; Winckler, G.; Bory, A.; Bradtmiller, L. I.; Kinsley, C. W.; Polissar, P. J.; De Pol-holz, R.; Rossignol, L.; Malaizé, B.
Reconstructions of past Saharan dust deposition in marine sediments provide foundational records of North African climate over time scales of 103 to 106 years. Previous dust records show primarily glacial-interglacial variability in the Pleistocene, in contrast to other monsoon records showing strong precessional variability. Here, we present the first Saharan dust record spanning multiple glacial cycles obtained using 230Th normalization, an improved method of calculating fluxes. Contrary to previous data, our record from the West African margin demonstrates high correlation with summer insolation and limited glacial-interglacial changes, indicating coherent variability in the African monsoon belt throughout the late Pleistocene. Our results demonstrate...
Tipo: Text
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00474/58554/61106.pdf

High-latitude obliquity as a dominant forcing in the Agulhas current system
Provedor de dados: 5
Autores: Caley, T.; Kim, J-h; Malaize, B.; Giraudeau, J.; Laepple, T.; Caillon, N.; Charlier, K.; Rebaubier, H.; Rossignol, L.; Castaneda, I. S.; Schouten, S.; Damste, J. S. Sinninghe.
The Agulhas Current transport of heat and salt from the Indian Ocean into the South Atlantic around South Africa (Agulhas leakage), can affect the Atlantic meridional overturning circulation (AMOC) and, thus, influence global climate. However, efforts to elucidate forcing mechanisms connecting the Agulhas leakage with the upstream dynamics of the current have been hampered by a lack of climate records extracted from the area where the Agulhas current originates. We determine 800-kyr sea surface temperature (SST) and salinity (SSS) records from the "precursor" region of the Agulhas current and show that these records contain strong 100-kyr and 41-kyr cycles. This latter obliquity-driven cycle is nearly in phase with changes in the annual mean insolation and...
Tipo: Text
Ano: 2011
URL: https://archimer.ifremer.fr/doc/00228/33904/32363.pdf

Southern Hemisphere imprint for Indo-Asian summer monsoons during the last glacial period as revealed by Arabian Sea productivity records
Provedor de dados: 5
Autores: Caley, Thibaut; Zaragosi, S.; Bourget, Julien; Martinez, P.; Malaize, B.; Eynaud, F.; Rossignol, L.; Garlan, Thierry; Ellouz-zimmermann, Nadine.
The monsoon is one of the most important climatic phenomena: it promotes inter-hemispheric exchange of energy and affects the economical prosperity of several countries exposed to its seasonal seesaw. Previous studies in both the Indian and Asian monsoon systems have generally suggested a dominant northern hemispheric (NH) control on summer monsoon dynamics at the scale of suborbital-millennial climatic changes, while the forcing/response of Indian and Asian monsoons at the orbital scale remains a matter of debate. Here, six marine sediment cores distributed across the whole Arabian Sea are used to build a regional surface marine productivity signal. The productivity signal is driven by the intensity of Indian summer monsoon winds. Our results demonstrate...
Tipo: Text
Ano: 2013
URL: https://archimer.ifremer.fr/doc/00274/38492/36962.pdf