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| Hatfield, Robert G.; Wheeler, Benjamin H.; Reilly, Brendan T.; Stoner, Joseph S.; Housen, Bernard A.. |
| We make fundamental observations of the particle size variability of magnetic properties from 71 core tops that span the southern Greenland and Norwegian Seas. These data provide the first detailed regional characterization of how bulk magnetic properties vary with sediment texture, sediment source, and sediment transport. Magnetic susceptibility (MS) and hysteresis parameters were measured on the bulk sediment and the five constituent sediment particle size fractions (clay, fine, medium, and coarse silt, and sand). The median MS value of the medium silt size fraction is ~3‐5 times higher than that of the sand and clay size fractions and results in a strong sensitivity of bulk MS to sediment texture. Hysteresis properties of the clay size fraction are... |
| Tipo: Text |
Palavras-chave: Northern Basaltic Province; Magnetic susceptibility; Nordic Seas; Magnetic grain size; Sediment source; Sediment transport. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00478/58998/61614.pdf |
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| Meland, My; Jansen, E; Elderfield, H; Dokken, Tm; Olsen, A; Bellerby, Rgj. |
| In core top samples in the Nordic Seas, Mg/Ca ratios of N. pachyderma ( sin.) are generally consistent with previous high-latitude calibration data but do not reflect the modern calcification temperature gradient from 2 degrees C in the northwest to 8 degrees C in the southeast. This is because Mg/Ca ratios in foraminiferal shells from the central Nordic Seas are similar to 0.4 mmol/mol higher than expected from calibrations of Nurnberg ( 1995) and Elderfield and Ganssen ( 2000). The enhanced Mg/Ca ratios are observed in an area with low sedimentation rates (< similar to 5 cm/kyr). Possible factors that may cause this include bioturbation, Holocene variability in old core tops, dissolution, pore water chemistry, occurrence of volcanic ash, and other... |
| Tipo: Text |
Palavras-chave: Planktonic foraminifera; N. pachyderma (sin.); Mg/Ca; Paleothermometry; Paleoceanography; Nordic Seas. |
| Ano: 2006 |
URL: https://archimer.ifremer.fr/doc/00234/34559/33319.pdf |
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| Risebrobakken, B; Jansen, E; Andersson, C; Mjelde, E; Hevroy, K. |
| High-resolution records from IMAGES core MD95-2011 in the eastern Norwegian Sea provide evidence for relatively large- and small-scale high-latitude climate variability throughout the Holocene. During the early and mid-Holocene a situation possibly driven by consistent stronger westerlies increased the eastward influence of Arctic intermediate and near-surface waters. For the late Holocene a relaxation of the atmospheric forcing resulted in increased influence of Atlantic water. The main changes in Holocene climate show no obvious connection to changing solar irradiance, and spectral analysis reveals no consistent signature for any periodic behavior of Holocene climate at millennial or centennial timescales. There are, however, indications of consistent... |
| Tipo: Text |
Palavras-chave: Holocene; Climate; Nordic Seas; NAO; High resolution; Variability. |
| Ano: 2003 |
URL: https://archimer.ifremer.fr/doc/00224/33500/32119.pdf |
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| Risebrobakken, Bjorg; Dokken, Trond; Ottera, Odd Helge; Jansen, Eystein; Gao, Yongqi; Drange, Helge. |
| About 115,000 yr ago the last interglacial reached its terminus and nucleation of new ice-sheet growth was initiated. Evidence from the northernmost Nordic Seas indicate that the inception of the last glacial was related to an intensification of the Atlantic Meridional Overturning Circulation (AMOC) in its northern limb. The enhanced AMOC, combined with minimum Northern hemisphere insolation, introduced a strong sea-land thermal gradient that, together with a strong wintertime latitudinal insolation gradient, increased the storminess and moisture transport to the high Northern European latitudes at a time when the Northern hemisphere summer insolation approached its minimum. |
| Tipo: Text |
Palavras-chave: Glacial inception; Nordic Seas; Northern European ice sheets; Palco-reconstruction; OGCM; AMOC; Insolation; Insolation gradient. |
| Ano: 2007 |
URL: https://archimer.ifremer.fr/doc/00233/34441/82768.pdf |
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| Lekens, W. A. H.; Sejrup, H. P.; Haflidason, H.; Knies, J.; Richter, T.. |
| [ 1] The timing of meltwater release in the southern Norwegian Sea in relation to millennial-scale climate variability is studied from core MD99-2283 based on down-core analysis of stable oxygen and carbon isotopes, calcium carbonate and ice-rafted debris (IRD). Between 20 and 40 calendar (cal) kyr B. P., strong Dansgaard-Oeschger cyclicity is expressed in increased carbonate content and reduced total organic carbon during warm interstadials and IRD marking the end of cold stadials. The planktonic delta(18)O record of core MD99-2283 compared to available isotopic records in the region confirms the existence of multisourced, synchronized meltwater anomalies during Heinrich ( H) events 2 to 4. It was found that the sudden release of meltwater occurs near... |
| Tipo: Text |
Palavras-chave: Meltwater; Nordic Seas; Heinrich events. |
| Ano: 2006 |
URL: https://archimer.ifremer.fr/doc/00234/34525/33431.pdf |
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| Sadatzki, Henrik; Maffezzoli, Niccolò; Dokken, Trond M.; Simon, Margit H; Berben, Sarah M. P.; Fahl, Kirsten; Kjær, Helle A.; Spolaor, Andrea; Stein, Ruediger; Vallelonga, Paul; Vinther, Bo M.; Jansen, Eystein. |
| Constraining the past sea ice variability in the Nordic Seas is critical for a comprehensive understanding of the abrupt Dansgaard-Oeschger (D-O) climate changes during the last glacial. Here we present unprecedentedly detailed sea ice proxy evidence from two Norwegian Sea sediment cores and an East Greenland ice core to resolve and constrain sea ice variations during four D-O events between 32 and 41 ka. Our independent sea ice records consistently reveal a millennial-scale variability and threshold response between an extensive seasonal sea ice cover in the Nordic Seas during cold stadials and reduced seasonal sea ice conditions during warmer interstadials. They document substantial and rapid sea ice reductions that may have happened within 250 y or... |
| Tipo: Text |
Palavras-chave: Sea ice; Nordic Seas; Dansgaard-Oeschger events; Abrupt climate change. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00659/77066/78374.pdf |
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| Andersen, C; Koc, N; Jennings, A; Andrews, Jt. |
| High-resolution sediment cores from the Voring Plateau, the North Iceland shelf, and the East Greenland shelf have been studied to investigate the stability of major surface currents in the Nordic Seas during the Holocene. Results from diatom assemblages and reconstructed sea-surface temperatures (SSTs) indicate a division of the Holocene into three periods: the Holocene Climate Optimum (9500 - 6500 calendar (cal) years BP), the Holocene Transition Period ( 6500 - 3000 cal years BP) and the Cool Late Holocene Period ( 3000 - 0 cal years BP). The overall climate development is in step with the decreasing insolation on the Northern Hemisphere, but regional differences occur regarding both timing and magnitude of SST changes. Sites under the direct influence... |
| Tipo: Text |
Palavras-chave: Nordic Seas; Holocene; Sea-surface temperatures. |
| Ano: 2004 |
URL: https://archimer.ifremer.fr/doc/00226/33721/32134.pdf |
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| Risebrobakken, Bjorg; Andersson, Carin; De Schepper, Stijn; Mcclymont, Erin L.. |
| The Pliocene (5.3-2.6Ma) is often described as a relatively stable climatic period, with warm temperatures characterizing high latitudes. New suborbital resolved stable isotope records from Ocean Drilling Program Hole 642B in the eastern Nordic Seas document that the Pliocene was not a stable period characterized by one climate. Rather, seven distinct climate phases, each lasting between 150,000 and 400,000years, are identified and characterized in the time interval 5.1-3.1Ma. Four of the transitions between the defined climate phases occurred close to an eccentricity minimum and a minimum in amplitude of change for Northern Hemisphere summer insolation, while two occurred around an eccentricity maximum and a maximum in amplitude in insolation change.... |
| Tipo: Text |
Palavras-chave: Pliocene; Nordic Seas; Stable isotopes; Diagenetic calcite; Paleogeography; External and internal forcing. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00504/61599/65864.pdf |
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