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103. A 60000 year Greenland stratigraphic ice core chronology.

Author

Svensson, A., Andersen, K. K., Bigler, M., Clausen, H. B., Dahi-Jensen, D., Davies, S. M., Johnsen, S. J., Muscheler, R., Parrenin, F., Rasmussen, S. O., Röthlisberger, R., Seierstad, I., Steffensen, J. P., and Vinther, B. M.

Subjects
STRATIGRAPHIC geology, ICE cores, CHRONOLOGY, GLACIAL climates, CLIMATE change
Abstract

The Greenland Ice Core Chronology 2005 (GICC05) is a time scale based on annual layer counting of high-resolution records from Greenland ice cores. Whereas the Holocene part of the time scale is based on various records from the DYE-3, the GRIP, and the NorthGRIP ice cores, the glacial part is solely based on NorthGRIP records. Here we present an 18 ka extension of the time scale such that GICC05 continuously covers the past 60 ka. The new section of the time scale places the onset of Greenland Interstadial 12 (GI-12) at 46.9±1.0 ka b2k (before year AD 2000), the North Atlantic Ash Zone II layer in GI-15 at 55.4±1.2 ka b2k, and the onset of GI-17 at 59.4±1.3 ka b2k. The error estimates are derived from the accumulated number of uncertain annual layers. In the 40-60 ka interval, the new time scale has a discrepancy with the Meese-Sowers GISP2 time scale of up to 2.4 ka. Assuming that the Greenland climatic events are synchronous with those seen in the Chinese Hulu Cave speleothem record, GICC05 compares well to the time scale of that record with absolute age differences of less than 800 years throughout the 60 ka period. The new time scale is generally in close agreement with other independently dated records and reference horizons, such as the Laschamp geomagnetic excursion, the French Villars Cave and the Austrian Kleegruben Cave speleothem records, suggesting high accuracy of both event durations and absolute age estimates. [ABSTRACT FROM AUTHOR]

Published
2008
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104. A 60 000 year Greenland stratigraphic ice core chronology.

Author

Andersen, K. K., Bigler, M., Clausen, H. B., Dahl-Jensen, D., Johnsen, S. J., Rasmussen, S. O., Seierstad, I., Steffensen, J. P., Svensson, A., Vinther, B. M., Davies, S. M., Muscheler, R., Parrenin, F., and Röthlisberger, R.

Abstract

The Greenland Ice Core Chronology 2005 (GICC05) is a time scale based on annual layer counting of high-resolution records from Greenland ice cores. Whereas the Holocene part of the time scale is based on various records from the DYE-3, the GRIP, and the NorthGRIP ice cores, the glacial part is solely based on NorthGRIP records. Here we present an 18 kyr extension of the time scale such that GICC05 continuously covers the past 60 kyr. The new section of the time scale places the onset of Greenland Interstadial 12 (GI-12) at 46.9±1.0 kyr b2k (before year AD 2000), the North Atlantic Ash Zone 2 layer in GI-15 at 55.4±1.2 kyr b2k, and the onset of GI-17 at 59.4±1.3 kyr b2k. The error estimates are derived from the accumulated number of uncertain annual layers and can be regarded as 1σ uncertainties. In the 40-60 kyr interval the new time scale has a discrepancy with the Meese-Sowers GISP2 time scale of up to 2.4 kyr, whereas GICC05 compares well to the dating of the Hulu Cave record with absolute age differences of less than 800 years throughout the 60 kyr period. The new time scale is generally in close agreement with other independently dated records and reference horizons, such as the Laschamp geomagnetic excursion and the Kleegruben speleothem record from the Austrian Alps, suggesting high accuracy of both event durations and absolute age estimates. [ABSTRACT FROM AUTHOR]

Published
2007
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105. Two modes of glacial climate during the late stage 5 identified in Greenland ice core records.

Author

Siggaard-Andersen, M.-L., Ditlevsen, P. D., Hansen, A. Walløe, and Johnsen, S. J.

Abstract

From a detailed analysis of marine and terrestrial aerosol tracers in the NGRIP ice core we identified two distinct glacial atmospheric flow patterns. The climate transition from Marine Isotope Stage 5 (MIS 5) to MIS 4, at approximately 75 kyr BP, marks a shift between two different atmospheric flow regimes. Before this transition, during MIS 5d-a, the state of atmospheric flow was alternating between the two modes of different flow patterns, while a more persistent flow pattern was prevailing through the glacial period afterwards. These changes are accompanied by strong changes in an independent Greenland ice core proxy, namely the deuterium excess from the GRIP ice core, reflecting changes in the hydrological cycle and moisture source temperatures as well. The changes in atmospheric flow pattern are correlated with changed extent of ice-rafted detritus (IRD) deposition in the North Atlantic, indicating that the state of the atmospheric flow was highly sensitive to the waxing and waning of the Laurentide ice sheet. [ABSTRACT FROM AUTHOR]

Published
2007
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111. Treatment failure of direct oral anticoagulants in anti-phospholipid syndrome.

Author

Johnsen, S. J. A., Lauvsnes, M. B., Omdal, R., and Johnsen, Sja

Abstract

The article presents three case studies regarding the inefficacy of the use of dabigatran for prophylaxis of thromboembolismin patients with anti-phospholipid syndrome (APS). One of the women had two subsequent right-sided cerebral infarcts and was treted with dabigatran on suspicion of paroxysmal atrial fibrillation.

Published
2018
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112. Oxygen Isotope Profiles through the Antarctic and Greenland Ice Sheets

Author

JOHNSEN, S. J., DANSGAARD, W., CLAUSEN, H. B., and LANGWAY, C. C.

Abstract

The Camp Century, Greenland, deep ice core reveals seasonal variations in the isotopic composition of the ice back to 8,300 years BP. This is not the case for the Byrd Station, Antarctica, deep ice core. Both cores show long-term perturbations in isotopic composition reflecting climatic changes from before the beginning of the last glaciation. But the complexity of the glaciological regime at Byrd Station precludes a rational choice of a time scale. Pole-to-pole correlations of the palaeoclimatic data therefore become speculative except for the more pronounced features and general trends.

Published
1972
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115. A Deep Ice Core Drill System

Author

COPENHAGEN UNIV (DENMARK) GEOPHYSICAL ISOTOPE LAB*, Gundestrup,N. S., Johnsen,S. J., Reeh,N., COPENHAGEN UNIV (DENMARK) GEOPHYSICAL ISOTOPE LAB*, Gundestrup,N. S., Johnsen,S. J., and Reeh,N.

Abstract

This report describes the ice core drill system used to core to bedrock at a depth of 2037.63 m near Dye-3 in South Greenland (65 deg 11 N 43 deg 49'W h = 2490m). The drill is designed to provide good core quality and to be easy to maintain in the field. It is a probe type system, with the drill suspended on a 6.4 mm cable. The drill consists of two parts. An antitorque section prevents rotation of the upper part, containing the motors and the electronics. During drilling, the ice chips, produced by the cutters, are sucked into the lower, rotating part of the drill. The chips are transported inside the drill to the surface, where the drill is clamped to a 6 m tower and tilted to a horizontal position for easy core removal and drill cleaning. The cutters work like a plane, which reduces the cutting power and provides stable penetration, essentially independent of the load on the cutters. The drill is powered by a rechargeable battery pack, and is controlled by a microprocessor in the drill. The length and weight of the drill are 11.5 m and 180 kg, respectively., This article is from 'Proceedings of the International Workshop/Symposium on Ice Drilling Technology (2nd) Held at Calgary, Alberta, Canada on 30-31 August 1982,' AD-A156 733, p7-19.

Published
1984

117. Direct linking of Greenland and Antarctic ice cores at the Toba eruption (74 ka BP)

Author

Svensson, A., Bigler, M., Blunier, T., Clausen, H. B., Dahl-Jensen, D., Fischer, H., Fujita, S., Goto-Azuma, K., Johnsen, S. J., Kawamura, K., Kipfstuhl, S., Kohno, M., Parrenin, F., Popp, T., Rasmussen, S. O., Schwander, J., Seierstad, I., Severi, M., Steffensen, J. P., Udisti, R., Uemura, R., Vallelonga, P., Vinther, B. M., Wegner, A., Wilhelms, F., and Winstrup, M.

Subjects
13. Climate action
Abstract

The Toba eruption that occurred some 74 ka ago in Sumatra, Indonesia, is among the largest volcanic events on Earth over the last 2 million years. Tephra from this eruption has been spread over vast areas in Asia, where it constitutes a major time marker close to the Marine Isotope Stage 4/5 boundary. As yet, no tephra associated with Toba has been identified in Greenland or Antarctic ice cores. Based on new accurate dating of Toba tephra and on accurately dated European stalagmites, the Toba event is known to occur between the onsets of Greenland interstadials (GI) 19 and 20. Furthermore, the existing linking of Greenland and Antarctic ice cores by gas records and by the bipolar seesaw hypothesis suggests that the Antarctic counterpart is situated between Antarctic Isotope Maxima (AIM) 19 and 20. In this work we suggest a direct synchronization of Greenland (NGRIP) and Antarctic (EDML) ice cores at the Toba eruption based on matching of a pattern of bipolar volcanic spikes. Annual layer counting between volcanic spikes in both cores allows for a unique match. We first demonstrate this bipolar matching technique at the already synchronized Laschamp geomagnetic excursion (41 ka BP) before we apply it to the suggested Toba interval. The Toba synchronization pattern covers some 2000 yr in GI-20 and AIM- 19/20 and includes nine acidity peaks that are recognized in both ice cores. The suggested bipolar Toba synchronization has decadal precision. It thus allows a determination of the exact phasing of inter-hemispheric climate in a time interval of poorly constrained ice core records, and it allows for a discussion of the climatic impact of the Toba eruption in a global perspective. The bipolar linking gives no support for a long-term global cooling caused by the Toba eruption as Antarctica experiences a major warming shortly after the event. Furthermore, our bipolar match provides a way to place palaeoenvironmental records other than ice cores into a precise climatic context.

119. Rapid climate variability during warm and cold periods in polar regions and Europe [Variabilité climatique rapide pendant les périodes chaudes et froides aux pôles et en Europe]

Author

Masson-Delmotte, V., Landais, A., Combourieu-Nebout, N., von Grafenstein, U., Jouzel, J., Caillon, N., Chappellaz, J., Dahl-Jensen, D., Johnsen, S. J., and Stenni, B.

Subjects
climate change, polar region
Abstract

Typical rapid climate events punctuating the last glacial period in Greenland, Europe and Antarctica are compared to two rapid events occurring under warmer conditions: (i) Dansgaard-Oeschger event 25, the first abrupt warming occurring during last glacial inception; (ii) 8.2 ka BP event, the only rapid cooling recorded during the Holocene in Greenland ice cores and in Ammersee, Germany. The rate of warming during previous warmer interglacial periods is estimated from polar ice cores to 1.5 °C per millennium, without abrupt changes. Climate change expected for the 21st century should however be at least 10 times faster. © Académie des sciences. Published by Elsevier SAS. All rights reserved.

123. A Fast Light-Weight Core Drill

Author

Johnsen, S. J., primary, Dansgaard, W., additional, Gundestrup, N., additional, Hansen, S. B., additional, Nielsen, J. O., additional, and Reeh, N., additional

Published
1980
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138. Association of EBF1, FAM167A(C8orf13)-BLK and TNFSF4 gene variants with primary Sjögren's syndrome.

Author

Nordmark, G, Kristjansdottir, G, Theander, E, Appel, S, Eriksson, P, Vasaitis, L, Kvarnström, M, Delaleu, N, Lundmark, P, Lundmark, A, Sjöwall, C, Brun, J G, Jonsson, M V, Harboe, E, Gøransson, L G, Johnsen, S J, Söderkvist, P, Eloranta, M-L, Alm, G, and Baecklund, E

Subjects
*SJOGREN'S syndrome, *TUMOR necrosis factors, *NUCLEOTIDE sequence, *GENETIC polymorphisms, *GENETICS of disease susceptibility, *COHORT analysis
Abstract

We performed a candidate gene association study in 540 patients with primary Sjögren's Syndrome (SS) from Sweden (n=344) and Norway (n=196) and 532 controls (n=319 Swedish, n=213 Norwegian). A total of 1139 single-nucleotide polymorphisms (SNPs) in 84 genes were analyzed. In the meta-analysis of the Swedish and Norwegian cohorts, we found high signals for association between primary SS and SNPs in three gene loci, not previously associated with primary SS. These are the early B-cell factor 1 (EBF1) gene, P=9.9 × 10−5, OR 1.68, the family with sequence similarity 167 member A-B-lymphoid tyrosine kinase (FAM167A-BLK) locus, P=4.7 × 10−4, OR 1.37 and the tumor necrosis factor superfamily (TNFSF4=Ox40L) gene, P=7.4 × 10−4, OR 1.34. We also confirmed the association between primary SS and the IRF5/TNPO3 locus and the STAT4 gene. We found no association between the SNPs in these five genes and the presence of anti-SSA/anti-SSB antibodies. EBF1, BLK and TNFSF4 are all involved in B-cell differentiation and activation, and we conclude that polymorphisms in several susceptibility genes in the immune system contribute to the pathogenesis of primary SS. [ABSTRACT FROM AUTHOR]

Published
2011
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139. Abrupt change of Antarctic moisture origin at the end of Termination II.

Author

Masson-Delmotte, V., Stenni, B., Blunier, T., Cattani, O., Chappellaz, J., Cheng, H., Dreyfus, G., Edwards, R. L., Falourd, S., Govin, A., Kawamura, K., Johnsen, S. J., Jouzel, J., Landais, A., Lemieux-Dudon, B., Lourantou, A., Marshall, G., Minster, B., Mudelsee, M., and Pol, K.

Subjects
*ATMOSPHERIC temperature, *ATMOSPHERIC circulation, *CLIMATOLOGY, *ANTARCTIC ice
Abstract

The deuterium excess of polar ice cores documents past changes in evaporation conditions and moisture origin. New data obtained from the European Project for Ice Coring in Antarctica Dome C East Antarctic ice core provide new insights on the sequence of events involved in Termination II, the transition between the penultimate glacial and interglacial periods. This termination is marked by a north-south seesaw behavior, with first a slow methane concentration rise associated with a strong Antarctic temperature warming and a slow deuterium excess rise. This first step is followed by an abrupt north Atlantic warming, an abrupt resumption of the East Asian summer monsoon, a sharp methane rise, and a CO2 overshoot, which coincide within dating uncertainties with the end of Antarctic optimum. Here, we show that this second phase is marked by a very sharp Dome C centennial deuterium excess rise, revealing abrupt reorganization of atmospheric circulation in the southern Indian Ocean sector. [ABSTRACT FROM AUTHOR]

Published
2010
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140. Holocene thinning of the Greenland ice sheet.

Author

Vinther, B. M., Buchardt, S. L., Clausen, H. B., Dahl-Jensen, D., Johnsen, S. J., Fisher, D. A., Koerner, R. M., Raynaud, D., Lipenkov, V., Andersen, K. K., Blunier, T., Rasmussen, S. O., Steffensen, J. P., and Svensson, A. M.

Subjects
*ICE sheets, *GLOBAL warming, *CLIMATE change, *STABLE isotopes, *ICE cores, *ICE caps, *GLOBAL temperature changes, *GREENHOUSE effect, ENVIRONMENTAL aspects
Abstract

On entering an era of global warming, the stability of the Greenland ice sheet (GIS) is an important concern, especially in the light of new evidence of rapidly changing flow and melt conditions at the GIS margins. Studying the response of the GIS to past climatic change may help to advance our understanding of GIS dynamics. The previous interpretation of evidence from stable isotopes (δ18O) in water from GIS ice cores was that Holocene climate variability on the GIS differed spatially and that a consistent Holocene climate optimum—the unusually warm period from about 9,000 to 6,000 years ago found in many northern-latitude palaeoclimate records—did not exist. Here we extract both the Greenland Holocene temperature history and the evolution of GIS surface elevation at four GIS locations. We achieve this by comparing δ18O from GIS ice cores with δ18O from ice cores from small marginal icecaps. Contrary to the earlier interpretation of δ18O evidence from ice cores, our new temperature history reveals a pronounced Holocene climatic optimum in Greenland coinciding with maximum thinning near the GIS margins. Our δ18O-based results are corroborated by the air content of ice cores, a proxy for surface elevation. State-of-the-art ice sheet models are generally found to be underestimating the extent and changes in GIS elevation and area; our findings may help to improve the ability of models to reproduce the GIS response to Holocene climate. [ABSTRACT FROM AUTHOR]

Published
2009
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141. Asynchrony of Antarctic and Greenland climate change during the last glacial period.

Author

Blunier, T., Chappellaz, J., Schwander, J., Dällenbach, A., Stauffer, B., Stocker, T. F., Raynaud, D., Jouzel, J., Clausen, H. B., Hammer, C. U., and Johnsen, S. J.

Subjects
*CLIMATE change, *GLACIAL Epoch, *CLIMATOLOGY
Abstract

Reports on asynchrony of Antarctic and Greenland climate change during the last glacial period. A central issue in climate dynamics; The significance of a comparison of the global atmospheric concentration of methane as recorded in ice cores from Antarctica and Greenland; Suggestion that Antarctic climate change leads that of Greenland; Methods.

Published
1998
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142. Millennial and sub-millennial scale climatic variations recorded in polar ice cores over the last glacial period

Author

Valérie Masson-Delmotte, Markus Leuenberger, Hans Oerter, Sigfus J Johnsen, L. Loulergue, Dorthe Dahl-Jensen, Jérôme A Chappellaz, Barbara Stenni, D. Buiron, Hanno Meyer, Bénédicte Lemieux-Dudon, Amaelle Landais, Emilie Capron, Jean Jouzel, Adrian Schilt, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Glaces et Continents, Climats et Isotopes Stables (GLACCIOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), CLIPS, Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Climate and Environmental Physics [Bern] (CEP), Physikalisches Institut [Bern], Universität Bern [Bern] (UNIBE)-Universität Bern [Bern] (UNIBE), Centre for Ice and Climate [Copenhagen], Niels Bohr Institute [Copenhagen] (NBI), Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH)-Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH), Department of Bentho-pelagic processes, Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Dipartimento di Scienze Geologiche [Trieste], Università degli studi di Trieste = University of Trieste, European Project: 39423,FP6-SUSTDEV,EPICA-MIS, Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS), Universität Bern [Bern]-Universität Bern [Bern], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU)-Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU), Università degli studi di Trieste, Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Capron, E., Landais, A., Chappellaz, J., Schilt, A., Buiron, D., Dahl Jensen, D., Johnsen, S. J., Jouzel, J., Lemieux Dudon, B., Loulergue, L., Leuenberger, M., Masson Delmotte, V., Meyer, H., Oerter, H., and Stenni, Barbara

Subjects
nitrogen isotopes, 010504 meteorology & atmospheric sciences, Stratigraphy, Greenland, polar ice core, global warming, 01 natural sciences, Arctic, Ice core, Ice age, paleotemperature, Cryosphere, interstadial, lcsh:TD169-171.8, Glacial period, lcsh:Environmental sciences, lcsh:GE1-350, Global and Planetary Change, geography.geographical_feature_category, oxygen isotopes, Last Glacial, European Project for Ice Coring in Antarctica, polar ice cores, GRIP, Queen Maud Land, ice sheet, nitrogen isotope, Climatology, lcsh:TD172-193.5, sea level change, Geology, timescale, 010506 paleontology, lcsh:Environmental protection, paleotemperatures, lcsh:Environmental pollution, paleoclimate, oxygen isotope, millennial scale climatic variability, [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology, 0105 earth and related environmental sciences, geography, Dansgaard-Oeschger event, Paleontology, Dansgaard-Oeschger events, Antarctica, marine isotope stage, East Antarctica, Arctic ice pack, climate variation, Ice-sheet model, 13. Climate action, Ice sheet
Abstract

Since its discovery in Greenland ice cores, the millennial scale climatic variability of the last glacial period has been increasingly documented at all latitudes with studies focusing mainly on Marine Isotopic Stage 3 (MIS 3; 28–60 thousand of years before present, hereafter ka) and characterized by short Dansgaard-Oeschger (DO) events. Recent and new results obtained on the EPICA and NorthGRIP ice cores now precisely describe the rapid variations of Antarctic and Greenland temperature during MIS 5 (73.5–123 ka), a time period corresponding to relatively high sea level. The results display a succession of long DO events enabling us to highlight a sub-millennial scale climatic variability depicted by i) short-lived and abrupt warming events preceding some Greenland InterStadial (GIS) (precursor-type events) and ii) abrupt warming events at the end of some GIS (rebound-type events). The occurrence of these secondary events is suggested to be driven by the Northern Hemisphere summertime insolation at 65° N together with the internal forcing of ice sheets. Thanks to a recent NorthGRIP-EPICA Dronning Maud Land (EDML) common timescale over MIS 5, the bipolar sequence of climatic events can be established at millennial to sub-millennial timescale. This provides evidence that a linear relationship is not satisfactory in explaining the link between Antarctic warming amplitudes and the duration of their concurrent Greenland Stadial (GS) for the entire glacial period. The conceptual model for a thermal bipolar seesaw permits a reconstruction of the Antarctic response to the northern millennial and sub-millennial scale variability over MIS 5. However, we show that when ice sheets are extensive, Antarctica does not necessarily warm during the whole GS as the thermal bipolar seesaw model would predict.

Published
2018
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143. Abrupt change of Antarctic moisture origin at the end of Termination II

Author

Enricomaria Selmo, Jérôme Chappellaz, Gareth J. Marshall, Sigfus J Johnsen, Jean Jouzel, Claire Waelbroeck, Kenji Kawamura, Aline Govin, Bénédicte Minster, Barbara Stenni, Olivier Cattani, Richard Lawrence Edwards, Bénédicte Lemieux-Dudon, K. Pol, Amaelle Landais, Hai Cheng, Regine Röthlisberger, Manfred Mudelsee, S. Falourd, Anna Lourantou, Valérie Masson-Delmotte, Gabrielle Dreyfus, Thomas Blunier, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Glaces et Continents, Climats et Isotopes Stables (GLACCIOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Dipartimento di Scienze Geologiche [Trieste], Università degli studi di Trieste = University of Trieste, Centre for Ice and Climate [Copenhagen], Niels Bohr Institute [Copenhagen] (NBI), Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH)-Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH), CLIPS, Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Geology and Geophysics [Minnesota], University of Minnesota [Twin Cities] (UMN), University of Minnesota System-University of Minnesota System, Climat et Magnétisme (CLIMAG), National Institute of Polar Research [Tokyo] (NiPR), British Antarctic Survey (BAS), Natural Environment Research Council (NERC), Department of Bentho-pelagic processes, Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Climate Risk Analysis (CRAAM), Dipartimento di Scienze della Terra, Università degli studi di Parma = University of Parma (UNIPR), Paléocéanographie (PALEOCEAN), European Project: 39423,FP6-SUSTDEV,EPICA-MIS, Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), Università degli studi di Trieste, University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU)-Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS), University of Minnesota [Twin Cities], Università degli studi di Parma [Parme, Italie], Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), University of Parma = Università degli studi di Parma [Parme, Italie], Masson Delmotte, V., Stenni, Barbara, Blunier, T., Cattani, O., Chappellaz, J., Cheng, H., Dreyfus, G., Edwards, R. L., Falourd, S., Govin, A., Kawamura, K., Johnsen, S. J., Jouzel, J., Landais, A., Lemieux Dudon, B., Lourantou, A., Marshall, G. J., Minster, B., Mudelsee, M., Pol, K., Röthlisberger, R., Selmo, E., and Waelbroeck, C.

Subjects
Time Factors, deuterium excess, water stable isotopes, deglaciations, bipolar seesaw, site temperature, source temperature, polar ice cores, 010504 meteorology & atmospheric sciences, Paleoclimate, Climate, Greenland, 010502 geochemistry & geophysics, 01 natural sciences, atmospheric moisture, Westerlies, Ice core, deuterium exce, Glacial period, Atlantic Ocean, Indian Ocean, deuterium, water stable isotope, seasonal variation, Multidisciplinary, termination II, European Project for Ice Coring in Antarctica, methane, article, Temperature, interglacial, priority journal, Climatology, Physical Sciences, Interglacial, Seasons, Geology, Environmental Monitoring, warming, Atmospheric circulation, Climate Change, Climate change, Antarctic Regions, deglaciation, Paleoclimatology, [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology, 0105 earth and related environmental sciences, Ice, Last interglacial, carbon dioxide, 13. Climate action, Antarctica
Abstract

The deuterium excess of polar ice cores documents past changes in evaporation conditions and moisture origin. New data obtained from the European Project for Ice Coring in Antarctica Dome C East Antarctic ice core provide new insights on the sequence of events involved in Termination II, the transition between the penultimate glacial and interglacial periods. This termination is marked by a north–south seesaw behavior, with first a slow methane concentration rise associated with a strong Antarctic temperature warming and a slow deuterium excess rise. This first step is followed by an abrupt north Atlantic warming, an abrupt resumption of the East Asian summer monsoon, a sharp methane rise, and a CO 2 overshoot, which coincide within dating uncertainties with the end of Antarctic optimum. Here, we show that this second phase is marked by a very sharp Dome C centennial deuterium excess rise, revealing abrupt reorganization of atmospheric circulation in the southern Indian Ocean sector.

Published
2010
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144. The deuterium excess records of EPICA Dome C and Dronning Maud Land ice cores (East Antarctica)

Author

S. Falourd, E. Selmo, Paola Iacumin, Sigfus J Johnsen, Barbara Stenni, Jean Jouzel, Olivier Cattani, Bénédicte Minster, Valérie Masson-Delmotte, Hubertus Fischer, Regine Röthlisberger, Hanno Meyer, Hans Oerter, Roberto Udisti, George R. Hoffmann, Stenni, Barbara, Masson Delmotte, V., Selmo, E., Oerter, H., Meyer, H., Röthlisberger, R., Jouzel, J., Cattani, O., Falourd, S., Fischer, H., Hoffmann, G., Iacumin, P., Johnsen, S. J., Minster, B., Udisti, R., Department of Geological, Environmental and Marine Sciences [Trieste], Università degli studi di Trieste = University of Trieste, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Glaces et Continents, Climats et Isotopes Stables (GLACCIOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Oeschger Centre for Climate Change Research (OCCR), University of Bern, Università degli studi di Trieste, Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)

Subjects
Archeology, 010504 meteorology & atmospheric sciences, δ18O, ice cores, site temperature, 010502 geochemistry & geophysics, 01 natural sciences, Isotopes of oxygen, deuterium excess, oxygen isotopes, source temperature, East Antarctica, EPICA, calcium, sodium, EDML, EDC, Ice core, deuterium exce, oxygen isotope, Glacial period, Precipitation, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Ecology, Evolution, Behavior and Systematics, Holocene, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Global and Planetary Change, Geology, Glaciology, 13. Climate action, Climatology, Seawater, ice core
Abstract

New high-resolution deuterium excess (d) data from the two EPICA ice cores drilled in Dronning Maud Land (EDML) and Dome C (EDC) are presented here. The main moisture sources for precipitation at EDC and EDML are located in the Indian Ocean and Atlantic Ocean, respectively. The more southward moisture origin for EDML is reflected in a lower present-day d value, compared to EDC. The EDML and EDC isotopic records (δ18O and d) show the main climate features common to the East Antarctic plateau and similar millennial scale climate variability during the last glacial period. However, quite large δ18O and d differences are observed during MIS5.5 and the glacial inception with a long-term behaviour. A possibility for this long-term difference could be related to uncertainties in past accumulation rate which are used in the glaciological models. Regional climate anomalies between the two sites during MIS5.5 could also be consistent with the observed EDML-EDC δ18O and d gradient anomalies. Simulations performed with the General Circulation Model ECHAM4 for different time slices provide a temporal temperature/isotope slope for the EDML region in fair agreement to the modern spatial slope. Tsite and Tsource records are extracted from both ice cores, using a modelling approach, after corrections for past δ18O seawater and elevation changes. A limited impact of d on Antarctic temperature reconstruction at both EDML and EDC has been found with a higher impact only at glacial inception. The AIM (Antarctic Isotope Maximum) events in both ice cores are visible also after the source correction, suggesting that these are real climate features of the glacial period. The different shape of the AIM events between EDC and EDML, as well as some climate features in the early Holocene, points to a slightly different climate evolution at regional scale. A comparison of our temperature reconstruction profiles with the aerosol fluxes show a strong coupling of the nssCa fluxes with Antarctic temperatures during glacial period and a tighter coupling of δ18O and Tsite with ssNa flux at EDML compared to EDC during the glacial period and MIS5.5.

Published
2010
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145. Rapid climate variability during warm and cold periods in polar regions and Europe

Author

Sigfus J Johnsen, Nicolas Caillon, Ulrich von Grafenstein, Amaelle Landais, Nathalie Combourieu-Nebout, Jean Jouzel, Jérôme Chappellaz, Dorthe Dahl-Jensen, Valérie Masson-Delmotte, Barbara Stenni, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Glaces et Continents, Climats et Isotopes Stables (GLACCIOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institute of Earth Sciences, Hebrew University, Géochrononologie Traceurs Archéométrie (GEOTRAC), Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Geophysics and Water Resources, Section for Geology [Copenhagen], Department of Geosciences and Natural Resource Management [Copenhagen] (IGN), Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH)-Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH)-Department of Geosciences and Natural Resource Management [Copenhagen] (IGN), University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH), Dipartimento di Scienze Geologiche [Trieste], Università degli studi di Trieste = University of Trieste, European Commission, Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS), University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU)-Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU)-Department of Geosciences and Natural Resource Management [Copenhagen] (IGN), University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU), Università degli studi di Trieste, Masson Delmotte, V., Landais, A., Combourieu Nebout, N., von Grafenstein, U., Jouzel, J., Caillon, N., Chappellaz, J., Dahl Jensen, D., Johnsen, S. J., Stenni, Barbara, Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)

Subjects
010506 paleontology, 010504 meteorology & atmospheric sciences, Climate change, polar ice core, Palaeoclimate, 01 natural sciences, Lake, interglacials, Ice core, Dansgaard–Oeschger event, Rapid climate event, Glacial period, lake record, Holocene, 0105 earth and related environmental sciences, Global and Planetary Change, polar ice cores, Rapid climate events, Dansgaard–Oeschger events, Ice-sheet model, lake records, Settore GEO/08 - Geochimica e Vulcanologia, 13. Climate action, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, Climatology, Ice cores, Interglacial, Abrupt climate change, General Earth and Planetary Sciences, Polar, Pollen, Geology
Abstract

Typical rapid climate events punctuating the last glacial period in Greenland, Europe and Antarctica are compared to two rapid events occurring under warmer conditions: ( i ) Dansgaard–Oeschger event 25, the first abrupt warming occurring during last glacial inception; ( ii ) 8.2 ka BP event, the only rapid cooling recorded during the Holocene in Greenland ice cores and in Ammersee, Germany. The rate of warming during previous warmer interglacial periods is estimated from polar ice cores to 1.5 °C per millennium, without abrupt changes. Climate change expected for the 21st century should however be at least 10 times faster. To cite this article: V. Masson-Delmotte et al., C. R. Geoscience 337 (2005).

Published
2005
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146. A late-glacial high resolution site and source temperature record derived from the EPICA Dome C isotope records (East Antarctica)

Author

Olivier Cattani, Jean Jouzel, Barbara Stenni, Roland Souchez, Emiliano Castellano, Valérie Masson-Delmotte, Enricomaria Selmo, Antonio Longinelli, Regine Röthlisberger, S. Falourd, Jørgen Peder Steffensen, Sigfus J Johnsen, Roberto Udisti, Julian P. Sachs, Stenni, Barbara, Jouzel, J., Masson Delmotte, V., Röthlisberger, R., Castellano, E., Cattani, O., Falourd, S., Johnsen, S. J., Longinelli, A., Sachs, J. P., Selmo, E., Souchez, R., Steffensen, J. P., Udisti, R., Department of Geological, Environmental and Marine Sciences [Trieste], Università degli studi di Trieste, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Glaces et Continents, Climats et Isotopes Stables (GLACCIOS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), British Antarctic Survey (BAS), Natural Environment Research Council (NERC), Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Niels Bohr Institute [Copenhagen] (NBI), Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU), University of Parma = Università degli studi di Parma [Parme, Italie], Massachusetts Institute of Technology (MIT), Université libre de Bruxelles (ULB), Università degli studi di Trieste = University of Trieste, Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Firenze = University of Florence (UniFI), University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH), and Università degli studi di Parma = University of Parma (UNIPR)

Subjects
deuterium excess, deuterium, ice cores, site temperature, source temperature, East Antarctica, 010504 meteorology & atmospheric sciences, 010502 geochemistry & geophysics, Atmospheric sciences, 01 natural sciences, Ice core, Geochemistry and Petrology, Earth and Planetary Sciences (miscellaneous), deuterium exce, 14. Life underwater, Glacial period, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Temperature record, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Stable isotope ratio, Last Glacial Maximum, Sea surface temperature, Temperature gradient, Geophysics, Settore GEO/08 - Geochimica e Vulcanologia, 13. Climate action, Space and Planetary Science, Climatology, Seawater, ice core, Geology
Abstract

The timing and synchronisation of Greenland and Antarctic climate events that occurred during the last glacial period are still under debate, as is the magnitude of temperature change associated with these events. Here we present detailed records of local and moisture-source temperature changes spanning the period 27-45 kyr BP from water stable isotope measurements (deltaD and delta(18)O) in the recently drilled EPICA Dome C ice core, East Antarctic plateau. Using a simple isotopic model, site (DeltaT(site)) and source (DeltaT(source)) temperatures are extracted from the initial 50-yr high-resolution isotopic records, taking into account the changes in seawater isotopic composition. The deuterium isotope variability is very similar to the less precise deltaD record from the Vostok ice core, and the site temperature inversion leads to a temperature profile similar to the classical palaeothermometry method, due to compensations between source and ocean water corrections. The reconstructed DeltaT(site) and DeltaT(source) profiles show different trends during the glacial: the former shows a decreasing trend from the warm Al event (38 kyr BP) toward the Last Glacial Maximum, while the latter shows increasing values from 41 to 28 kyr BP. The low-frequency deuterium excess fluctuations are strongly influenced by obliquity fluctuations, controlling the low- to high-latitude temperature gradients, and show a remarkable similarity with a high-resolution southeast Atlantic sea surface temperature record. A comparison of the temperature profiles (site and source) and temperature gradient (DeltaT(source)-DeltaT(site)) with the non-sea-salt calcium and sodium records suggests a secondary influence of atmospheric transport changes on aerosol variations.

Published
2003
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147. A new 27 ky high resolution East Antarctic climate record

Author

Jean Jouzel, Jakob Schwander, V. Masson, Barbara Stenni, Antonio Longinelli, S. Falourd, Roland Souchez, Olivier Cattani, S. J. Johnsen, Nartsiss I. Barkov, J. P. Steffenssen, Michel Stievenard, J. R. Petit, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Glaces et Continents, Climats et Isotopes Stables (GLACCIOS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Géochrononologie Traceurs Archéométrie (GEOTRAC), Department of Geological, Environmental and Marine Sciences [Trieste], Università degli studi di Trieste, Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Università degli studi di Trieste = University of Trieste, Jouzel, J., Masson, V., Cattani, O., Falourd, S., Stievenard, M., Stenni, Barbara, Longinelli, A., Johnsen, S. J., Steffensen, J. P., Petit, J. R., Schwander, J., Souchez, R., and Barkov, N. I.

Subjects
010504 meteorology & atmospheric sciences, 530 Physics, 010502 geochemistry & geophysics, deglaciation, 01 natural sciences, Antarctic Cold Reversal, Paleontology, Ice core, Paleoclimatology, paleoclimate, Deglaciation, Glacial period, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, 0105 earth and related environmental sciences, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, geography, hydrogen isotopes, ice core, Antarctica, EPICA, geography.geographical_feature_category, European Project for Ice Coring in Antarctica, hydrogen isotope, Future sea level, Geophysics, Oceanography, 13. Climate action, Settore GEO/08 - Geochimica e Vulcanologia, General Earth and Planetary Sciences, Ice sheet, Geology
Abstract

International audience; The ice core recently drilled at the Dome Concordia site on the East Antarctic plateau provides a new high resolution isotope record covering part of the last glacial, the last transition and the Holocene. The two step shape of the deglaciation is remarkably similar for all the ice cores now available on the East Antarctic plateau. The first warming trend ends about 14000 years ago and is followed by the well marked Antarctic Cold Reversal (ACR) with a secondary peak common to all records. During the deglaciation, there are more similarities between the near coastal site of Taylor Dome and inland East Antarctica than between Taylor Dome and central Greenland. However, the results for EPICA do appear to confirm the Taylor Dome timescale after about 14 ka, showing cooling into the ACR roughly in phase between Greenland and Antarctica. While the overall deglacial pattem is asynchronous, this suggests that the now classical picture of a temperature seesaw between Antarctica and Greenland may be too simplistic. 1. Introduction Whereas numerous deep-sea, continental and ice core records covering the last deglaciation are now available [e.g. Alley and Clark, 1999], the driving mechanisms of this climatic transition are still not fully understood. Recent studies highlight the central role of the huge unstable Northern Hemisphere ice caps and their interaction with the oceanic thermohaline circulation in the North Atlantic. They also reveal that the Antarctic deglacial warming started before the sharp Greenland warming marking the onset of the B611ing and was interrupted by the so-called Antarctic Cold Reversal [hereafter ACR; Jouzel et al., 1995].

Published
2001
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148. Low Protein A20 in Minor Salivary Glands is Associated with Lymphoma in Primary Sjögren's Syndrome.

Author

Johnsen SJ, Gudlaugsson E, Skaland I, Janssen EA, Jonsson MV, Helgeland L, Berget E, Jonsson R, and Omdal R

Subjects
Adult, Aged, Aged, 80 and over, B-Lymphocytes immunology, Female, Germinal Center pathology, Humans, Immunohistochemistry, Lymphoma, B-Cell, Marginal Zone diagnosis, Male, Middle Aged, NF-kappa B metabolism, Sjogren's Syndrome diagnosis, Tumor Necrosis Factor alpha-Induced Protein 3, B-Lymphocytes metabolism, DNA-Binding Proteins metabolism, Intracellular Signaling Peptides and Proteins metabolism, Lymphoma, B-Cell, Marginal Zone epidemiology, Nuclear Proteins metabolism, Salivary Glands pathology, Sjogren's Syndrome epidemiology
Abstract

Patients with primary Sjögren's syndrome (pSS) have an increased risk of developing lymphomas, particularly the subtype mucosa-associated lymphoid tissue (MALT) lymphoma. Chronic antigen stimulation and increased activation of nuclear factor-κB (NF-κB) are important factors for the pathogenesis of MALT lymphomas. Protein A20 is an inhibitor of NF-κB. A recent study of pSS-associated MALT lymphomas identified potential functional abnormalities in the TNFAIP3 gene, which encodes protein A20. The present study aimed to assess protein A20 by immunohistochemistry (IHC) in minor salivary glands (MSGs) and lymphoma tissue sections of patients with pSS and investigate a potential association with lymphoma development. Protein A20 staining in lymphocytes was scored in four categories (0 = negative, 1 = weak, 2 = moderate and 3 = strong). For statistical purposes, these scores were simplified into negative (scores 0-1) and positive (scores 2-3). We investigated associations between protein A20-staining, focus scores, germinal centre (GC)-like structures and monoclonal B-cell infiltration in MSGs. MSG protein A20 staining was weaker in pSS patients with lymphomas than in those without lymphomas (P = 0.01). Weak protein A20 staining was also highly associated with a lack of GC formation (P < 0.01). Finally, weaker A20 staining was observed in the majority of pSS-associated MALT lymphoma tissues. In conclusion, we found absent or weak protein A20 immunoreactivity in MSGs of patients with pSS with lymphomas. This finding indicates that protein A20 downregulation in lymphocytes might be a mechanism underlying lymphoma genesis in patients with pSS., (© 2015 The Foundation for the Scandinavian Journal of Immunology.)

Published
2016
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149. Thrombotic microangiopathy and the antiphospholipid syndrome.

Author

Johnsen SJ, Valborgland T, Gudlaugsson E, Bostad L, and Omdal R

Subjects
Adult, Antiphospholipid Syndrome physiopathology, Female, Fingers pathology, Humans, Necrosis, Renal Insufficiency etiology, Renal Insufficiency pathology, Stomach Ulcer etiology, Stomach Ulcer pathology, Thrombotic Microangiopathies pathology, Urinary Bladder Diseases etiology, Urinary Bladder Diseases pathology, Antiphospholipid Syndrome complications, Thrombotic Microangiopathies etiology
Abstract

The antiphospholipid syndrome (APS) comprises the association between vascular thrombosis, including microthrombosis, pregnancy morbidity and the coexistence of anti-phospholipid antibodies. Thrombotic microangiopathy (TMA) can be one of the manifestations of the APS and may involve any organ. This feature of the APS is probably less recognized by clinical doctors than venous thrombosis and recurrent abortions. This case report presents a patient who developed a widespread TMA with renal failure, gastric mucosa ulceration, urinary bladder ulcerations and a finger necrosis as part of the APS.

Published
2010
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150. GRIP deuterium excess reveals rapid and orbital-scale changes in Greenland moisture origin.

Author

Masson-Delmotte V, Jouzel J, Landais A, Stievenard M, Johnsen SJ, White JW, Werner M, Sveinbjornsdottir A, and Fuhrer K

Abstract

The Northern Hemisphere hydrological cycle is a key factor coupling ice sheets, ocean circulation, and polar amplification of climate change. Here we present a Northern Hemisphere deuterium excess profile covering one climatic cycle, constructed with the use of delta18O and deltaD Greenland Ice Core Project (GRIP) records. Past changes in Greenland source and site temperatures are quantified with precipitation seasonality taken into account. The imprint of obliquity is evidenced in the site-to-source temperature gradient at orbital scale. At the millennial time scale, GRIP source temperature changes reflect southward shifts of the geographical locations of moisture sources during cold events, and these rapid shifts are associated with large-scale changes in atmospheric circulation.

Published
2005
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