Author: "Barbara Stenni" - Searchworks@Jio Institute Digital Library Search Results

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157 results on '"Barbara Stenni"'

51. Drought-induced dieback of

Author: Tadeja, Savi, Valentino, Casolo, Anna, Dal Borgo, Sabine, Rosner, Valentina, Torboli, Barbara, Stenni, Paolo, Bertoncin, Stefano, Martellos, Alberto, Pallavicini, and Andrea, Nardini
Subjects: carbon metabolism, water status, rooting depth, parasitic diseases, fungi, food and beverages, Black pine, drought, plastome, Research Article
Abstract: Extreme summer droughts induced differential impacts in a population of Pinus nigra trees. We analyzed eventual physiological differences between desiccated and healthy trees. Desiccated trees were more vulnerable to drought-induced xylem embolism, and were also suffering from depletion of carbohydrate reserves. Our data suggest that genotypic or phenotypic intraspecific variability can play fundamental roles in defining individual drought responses/impacts, dictating the fate of single trees under global-change-type droughts., Ongoing climate change is apparently increasing tree mortality rates, and understanding mechanisms of drought-induced tree decline can improve mortality projections. Differential drought impact on conspecific individuals within a population has been reported, but no clear mechanistic explanation for this pattern has emerged. Following a severe drought (summer 2012), we monitored over a 3-year period healthy (H) and declining (D) Pinus nigra trees co-occurring in a karstic woodland to highlight eventual individual-specific physiological differences underlying differential canopy dieback. We investigated differences in water and carbon metabolism, and xylem anatomy as a function of crown health status, as well as eventual genotypic basis of contrasting drought responses. H and D trees exploited the same water pools and relied on similar hydraulic strategies to cope with drought stress. Genetic analyses did not highlight differences between groups in terms of geographical provenance. Hydraulic and anatomical analyses showed conflicting results. The hydraulic tracheid diameter and theoretical hydraulic conductivity were similar, but D trees were characterized by lower water transport efficiency, greater vulnerability to xylem conduit implosion and reduced carbohydrate stores. Our results suggest that extreme drought events can have different impacts on conspecific individuals, with differential vulnerability to xylem embolism likely playing a major role in setting the fate of trees under climate change.
Published: 2018

52. A new Eemian record of Antarctic tephra layers retrieved from the Talos Dome ice core (Northern Victoria Land)

Author: Antonio Langone, Jean-Robert Petit, Biancamaria Narcisi, Barbara Stenni, Ente per le Nuove Technologie, l'Energia e l'Ambiente (ENEA), Centro Ricerche Casaccia, Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Observatoire des Sciences de l'Univers de Grenoble (OSUG ), 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 Grenoble Alpes [2016-2019] (UGA [2016-2019])-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 Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS), IGG-CNR, Dipartimento di Scienze Geologiche [Trieste], Università degli studi di Trieste, 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), and Narcisi, B.
Subjects: 010504 meteorology & atmospheric sciences, Antarctic ice core, Population, 010502 geochemistry & geophysics, Oceanography, Last Interglacial, 01 natural sciences, Antarctic ice cores, Glass shard microanalysis, Northern Victoria Land volcanism, Tephra layers, Tephrostratigraphy, Paleontology, Glass shard microanalysis Tephrostratigraphy, Ice core, Glacial period, education, Tephra, 0105 earth and related environmental sciences, Global and Planetary Change, education.field_of_study, geography, Eemian, geography.geographical_feature_category, Settore GEO/08 - Geochimica e Vulcanologia, 13. Climate action, [SDE]Environmental Sciences, Interglacial, Glass shard microanalysi, Ice sheet, Quaternary, Geology
Abstract: International audience; Polar ice sheets are remarkable repositories of tephra layers. The Talos Dome ice core (72°49′S, 159°11′E), drilled at the edge of the East Antarctic Plateau, close to Late Quaternary volcanoes, offers considerable potential to extend the current tephra time-stratigraphic framework. A tephrochronological study was undertaken of the ice core sections related to the Last Interglacial and the transition to the subsequent glacial period. Thirteen macroscopically visible layers, interpreted to be related to primary deposition of fallout tephra, have been analysed for quantitative grain size and glass shard geochemistry. The layers, precisely framed within the climate (δ18O) record for the core, span in age from 111.6 ± 1.9 to 123.3 ± 2.2 ka. Coarse particle size suggests origin from regional sources. Indeed, the vast majority of the samples display an alkaline affinity and trachytic composition that are both typical geochemical features of rifting Antarctic volcanism. Using subtle differences in the geochemical signatures and the comparison with data from previous studies, a few layers are attributed to known coeval Mt. Melbourne eruptions. Another sample subset is consistent with derivation from The Pleiades and Mt. Rittmann volcanoes. One peculiar trachytic glass population appears to be related to activity of the more distant Marie Byrd Land volcanoes. The newly detected tephras provide stratigraphic markers that could facilitate future synchronisation and dating of palaeoclimatic records. The Talos Dome tephra inventory also contributes significantly to the reconstruction of the Northern Victoria Land explosive volcanism, for which chronostratigraphic data for the Last Interglacial temporal segment are poor.
Published: 2016

53. Rooting depth, water relations and non-structural carbohydrate dynamics in three woody angiosperms differentially affected by an extreme summer drought

Author: Andrea Nardini, Valentino Casolo, Anna Dal Borgo, Paolo Bertoncin, Luca Zini, Barbara Stenni, Nate G. McDowell, and Tadeja Savi
Subjects: 0106 biological sciences, 010504 meteorology & atmospheric sciences, Soil test, Physiology, Xylem, Growing season, Plant Science, Root system, Biology, Quercus pubescens, biology.organism_classification, 01 natural sciences, Prunus, Agronomy, Hydraulic conductivity, Ostrya carpinifolia, Botany, 010606 plant biology & botany, 0105 earth and related environmental sciences
Abstract: In 2012, an extreme summer drought induced species-specific die-back in woody species in NE-Italy. Quercus pubescens and Ostrya carpinifolia were heavily impacted, while Prunus mahaleb was largely unaffected. By comparing seasonal changes in isotopic composition of xylem sap, rainfall and deep soil samples, we show that P. mahaleb has a deeper root system than the other two species. This morphological trait allowed P. mahaleb to maintain higher water potential (Ψ), gas exchange rates and non-structural carbohydrates content (NSC) throughout the summer, when compared to the other species. More favourable water and carbon states allowed relatively stable maintenance of stem hydraulic conductivity (k) throughout the growing season. In contrast, in Q. pubescens and O. carpinifolia decreasing Ψ and NSC were associated with significant hydraulic failure, with spring-to-summer k loss averaging 60%. Our data support to the hypothesis that drought-induced tree decline is a complex phenomenon that cannot be modelled on the basis of single predictors of tree status like hydraulic efficiency, vulnerability, and carbohydrate content. Our data highlight the role of rooting depth in seasonal progression of water status, gas exchange and NSC, with possible consequences for energy-demanding mechanisms involved in the maintenance of vascular integrity. This article is protected by copyright. All rights reserved.
Published: 2015

54. Author Correction: A global database of Holocene paleotemperature records

Author: Manuel Chevalier, Deborah Khider, Magaly Caniupán, Julieta Massaferro, Manuel Bringué, Marcela Sandra Tonello, Scott A. Reinemann, Ian R. Walker, Elena A. Ilyashuk, Walter Finsinger, Stephen J. Roberts, Andrew P. Rees, Mathew Fox, Pol Tarrats, Les C. Cwynar, Karen J. Taylor, Emma J. Pearson, Steve Juggins, John M. Fegyveresi, Elizabeth K. Thomas, David F. Porinchu, Anais Orsi, Nicholas P. McKay, Boris P. Ilyashuk, Oliver Heiri, Lukas Jonkers, Thomas Brussel, Vincent Montade, Eugene R. Wahl, Sakari Salonen, Darrell S. Kaufman, Martin Grosjean, Boris K. Biskaborn, Olivier Cartapanis, Tomi P. Luoto, Naomi Holmes, Cody C. Routson, Reinhard Pienitz, Brian M. Chase, Samuel L Jaccard, Louise C. Foster, Christoph Dätwyler, Angela Self, Kira Rehfeld, Aaron P. Potito, Stefan Engels, Andrei Andreev, Markus Heinrichs, Julien Emile-Geay, Nicolas Rolland, Valerie van den Bos, Jeremiah Marsicek, Mónika Tóth, Carrie Morrill, Gaute Velle, Bryan G. Mark, Andria Dawson, Mateusz Płóciennik, Konrad Gajewski, Jianyong Li, Isabelle Larocque-Tobler, Barbara Stenni, Paola Moffa-Sanchez, Liudmila Syrykh, Enlou Zhang, Shyhrete Shala, André F. Lotter, Jessica E. Tierney, Karin A. Koinig, Sebastien Bertrand, Anne de Vernal, Enikö Magyari, Petr Pařil, Matthew Peros, Snezhana Zhilich, Richard S. Vachula, M. P. Erb, Marie Claude Fortin, Krystyna M. Saunders, Elena Novenko, Larisa Nazarova, Peter G. Langdon, Yarrow Axford, Janet M. Wilmshurst, Heikki Seppä, Jeannine Marie St-Jacques, Angelica Feurdean, Philipp Sommer, Stephen J. Brooks, Anson W. Mackay, Sonja Hausmann, Steven B. Malevich, and Basil A. S. Davis
Subjects: Statistics and Probability, lcsh:Q, Physical geography, Library and Information Sciences, Statistics, Probability and Uncertainty, Author Correction, lcsh:Science, Geology, Holocene, Computer Science Applications, Education, Information Systems
Abstract: An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Published: 2020

55. Volcanic Fluxes Over the Last Millennium as Recorded in the Gv7 Ice Core (Northern Victoria Land, Antarctica)

Author: Barbara Stenni, Raffaello Nardin, Massimo Frezzotti, Mirko Severi, Alessandra Amore, Silvia Becagli, Laura Caiazzo, Rita Traversi, Nardin, R., Amore, A., Becagli, S., Caiazzo, L., Frezzotti, M., Severi, M., Stenni B., &amp, and Traversi, R.
Subjects: 010506 paleontology, 010504 meteorology & atmospheric sciences, ice cores, Volcanism, 01 natural sciences, volcanism, Antarctica, ion chromatography, paleoclimate, tephra, Ice core, Paleoclimatology, Tephra, Stratosphere, 0105 earth and related environmental sciences, geography, geography.geographical_feature_category, lcsh:QE1-996.5, lcsh:Geology, Volcano, Stratigraphy, Settore GEO/08 - Geochimica e Vulcanologia, General Earth and Planetary Sciences, Martian polar ice caps, Physical geography, ice core, Geology
Abstract: Major explosive volcanic eruptions may significantly alter the global atmosphere for about 2&ndash, 3 years. During that period, volcanic products (mainly H2SO4) with high residence time, stored in the stratosphere or, for shorter times, in the troposphere are gradually deposited onto polar ice caps. Antarctic snow may thus record acidic signals providing a history of past volcanic events. The high resolution sulphate concentration profile along a 197 m long ice core drilled at GV7 (Northern Victoria land) was obtained by Ion Chromatography on around 3500 discrete samples. The relatively high accumulation rate (241 &plusmn, 13 mm we yr &minus, 1) and the 5-cm sampling resolution allowed a preliminary counted age scale. The obtained stratigraphy covers roughly the last millennium and 24 major volcanic eruptions were identified, dated, and tentatively ascribed to a source volcano. The deposition flux of volcanic sulphate was calculated for each signature and the results were compared with data from other Antarctic ice cores at regional and continental scale. Our results show that the regional variability is of the same order of magnitude as the continental one.
Published: 2020

56. Abrupt ice-age shifts in southern westerly winds and Antarctic climate forced from the north

Author: Justin J. Wettstein, Joel B Pedro, Harald Sodemann, Barbara Stenni, Shuji Fujita, Eric J. Steig, Feng He, Motohiro Hirabayashi, Ryu Uemura, Hideaki Motoyama, Frédéric Parrenin, Kenji Kawamura, Tyler J. Fudge, Kumiko Goto-Azuma, Bradley R. Markle, Michael Sigl, Mirko Severi, Joseph R. McConnell, Christo Buizert, College of Earth, Ocean and Atmospheric Sciences [Corvallis] (CEOAS), Oregon State University (OSU), Paul Scherrer Institute (PSI), Department of Chemistry, Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Desert Research Institute (DRI), Norwegian Institute for Air Research (NILU), National Institute of Polar Research [Tokyo] (NiPR), Center for Atmospheric and Oceanic Studies [Sendai], Tohoku University [Sendai], The Graduate University for Advanced Studies, japan (SOKENDAI), University of the Ryukyus [Okinawa], Dipartimento di Scienze Geologiche [Trieste], Università degli studi di Trieste, Institut des Géosciences de l’Environnement (IGE), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Recherche pour le Développement (IRD)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and Nanchang Hangkong University
Subjects: 010506 paleontology, Multidisciplinary, 010504 meteorology & atmospheric sciences, Atmospheric circulation, Ocean current, Northern Hemisphere, Climate change, Westerlies, 01 natural sciences, 13. Climate action, Settore GEO/08 - Geochimica e Vulcanologia, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, Climatology, Ice age, 14. Life underwater, [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology, Southern Hemisphere, Geology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Teleconnection
Abstract: The mid-latitude westerly winds of the Southern Hemisphere play a central role in the global climate system via Southern Ocean upwelling, carbon exchange with the deep ocean, Agulhas leakage (transport of Indian Ocean waters into the Atlantic) and possibly Antarctic ice-sheet stability. Meridional shifts of the Southern Hemisphere westerly winds have been hypothesized to occur in parallel with the well-documented shifts of the intertropical convergence zone in response to Dansgaard-Oeschger (DO) events - abrupt North Atlantic climate change events of the last ice age. Shifting moisture pathways to West Antarctica are consistent with this view but may represent a Pacific teleconnection pattern forced from the tropics. The full response of the Southern Hemisphere atmospheric circulation to the DO cycle and its impact on Antarctic temperature remain unclear. Here we use five ice cores synchronized via volcanic markers to show that the Antarctic temperature response to the DO cycle can be understood as the superposition of two modes: a spatially homogeneous oceanic bipolar seesaw mode that lags behind Northern Hemisphere climate by about 200 years, and a spatially heterogeneous atmospheric mode that is synchronous with abrupt events in the Northern Hemisphere. Temperature anomalies of the atmospheric mode are similar to those associated with present-day Southern Annular Mode variability, rather than the Pacific-South American pattern. Moreover, deuterium-excess records suggest a zonally coherent migration of the Southern Hemisphere westerly winds over all ocean basins in phase with Northern Hemisphere climate. Our work provides a simple conceptual framework for understanding circum-Antarctic temperature variations forced by abrupt Northern Hemisphere climate change. We provide observational evidence of abrupt shifts in the Southern Hemisphere westerly winds, which have previously documented ramifications for global ocean circulation and atmospheric carbon dioxide. These coupled changes highlight the necessity of a global, rather than a purely North Atlantic, perspective on the DO cycle.
Published: 2018

57. 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

58. Assessing the robustness of Antarctic temperature reconstructions over the past two millennia using pseudoproxy and data assimilation experiments

Author: François Klein, Nerilie J. Abram, Mark A. J. Curran, Hugues Goosse, Sentia Goursaud, Valérie Masson-Delmotte, Andrew Moy, Raphael Neukom, Anaïs Orsi, Jesper Sjolte, Nathan Steiger, Barbara Stenni, and Martin Werner
Abstract: The Antarctic temperature changes over the past millennia remain more uncertain than in many other continental regions. This has several origins: 1) the number of high resolution ice cores is small, in particular on the Antarctic Plateau and in some coastal areas in East Antarctica; 2) the short instrumental records limit the calibration period for reconstructions and the assessment of the methodologies; 3) the link between isotope records from ice cores and local climate is usually complex and dependent on the spatial and time scales investigated. Here, we use climate model results, pseudoproxy and data assimilation experiments to assess the potential of reconstructing the Antarctic temperature over the last two millennia based on a new database of stable oxygen isotopes in ice cores compiled in the framework of Antarctica2k (Stenni et al., 2017). The well-known covariance between δ18O and temperature is reproduced in the two isotope-enabled models used (ECHAM5/MPI-OM and ECHAM5-wiso), but is generally weak over the different Antarctic regions, limiting the skill of the reconstructions. Furthermore, the strength of the link displays large variations over the past millennium, further affecting the potential skill of temperature reconstructions based on statistical methods which rely on the assumption that the last decades are a good estimate for longer temperature reconstructions. Using a data assimilation technique allows in theory taking into account changes in the δ18O-temperature link through time and space. Pseudoproxy experiments confirm the benefits of using data assimilation methods instead of statistical ones that provide reconstructions with unrealistic variances in some Antarctic subregions. They also confirm that the relatively weak link between both variables leads to a limited potential for reconstructing temperature based on δ18O. The reconstruction skill is however higher and more uniform among reconstruction methods when the reconstruction target is the Antarctic as a whole rather than smaller Antarctic subregions. This consistency between the methods at the large scale is also observed when reconstructing temperature based on the real δ18O regional composites of Stenni et al. (2017). In this case, temperature reconstructions based on data assimilation confirm the long term cooling over Antarctica during the last millennium, and the later onset of anthropogenic warming compared to the simulations without data assimilation, especially visible in West Antarctica. Data assimilation also allows reconciling models and direct observations by reconstructing the East-West contrast regarding the recent temperature trends, indicating that internal variability likely plays a major role in driving this heterogeneous recent warming. This is further supported by the large spread of individual PMIP/CMIP model realizations regarding the recent warming pattern. As in the pseudoproxy framework, the reconstruction methods perform differently at the subregional scale, especially in terms of the variance of the produced time series. While the potential benefits of using a data assimilation method instead of a statistical one have been highlighted in a pseudoproxy framework, the instrumental series are too short to confirm it in a realistic setup.
Published: 2018

59. Archival processes of the water stable isotope signal in East Antarctic ice cores

Author: Mathieu Casado, Amaelle Landais, Ghislain Picard, Thomas Münch, Thomas Laepple, Barbara Stenni, Giuliano Dreossi, Alexey Ekaykin, Laurent Arnaud, Christophe Genthon, Alexandra Touzeau, Valérie Masson-Delmotte, Jean Jouzel, 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 ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ), 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 national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ) -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 ), Laboratoire Chrono-environnement ( LCE ), Université Bourgogne Franche-Comté ( UBFC ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Franche-Comté ( UFC ), Department of Geological, Environmental and Marine Sciences, Universita di Trieste, University of Ca’ Foscari [Venice, Italy], Arctic and Antarctic Research Institute ( AARI ), Russian Federal Service for Hydrometeorology and Environmental Monitoring ( Roshydromet ), Laboratoire Géomatériaux ( DGCB-LGM ), École Nationale des Travaux Publics de l'État ( ENTPE ) -Centre National de la Recherche Scientifique ( CNRS ), 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), Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Department of Geological, Environmental and Marine Sciences [Trieste], Università degli studi di Trieste = University of Trieste, Arctic and Antarctic Research Institute (AARI), Russian Federal Service for Hydrometeorology and Environmental Monitoring (Roshydromet), 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), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Recherche pour le Développement (IRD)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Università degli studi di Trieste, 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), Laboratoire de glaciologie et géophysique de l'environnement (LGGE), 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), Laboratoire Chrono-environnement - UFC (UMR 6249) (LCE), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Laboratoire Géomatériaux (DGCB-LGM), and École Nationale des Travaux Publics de l'État (ENTPE)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, [ SDU.OCEAN ] Sciences of the Universe [physics]/Ocean, Atmosphere, 010504 meteorology & atmospheric sciences, 010502 geochemistry & geophysics, 01 natural sciences, 13. Climate action, Settore GEO/08 - Geochimica e Vulcanologia, ddc:550, [ SDU.ENVI ] Sciences of the Universe [physics]/Continental interfaces, environment, Institut für Geowissenschaften, Mathematisch-Naturwissenschaftliche Fakultät, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, human activities, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, ddc:910
Abstract: International audience; The oldest ice core records are obtained from the East Antarctic Plateau. Water isotopes are key proxies to reconstructing past climatic conditions over the ice sheet and at the evaporation source. The accuracy of climate reconstructions depends on knowledge of all processes affecting water vapour, precipitation and snow isotopic compositions. Fractionation processes are well understood and can be integrated in trajectory-based Rayleigh distillation and isotope-enabled climate models. However, a quantitative understanding of processes potentially altering snow isotopic composition after deposition is still missing. In low-accumulation sites, such as those found in East Antarctica, these poorly constrained processes are likely to play a significant role and limit the interpretability of an ice core's isotopic composition. By combining observations of isotopic composition in vapour, precipitation, surface snow and buried snow from Dome C, a deep ice core site on the East Antarctic Plateau, we found indications of a seasonal impact of metamorphism on the surface snow isotopic signal when compared to the initial precipitation. Particularly in summer, exchanges of water molecules between vapour and snow are driven by the diurnal sublimation-condensation cycles. Overall, we observe in between precipitation events modification of the surface snow isotopic composition. Using high-resolution water isotopic composition profiles from snow pits at five Antarctic sites with different accumulation rates, we identified common patterns which cannot be attributed to the seasonal variability of precipitation. These differences in the precipitation, surface snow and buried snow isotopic composition provide evidence of post-deposition processes affecting ice core records in low-accumulation areas.
Published: 2018

60. Alpine High Monitoring Station in Belluno Dolomites of Italian Eastern Alps

Author: Massimiliano Vardè (1, Federico Dallo (1), Jacopo Gabrieli (1), Warren Cairns (1), Giulio Cozzi (1), Paolo Cristofanelli (3), Francescopiero Calzolari (3), Paolo Bonasoni (3), Giuliano Dreossi (1, Barbara Stenni (4), and Carlo Barbante (1
Subjects: Dolomites, High Monitoring Station, Italian Eastern Alps, Alpine
Abstract: The high-altitude mountain monitoring station of the Institute for the Dynamics of Environmental Processes (IDPA) of the Italian National Research Council (CNR) is located in the Italian Eastern Alps at Col Margherita in the Dolomites above Belluno (2550 m a.s.l.). Set up in 2011 as part of the GMOS project (2010-2015) the Col Margherita site (MRG) was part of a network of 40 remote stations globally distributed between the northern and southern hemisphere for the study of atmospheric mercury. In 2017 an ozone monitor was installed and the equipment upgraded thanks to funds from the Italian National Project (NextDATA, 2012-2018) and improved collaboration with other research groups. Additional field and laboratory equipment for the study of atmospheric pollutants in line with the objectives of the ERA-Planet iGOSP project (2017-2020) will be acquired. This project aims to improve and strengthen the networks observing mercury and persistent organic pollutants. Measurements of mercury and ozone in the atmosphere, mercury and other metals, POPs, ?18O and ?D in precipitation will be carried out regularly in the framework of the project. These activities will be used to develop QA/QC protocols to improve the intercomparability/reproducibility of environmental data. The MRG observatory is equipped with an automatic weather station (AWS) for the main meteorological parameters (T, Pa, RH, WS, WD, rainfall depth) and its high-altitude location, allows the study of the long-range transport of numerous air pollutants and their deposition in precipitation. This is because, for many months of the year, especially in winter, the atmospheric boundary layer is below the altitude of the station. The site is available and ready to participate in projects, such as high-altitude climate monitoring, for the study of species that have an impact on climate change (CO2, CH4, BC). We are also ready to host instrumentation from other research institutions.
Published: 2018

61. Water Masses in the Eastern Mediterranean Sea: An Analysis of Measured Isotopic Oxygen

Author: Davide Zanchettin, Barbara Stenni, Paola de Ruggiero, Stefano Pierini, Angelo Rubino, Manuel Bensi, and Dagmar Hainbucher
Subjects: Water mass, Adriatic Sea, 010504 meteorology & atmospheric sciences, 010505 oceanography, δ18O, Settore GEO/12 - Oceanografia e Fisica dell'Atmosfera, Ionian Sea, Isotopic oxygen, 01 natural sciences, interdecadal variability, Salinity, Eastern mediterranean, Oceanography, Mediterranean sea, Water column, Geophysics, Geochemistry and Petrology, Statistical analyses, Environmental science, water mass identification, 0105 earth and related environmental sciences
Abstract: We investigate aspects of the water mass structure of the Adriatic and Ionian basins (Eastern Mediterranean Sea) and their interdecadal variability through statistical analyses focused on δ18O measurements carried out in 1985, 1990, and 2011. In particular, the more recent δ18O measurements extend throughout the entire water column and constitute, to the best of our knowledge, the largest synoptic dataset encompassing different sub-basins of the Mediterranean Sea. We study the statistical linkages between temperature, salinity, dissolved oxygen and δ18O. We find that δ18O is largely independent from the other parameters, and it can be used to trace major water masses that are typically found in the basins, including the Adriatic Dense Water, the Levantine Intermediate Water, and the Cretan Intermediate and Dense Waters. Finally, we explore the possibility of using δ18O concentration as a proxy for dominant modes of large-scale oceanic variability in the Mediterranean Sea.
Published: 2018

62. The atmospheric water cycle of a coastal lagoon: an isotope study of the interactions between water vapor, precipitation and surface waters

Author: Barbara Stenni, Daniele Zannoni, Giancarlo Rampazzo, Hans Christian Steen-Larsen, Giuliano Dreossi, and Andrea Bergamasco
Subjects: Evapotranspiration, Lagoon, Precipitation, Stable isotopes, Surface water, Water vapor, 010504 meteorology & atmospheric sciences, Settore GEO/12 - Oceanografia e Fisica dell'Atmosfera, 0207 environmental engineering, 02 engineering and technology, Atmospheric sciences, 01 natural sciences, Isotopic signature, Water cycle, 020701 environmental engineering, 0105 earth and related environmental sciences, Water Science and Technology, Moisture, Humidity, Settore GEO/08 - Geochimica e Vulcanologia, Environmental science
Abstract: The interaction between the different components of the water cycle at ecosystem scale is of great interest in hydroecology. Stable isotopes of hydrogen and oxygen in the water molecule can be used to study these processes quantitatively due to their different physical properties. This study aims at quantifying the contribution of local moisture sources to the isotopic signature of water vapor in the specific estuary system of a coastal lagoon. Here we present a framework of the isotopic composition of the atmospheric water cycle components (water vapor and precipitation) for the coastal lagoon of Venice (Italy) and we discuss the interaction between the atmospheric component and the surface component of the local water cycle, i.e. the atmospheric moisture and the lagoon water. The Venetian Lagoon is an enclosed basin with low freshwater influx, resulting in the presence of large horizontal gradients of the isotopic composition of surface water. This feature allows to determine the sensitivity of the isotopic signal in near surface atmospheric moisture under a range of humidity conditions. We observed that when the lower atmosphere is close to water vapor saturation pressure condition, the isotopic composition of water vapor at the ground appears to be in isotopic equilibrium with lagoon surface water in a range of approximately 6–26 km from the sampling point. On the other hand, under unsaturated conditions, we estimated that lagoon evaporation flux accounts on average for ∼27% to the daily (06–18 Local Sidereal Time) total evapotranspiration surface flux. This is the first study that discusses the spatio-temporal variability of water vapor, precipitation and surface water isotopic composition for a coastal lagoon, thus including the major components of the local water cycle in an estuarine system with the isotope approach.
Published: 2018
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63. Vineyard water relations in a karstic area: deep roots and irrigation management

Author: Andrea Nardini, Francesco Petruzzellis, Stefano Martellos, Klemen Lisjak, Tadeja Savi, Luca Zini, Barbara Stenni, Anna Dal Borgo, Savi, Tadeja, Petruzzellis, Francesco, Martellos, Stefano, Stenni, Barbara, Dal Borgo, Anna, Zini, Luca, Lisjak, Klemen, and Nardini, Andrea
Subjects: 0106 biological sciences, Irrigation, Drought stress, Deficit irrigation, Water statu, Vitis vinifera cv. Malvasia Istriana, 01 natural sciences, Vineyard, Limestone soils, VITIS-VINIFERA, Water status, Drought stress, Oxygen isotopes, Vitis vinifera cv. Malvasia Istriana, Limestone soils REGULATED DEFICIT IRRIGATION, VITIS-VINIFERA, STRUCTURAL RESPONSES, ADAPTIVE STRATEGIES, STOMATAL BEHAVIOR, CLIMATE-CHANGE, GRAPEVINE, DROUGHT, FIELD, GROWTH, GRAPEVINE, FIELD, Irrigation management, Limestone soils REGULATED DEFICIT IRRIGATION, DROUGHT, Transpiration, Topsoil, CLIMATE-CHANGE, ADAPTIVE STRATEGIES, Ecology, fungi, Oxygen isotopes, Water status, Animal Science and Zoology, Agronomy and Crop Science, food and beverages, 04 agricultural and veterinary sciences, STRUCTURAL RESPONSES, Oxygen isotope, Water resources, Agronomy, Settore GEO/08 - Geochimica e Vulcanologia, STOMATAL BEHAVIOR, Soil water, 040103 agronomy & agriculture, GROWTH, 0401 agriculture, forestry, and fisheries, Environmental science, Drought stre, Limestone soil, 010606 plant biology & botany
Abstract: Ongoing variations in rainfall and temperature regimes affect the physiology and productivity of grapevines, calling for irrigation in drought-prone areas. During vintage 2015, we monitored plants water status and indirectly assessed rooting depth and exploited water sources (oxygen isotope analyses) in a mature Vitis vinifera cv. Malvasia Istriana vineyard on red soils ("terra rossa") developed on highly permeable carbonate rocks. We also investigated effects of topsoil irrigation or late summer rains on plant water status and yield. Under the harsh summer environmental conditions of 2015, the plant water status was overall favorable (moderate water deficit) and never reached critical levels, suggesting that irrigation was not mandatory. Leaf conductance to water vapor (g(L)) measured in July decreased by about 70% compared to spring, while minimum leaf water potential (Psi(min)) dropped by only 16%, suggesting an isohydric behavior of the cultivar (strict stomatal control of transpiration). Both Psi(min) and g(L) reached a minimum in July (peak of drought), and returned to pre-drought values in late summer. Rainfalls or supplemental irrigation (about 40 mm) promoted prompt recovery of plant water status. Irrigation treatments or occasional summer rainfalls can influence the water status of plants, although roots have access to deep water sources. In fact, the isotopic composition of xylem sap was similar to that of soil water sampled in a nearby deep cave, supporting the hypothesis that deep soil is the main water source for grapevines in karstic areas during summertime. Deficit irrigation, based on careful evaluation of physiological indicators of plant water status, might be an effective strategy for promoting sustainable viticulture, and a rationale use of water resources in karstic ecosystems.
Published: 2018

64. The global distribution of natural tritium in precipitation simulated with an Atmospheric General Circulation Model and comparison with observations

Author: Amaelle Landais, Camille Risi, Philippe Jean-Baptiste, Barbara Stenni, Elise Fourré, Alexandre Cauquoin, 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), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Dipartimento di Geoscienze, 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), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), and Università degli studi di Trieste = University of Trieste
Subjects: ITASE TRAVERSE, FOS: Physical sciences, Atmospheric sciences, 7. Clean energy, CUMULUS CONVECTION, Troposphere, REANALYSIS, ISOTOPIC SNOW VARIABILITY, stratospheric air intrusions STRATOSPHERE-TROPOSPHERE EXCHANGE, Geochemistry and Petrology, Earth and Planetary Sciences (miscellaneous), WATER, Precipitation, Water cycle, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Stratosphere, ComputingMilieux_MISCELLANEOUS, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, EAST ANTARCTICA, Isotope, tritium, Stable isotope ratio, hydrological cycle, GCM, tritium, hydrological cycle, GCM, stratospheric air intrusions STRATOSPHERE-TROPOSPHERE EXCHANGE, ISOTOPIC SNOW VARIABILITY, CUMULUS CONVECTION, EAST ANTARCTICA, ITASE TRAVERSE, WATER, CLIMATE, REANALYSIS, TRANSPORT, FALLOUT, TRANSPORT, FALLOUT, CLIMATE, Physics - Atmospheric and Oceanic Physics, Geophysics, Settore GEO/08 - Geochimica e Vulcanologia, 13. Climate action, Space and Planetary Science, General Circulation Model, Climatology, Atmospheric and Oceanic Physics (physics.ao-ph), Tritium, Geology
Abstract: The description of the hydrological cycle in Atmospheric General Circulation Models (GCMs) can be validated using water isotopes as tracers. Many GCMs now simulate the movement of the stable isotopes of water, but here we present the first GCM simulations modelling the content of natural tritium in water. These simulations were obtained using a version of the LMDZ General Circulation Model enhanced by water isotopes diagnostics, LMDZ-iso. To avoid tritium generated by nuclear bomb testing, the simulations have been evaluated against a compilation of published tritium datasets dating from before 1950, or measured recently. LMDZ-iso correctly captures the observed tritium enrichment in precipitation as oceanic air moves inland (the so-called continental effect) and the observed north-south variations due to the latitudinal dependency of the cosmogenic tritium production rate. The seasonal variability, linked to the stratospheric intrusions of air masses with higher tritium content into the troposphere, is correctly reproduced for Antarctica with a maximum in winter. LMDZ-iso reproduces the spring maximum of tritium over Europe, but underestimates it and produces a peak in winter that is not apparent in the data. This implementation of tritium in a GCM promises to provide a better constraint on: (1) the intrusions and transport of air masses from the stratosphere and (2) the dynamics of the modelled water cycle. The method complements the existing approach of using stable water isotopes., Accepted paper version. See published version in EPSL Elsevier website
Published: 2015

65. Supplementary material to 'Archival processes of the water stable isotope signal in East Antarctic ice cores'

Author: Mathieu Casado, Amaelle Landais, Ghislain Picard, Thomas Münch, Thomas Laepple, Barbara Stenni, Giuliano Dreossi, Alexey Ekaykin, Laurent Arnaud, Christophe Genthon, Alexandra Touzeau, Valérie Masson-Delmotte, and Jean Jouzel
Published: 2017

66. Review of regional Antarctic snow accumulation over the past 1000 years

Author: Jason L. Roberts, Brooke Medley, Massimo Frezzotti, Alexey A. Ekaykin, Elisabeth Isaksson, Tyler J. Fudge, Jan T. M. Lenaerts, Michiel R. van den Broeke, Mark A. J. Curran, Elizabeth R. Thomas, Paul Vallelonga, Elisabeth Schlosser, Barbara Stenni, Nancy A. N. Bertler, J. Melchior van Wessem, and Daniel A. Dixon
Subjects: 0301 basic medicine, geography, geography.geographical_feature_category, Plateau, 010504 meteorology & atmospheric sciences, Antarctic ice sheet, Snow, 01 natural sciences, 03 medical and health sciences, Glacier mass balance, 030104 developmental biology, Ice core, 13. Climate action, Peninsula, Climatology, Cryosphere, Environmental science, Precipitation, 0105 earth and related environmental sciences
Abstract: Here we review Antarctic snow accumulation variability, at the regional scale, over the past 1000 years. A total of 80 ice core snow accumulation records were gathered, as part of a community led project coordinated by the PAGES Antarctica 2k working group. The ice cores were assigned to seven geographical regions, separating the high accumulation coastal zones below 2000 m elevation from the dry central Antarctic Plateau. The regional composites of annual snow accumulation were evaluated against modelled surface mass balance (SMB) from RACMO2.4 and precipitation from ERA-interim reanalysis. With the exception of the Weddell Sea coast, the low-elevation composites capture the regional precipitation and SMB variability. The central Antarctic sites lack coherency and are either not representing regional precipitation or indicate the models inability to capture relevant precipitation processes in the cold, dry central plateau. The drivers of precipitation are reviewed for each region and the temporal variability and trends evaluated over the past 100, 200 and 1000 years. Our study suggests an overall increase in SMB across the grounded Antarctic ice sheet of ~ 44 GT since 1800 AD, with the largest (area-weighted) contribution from the Antarctic Peninsula (AP). Only four ice core records cover the full 1000 years and suggest a decrease in snow accumulation during this period. However, our study emphasizes the importance of low elevation coastal zones (especially AP and DML), which have been underrepresented in previous investigations of temporal snow accumulation.
Published: 2017

67. Antarctic climate variability at regional and continental scales over the last 2,000 years

Author: Hugues Goosse, Raphael Neukom, Sentia Goursaud, Nancy A. N. Bertler, Martin Werner, Barbara Stenni, Mark A. J. Curran, Anais Orsi, D. Divine, Tas van Ommen, Elisabeth Isaksson, Daniel A. Dixon, Nerilie J. Abram, Massimo Frezzotti, Alexey A. Ekaykin, Eric J. Steig, Valérie Masson-Delmotte, and Elisabeth R. Thomas
Subjects: 0301 basic medicine, geography, geography.geographical_feature_category, 010504 meteorology & atmospheric sciences, European Project for Ice Coring in Antarctica, Antarctic ice sheet, Context (language use), Future sea level, 01 natural sciences, Ice-sheet model, 03 medical and health sciences, 030104 developmental biology, Ice cap climate, Ice core, 13. Climate action, Peninsula, Climatology, Geology, 0105 earth and related environmental sciences
Abstract: Climate trends in the Antarctic region remain poorly characterised, owing to the brevity and scarcity of direct climate observations and the large magnitude of interannual to decadal-scale climate variability. Here, within the framework of the PAGES Antarctica 2k working group, we build an enlarged database of ice core water stable isotope records from Antarctica, consisting of 112 records. We produce both unweighted and weighted isotopic (δ18O) composites and temperature reconstructions since 0 CE, binned at 5 and 10-year resolution, for 7 climatically-distinct regions covering the Antarctic continent. Following earlier work of the Antarctica 2k working group, we also produce composites and reconstructions for the broader regions of East Antarctica, West Antarctica, and the whole continent. We use three methods for our temperature reconstructions: i) a temperature scaling based on the δ18O-temperature relationship output from an ECHAM5-wiso model simulation nudged to ERA-interim atmospheric reanalyses from 1979 to 2013, and adjusted for the West Antarctic Ice Sheet region to borehole temperature data; ii) a temperature scaling of the isotopic normalized anomalies to the variance of the regional reanalysis temperature and iii) a composite-plus-scaling approach used in a previous continental scale reconstruction of Antarctic temperature since 1 CE but applied to the new Antarctic ice core database. Our new reconstructions confirm a significant cooling trend from 0 to 1900 CE across all Antarctic regions where records extend back into the 1st millennium, with the exception of the Wilkes Land coast and Weddell Sea coast regions. Within this long-term cooling trend from 0–1900 CE we find that the warmest period occurs between 300 and 1000 CE, and the coldest interval from 1200 to 1900 CE. Since 1900 CE, significant warming trends are identified for the West Antarctic Ice Sheet, the Dronning Maud Land coast and the Antarctic Peninsula regions, and these trends are robust across the distribution of records that contribute to the unweighted isotopic composites and also significant in the weighted temperature reconstructions. Only for the Antarctic Peninsula is this most recent century-scale trend unusual in the context of natural variability over the last 2000-years. However, projected warming of the Antarctic continent during the 21st Century may soon see significant and unusual warming develop across other parts of the Antarctic continent. The extended Antarctica 2k ice core isotope database developed by this working group opens up many avenues for developing a deeper understanding of the response of Antarctic climate to natural and anthropogenic climate forcings. The first long-term quantification of regional climate in Antarctica presented herein is a basis for data-model comparison and assessments of past, present and future driving factors of Antarctic climate.
Published: 2017

68. Supplementary material to 'Antarctic climate variability at regional and continental scales over the last 2,000 years'

Author: Barbara Stenni, Mark A. J. Curran, Nerilie J. Abram, Anais Orsi, Sentia Goursaud, Valerie Masson-Delmotte, Raphael Neukom, Hugues Goosse, Dmitry Divine, Tas van Ommen, Eric J. Steig, Daniel A. Dixon, Elisabeth R. Thomas, Nancy A. N. Bertler, Elisabeth Isaksson, Alexey Ekaykin, Massimo Frezzotti, and Martin Werner
Published: 2017

69. Experimental observation of transient δ18O interaction between snow and advective airflow under various temperature gradient conditions

Author: Pirmin P. Ebner, Hans Christian Steen-Larsen, Barbara Stenni, Martin Schneebeli, and Aldo Steinfeld
Abstract: Stable water isotopes (δ18O) obtained from snow and ice samples of polar regions are used to reconstruct past climate variability, but heat and mass transport processes can affect the isotopic composition. Here we present an experimental study on the effect on the snow isotopic composition by airflow through a snow pack in controlled laboratory conditions. The influence of isothermal and controlled temperature gradient conditions on the δ18O content in the snow and interstitial water vapor is elucidated. The observed disequilibrium between snow and vapor isotopes led to exchange of isotopes between snow and vapor under non-equilibrium processes, significantly changing the δ18O content of the snow. The type of metamorphism of the snow had a significant influence on this process. These findings are pertinent to the interpretation of the records of stable isotopes of water from ice cores. These laboratory measurements suggest that a highly resolved history is relevant for the interpretation of the snow isotopic composition in the field.
Published: 2017

70. The influence of the synoptic regime on stable water isotopes in precipitation at Dome C, East Antarctica

Author: Elisabeth Schlosser, Anna Dittmann, Barbara Stenni, Jordan G. Powers, Kevin W. Manning, Valérie Masson-Delmotte, Mauro Valt, Anselmo Cagnati, Paolo Grigioni, Claudio Scarchilli, Department of Atmospheric and Cryospheric Sciences [Innsbruck] (ACINN), Universität Innsbruck [Innsbruck], University of Ca’ Foscari [Venice, Italy], National Center for Atmospheric Research [Boulder] (NCAR), 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), ARPA Center of Avalanches, Arabba, ENEA Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Via Anguillarese, 301, 00123 S. Maria di Galeria, Rome, Italy, 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: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, DRONNING MAUD LAND, WEST ANTARCTICA, FORECASTING WRF MODEL, SURFACE SNOW, ICE CORES, DRONNING MAUD LAND, MESOSCALE-PREDICTION-SYSTEM, POLAR WEATHER RESEARCH, FORECASTING WRF MODEL, SURFACE SNOW, WEST ANTARCTICA, ICE CORES, ATMOSPHERIC CIRCULATION, DEUTERIUM EXCESS, ACCUMULATION, 13. Climate action, Settore GEO/08 - Geochimica e Vulcanologia, POLAR WEATHER RESEARCH, DEUTERIUM EXCESS, MESOSCALE-PREDICTION-SYSTEM, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, ATMOSPHERIC CIRCULATION, ComputingMilieux_MISCELLANEOUS, ACCUMULATION
Abstract: The correct derivation of paleotemperatures from ice cores requires exact knowledge of all processes involved before and after the deposition of snow and the subsequent formation of ice. At the Antarctic deep ice core drilling site Dome C, a unique data set of daily precipitation amount, type, and stable water isotope ratios is available that enables us to study in detail atmospheric processes that influence the stable water isotope ratio of precipitation. Meteorological data from both automatic weather station and a mesoscale atmospheric model were used to investigate how different atmospheric flow patterns determine the precipitation parameters. A classification of synoptic situations that cause precipitation at Dome C was established and, together with back-trajectory calculations, was utilized to estimate moisture source areas. With the resulting source area conditions (wind speed, sea surface temperature, and relative humidity) as input, the precipitation stable isotopic composition was modeled using the so-called Mixed Cloud Isotope Model (MCIM). The model generally underestimates the depletion of 18O in precipitation, which was not improved by using condensation temperature rather than inversion temperature. Contrary to the assumption widely used in ice core studies, a more northern moisture source does not necessarily mean stronger isotopic fractionation. This is due to the fact that snowfall events at Dome C are often associated with warm air advection due to amplification of planetary waves, which considerably increases the site temperature and thus reduces the temperature difference between source area and deposition site. In addition, no correlation was found between relative humidity at the moisture source and the deuterium excess in precipitation. The significant difference in the isotopic signal of hoarfrost and diamond dust was shown to disappear after removal of seasonality. This study confirms the results of an earlier study carried out at Dome Fuji with a shorter data set using the same methods.
Published: 2017

71. Prominent features in isotopic, chemical and dust stratigraphies from coastal East Antarctic ice sheet (Eastern Wilkes Land)

Author: Claudio Scarchilli, Virginia Ciardini, Heejin Hwang, Barbara Stenni, Jacopo Gabrieli, Rita Traversi, Silvia Becagli, Biancamaria Narcisi, Roberto Udisti, I. Crotti, Massimo Frezzotti, Giuliano Dreossi, Mirko Severi, E. Selmo, Sang-Bum Hong, Laura Caiazzo, Yeongcheol Han, Giovanni Baccolo, Jung-Ho Kang, Andrea Spolaor, Soon Do Hur, Barbara Delmonte, Marco Proposito, Fabio Giardi, Carlo Barbante, Michele Bertò, Caiazzo, L., Baccolo, G., Barbante, C., Becagli, S., Berto, M., Ciardini, V., Crotti, I., Delmonte, B., Dreossi, G., Frezzotti, M., Gabrieli, J., Giardi, F., Han, Y., Hong, S. -B., Hur, S. D., Hwang, H., Kang, J. -H., Narcisi, B., Proposito, M., Scarchilli, C., Selmo, E., Severi, M., Spolaor, A., Stenni, B., Traversi, R., Udisti, R., Caiazzo, L, Baccolo, G, Barbante, C, Becagli, S, Bertò, M, Ciardini, V, Crotti, I, Delmonte, B, Dreossi, G, Frezzotti, M, Gabrieli, J, Giardi, F, Han, Y, Hong, S, Hur, S, Hwang, H, Kang, J, Narcisi, B, Proposito, M, Scarchilli, C, Selmo, E, Severi, M, Spolaor, A, Stenni, B, Traversi, R, and Udisti, R
Subjects: Snow pit, Environmental Engineering, 010504 meteorology & atmospheric sciences, Chemical composition, Dating, East Antarctica, GV7, Seasonal pattern, Chemistry (all), Environmental Chemistry, Health, Toxicology and Mutagenesis, GEO/04 - GEOGRAFIA FISICA E GEOMORFOLOGIA, Antarctic ice sheet, Antarctic Regions, Mineral dust, Oxygen Isotopes, 010502 geochemistry & geophysics, 01 natural sciences, Isotopes of oxygen, Snow, Ice Cover, Oxygen Isotope, Precipitation, Aerosol, 0105 earth and related environmental sciences, Aerosols, Antarctic Region, Pacific Ocean, Sulfur Compounds, Firn, Public Health, Environmental and Occupational Health, Australia, Dust, General Medicine, General Chemistry, Sea spray, Pollution, Oceanography, Settore GEO/08 - Geochimica e Vulcanologia, Environmental science, Physical geography, Seasons, Season, Environmental Monitoring
Abstract: In this work we present the isotopic, chemical and dust stratigraphies of two snow pits sampled in 2013/14at GV7 (coastal East Antarctica: 70°41′ S - 158°51′ E, 1950 m a.s.l.). A large number of chemical species are measured aiming to study their potentiality as environmental changes markers. Seasonal cluster backward trajectories analysis was performed and compared with chemical marker stratigraphies. Sea spray aerosol is delivered to the sampling site together with snow precipitation especially in autumn-winter by air masses arising from Western Pacific Ocean sector. Dust show maximum concentration in spring when the air masses arising from Ross Sea sector mobilize mineral dust from ice-free areas of the Transantarctic mountains. The clear seasonal pattern of sulfur oxidized compounds allows the dating of the snow-pit and the calculation of the mean accumulation rate, which is 242±71mm w.e. for the period 2008–2013. Methanesulfonic acid and NO3− do not show any concentration decreasing trend as depth increases, also considering a 12m firn core record. Therefore these two compounds are not affected by post-depositional processes at this site and can be considered reliable markers for past environmental changes reconstruction. The rBC snow-pit record shows the highest values in summer 2012 likely related to large biomass burning even occurred in Australia in this summer. The undisturbed accumulation rate for this site is demonstrated by the agreement between the chemical stratigraphies and the annual accumulation rate of the two snow-pits analysed in Italian and Korean laboratories.
Published: 2017

72. Sea salt sodium record from Talos Dome (East Antarctica) as a potential proxy of the Antarctic past sea ice extent

Author: Ester Colizza, Silvia Becagli, Mirko Severi, Claudio Scarchilli, Virginia Ciardini, Fabio Giardi, Roberto Udisti, Karin Mezgec, Barbara Stenni, Laura Caiazzo, Elizabeth R. Thomas, Rita Traversi, Scarchilli, C., Severi, M, Becagli, S., Caiazzo, L., Ciardini, V., Colizza, Ester, Giardi, F., Mezgec, K., Stenni, B., Thomas, E. R., Traversi, R., and Udisti, R.
Subjects: Arctic sea ice decline, Environmental Engineering, 010504 meteorology & atmospheric sciences, Health, Toxicology and Mutagenesis, Climate, Antarctic Regions, Antarctic sea ice, Antarctica, Climate change, Ice-core, Paleo reconstruction, Ross Sea, Sea-ice, Chemistry (all), Environmental Chemistry, 010502 geochemistry & geophysics, 01 natural sciences, Meteorology, Ice core, Sea ice, Cryosphere, Seawater, Ice Cover, 14. Life underwater, 0105 earth and related environmental sciences, Antarctic Region, Drift ice, geography, geography.geographical_feature_category, Pacific Ocean, Sodium, Public Health, Environmental and Occupational Health, General Medicine, General Chemistry, Linear Models, Pollution, Arctic ice pack, Oceanography, 13. Climate action, Settore GEO/08 - Geochimica e Vulcanologia, Linear Model, Ice sheet, Geology
Abstract: Antarctic sea ice has shown an increasing trend in recent decades, but with strong regional differences from one sector to another of the Southern Ocean. The Ross Sea and the Indian sectors have seen an increase in sea ice during the satellite era (1979 onwards). Here we present a record of ssNa+ flux in the Talos Dome region during a 25-year period spanning from 1979 to 2003, showing that this marker could be used as a potential proxy for reconstructing the sea ice extent in the Ross Sea and Western Pacific Ocean at least for recent decades. After finding a positive relationship between the maxima in sea ice extent for a 25-year period, we used this relationship in the TALDICE record in order to reconstruct the sea ice conditions over the 20th century. Our tentative reconstruction highlighted a decline in the sea ice extent (SIE) starting in the 1950s and pointed out a higher variability of SIE starting from the 1960s and that the largest sea ice extents of the last century occurred during the 1990s. © 2017 Elsevier Ltd
Published: 2017

73. Holocene sea ice variability driven by wind and polynya efficiency in the Ross Sea

Author: Maria Cristina Salvatore, Virginia Ciardini, Carlo Baroni, Claudio Scarchilli, Valérie Masson-Delmotte, Xavier Crosta, Rita Traversi, Barbara Stenni, Karin Mezgec, Martina Braida, Massimo Frezzotti, Roberto Udisti, Ester Colizza, Mirko Severi, Romana Melis, Università degli Studi di Siena = University of Siena (UNISI), Dipartimento di Scienze Geologiche [Trieste], Università degli studi di Trieste = University of Trieste, Environnements et Paléoenvironnements OCéaniques (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), 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), Istituto di Geoscienze e Georisorse, University of Pisa - Università di Pisa, Agenzia Nazionale per le nuove Tecnologie, l’energia e lo sviluppo economico sostenibile = Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Università degli Studi di Firenze = University of Florence (UniFI), Italian National agency for new technologies, Energy and sustainable economic development [Frascati] (ENEA), Università degli studi di Trieste, Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE), 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), University of Trieste, Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Ciardini, V., Scarchilli, C., Mezgec, K., Stenni, B., Crosta, X., Masson-Delmotte, V., Baroni, C., Braida, M., Colizza, E., Melis, Roberta, Salvatore, M. C., Severi, M., Traversi, R., Udisti, R., Frezzotti, M., Baroni, Carlo, Melis, R., Scarchilli, Claudio, and Frezzotti, Monica
Subjects: Arctic sea ice decline, Genetics and Molecular Biology (all), 010504 meteorology & atmospheric sciences, Science, Sea ice, General Physics and Astronomy, Antarctic sea ice, 010502 geochemistry & geophysics, palaeoclimate, 01 natural sciences, Biochemistry, Article, General Biochemistry, Genetics and Molecular Biology, Physics and Astronomy (all), Ice core, parasitic diseases, katabatic wind, 14. Life underwater, [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology, lcsh:Science, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, 0105 earth and related environmental sciences, Drift ice, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, geography, polynyas, Multidisciplinary, geography.geographical_feature_category, Biochemistry, Genetics and Molecular Biology (all), Holocene, Chemistry (all), General Chemistry, Arctic ice pack, marine and continental proxies data, Ross sea, Oceanography, Settore GEO/08 - Geochimica e Vulcanologia, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, Interglacial, Sea ice thickness, Antarctica, lcsh:Q, Sea ice, polynyas, marine and continental proxies data, katabatic wind, palaeoclimate, Holocene, Ross sea, Antarctica, human activities, Geology
Abstract: The causes of the recent increase in Antarctic sea ice extent, characterised by large regional contrasts and decadal variations, remain unclear. In the Ross Sea, where such a sea ice increase is reported, 50% of the sea ice is produced within wind-sustained latent-heat polynyas. Combining information from marine diatom records and sea salt sodium and water isotope ice core records, we here document contrasting patterns in sea ice variations between coastal and open sea areas in Western Ross Sea over the current interglacial period. Since about 3600 years before present, an increase in the efficiency of regional latent-heat polynyas resulted in more coastal sea ice, while sea ice extent decreased overall. These past changes coincide with remarkable optima or minima in the abundances of penguins, silverfish and seal remains, confirming the high sensitivity of marine ecosystems to environmental and especially coastal sea ice conditions., Strong regional heterogeneity prevents thorough understanding of the recent increase in Antarctic sea ice. Here, analysis of marine and ice cores in the Western Ross Sea shows that late Holocene contrasting sea ice patterns between open and coastal areas are related to katabatic winds and polynya efficiency.
Published: 2017

74. Isotopic features of precipitation and groundwater from the Eastern Alps of Italy: results from the Mt. Tinisa hydrogeological system

Author: Federico Cervi, Lisa Borgatti, Barbara Stenni, Giuliano Dreossi, Marzia Michelini, Gianluca Marcato, Cervi, F., Borgatti, Lisa, Dreossi, G., Marcato, G., Michelini, M., and Stenni, B.
Subjects: Rainfall, 010504 meteorology & atmospheric sciences, Eastern Alps, 0208 environmental biotechnology, Soil Science, Aquifer, 02 engineering and technology, 01 natural sciences, Rainwater harvesting, Eastern Alp, Environmental Chemistry, Precipitation, Mean residence time, Groundwater, 0105 earth and related environmental sciences, Water Science and Technology, Earth-Surface Processes, Hydrology, geography, Global and Planetary Change, Hydrogeology, geography.geographical_feature_category, Italy, Water isotopes, Pollution, Geology, Groundwater recharge, Water isotope, 020801 environmental engineering, Settore GEO/08 - Geochimica e Vulcanologia, Meteoric water, Surface runoff
Abstract: This study analyses water stable isotopes data collected from precipitation (one rain gauge) and groundwater outlets (seven occurrences and two springs) at Mt. Tinisa, in the Eastern Alps of Italy. Limestones and dolostones outcrop in the mountain relief, making up a single aquifer which feeds the monitored outlets with almost steady discharges. Lack of runoff in the streambeds throughout the whole year means that all meteoric water can be considered as recharging the aquifer. Sampling was undertaken during the periods 2005â2010 (precipitation) and 2014â2015 (groundwater) via monthly and two/three-monthly field-activities, respectively, which allowed a total of 138 water samples to be gathered and analysed. Results highlighted the presence of apparent isotopic anomalies in groundwater in comparison with meteoric water. The study demonstrates that the assessment of groundwater residence time and estimates of the mean monthly isotopic content in rainwater have been necessary to correctly compare the two isotopic datasets and relate the anomaly to the recharge time-window, occurring in the late autumn.
Published: 2017

75. Larix decidua δ18O tree-ring cellulose mainly reflects the isotopic signature of winter snow in a high-altitude glacial valley of the European Alps

Author: Giovanni Leonelli, Maurizio Maugeri, Giovanna Battipaglia, Matthias Saurer, Barbara Stenni, Rolf T. W. Siegwolf, Valter Maggi, Manuela Pelfini, Paolo Cherubini, Stella Fusco, Leonelli, G, Battipaglia, G, Cherubini, P, Saurer, M, Siegwolf, R, Maugeri, M, Stenni, B, Fusco, S, Maggi, V, Pelfini, M, Università degli Studi di Milano-Bicocca [Milano] (UNIMIB), Seconda Università degli studi di Napoli, Institut des Sciences de l'Evolution de Montpellier (UMR ISEM), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre National de la Recherche Scientifique (CNRS)-Institut de recherche pour le développement [IRD] : UR226, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Paul Scherrer Institute (PSI), Istituto di Scienze dell'Atmosfera e del Clima [Bologna] (ISAC), Consiglio Nazionale delle Ricerche (CNR), Leonelli, Giovanni, Battipaglia, Giovanna, Cherubini, Paolo, Saurer, Matthia, Siegwolf, Rolf T. W., Maugeri, Maurizio, Stenni, Barbara, Fusco, Stella, Maggi, Valter, and Pelfini, Manuela
Subjects: 0106 biological sciences, Dendroclimatology, Dendroecology, European larch, Stable isotopes, Tree rings, Environmental Engineering, Environmental Chemistry, Waste Management and Disposal, Pollution, 010504 meteorology & atmospheric sciences, δ18O, Growing season, 01 natural sciences, Dendrochronology, Glacial period, tree rings, stable isotopes, glaciers, European Alps, 0105 earth and related environmental sciences, Hydrology, biology, European Larch, 15. Life on land, Snow, biology.organism_classification, Stable isotope, 13. Climate action, Settore GEO/08 - Geochimica e Vulcanologia, [SDE]Environmental Sciences, Physical geography, Larch, Tree ring, Geology, 010606 plant biology & botany
Abstract: International audience; We analyzed the chronologies of cellulose stable isotopes (δ13C and δ18O) and tree-ring widths from European larch (Larix decidua) in a high-altitude site (2190ma.s.l.) at the bottom of a glacial valley in the Italian Alps, and investigated their dependence on monthly meteorological variables and δ18O precipitation values. The δ18O of tree-ring cellulose appears to be strongly driven by the δ18O of winter snowfall (November to March), which suggests that larch trees mostly use the snow-melt water of the previous winter during the growing season. This water, which also comes from the slope streams and from the underground flow of nearby steep slopes, infiltrates the soil in the valley bottom. The tree-ring cellulose δ18O values were also found to be influenced by the August precipitation δ18O and mean temperature. The associated regression model shows that the δ18O chronology from the tree rings explains up to 34% of the variance in the winter precipitation δ18O record, demonstrating the potential for reconstructing the δ18O isotopic composition of past winter precipitation in the study region. Unlike most other tree-ring studies that focus on growing season signals, in our study the summer signal was small and the winter signal dominant due to the special conditions of the glacial valley. Site topography, geomorphology and soil characteristics in particular influence the stable isotope signal in tree-ring cellulose.
Published: 2017

76. A global multiproxy database for temperature reconstructions of the Common Era

Author: Dmitry Divine, Dmitriy V. Ovchinnikov, Hugues Goosse, Marit-Solveig Seidenkrantz, Anne Hormes, Narayan Prasad Gaire, Joelle Gergis, Katrine Husum, David J. Nash, Konrad Gajewski, Jens Zinke, Vladimir Mikhalenko, Darrell S. Kaufman, Eugene R. Wahl, Martin Grosjean, Nancy A. N. Bertler, Pierre Francus, Anastasia Gornostaeva, Diana Vladimirova, Kaustubh Thirumalai, Lucien von Gunten, Kevin J. Anchukaitis, Michael Sigl, Ryu Uemura, Michael N. Evans, Hideaki Motoyama, Scott St. George, Marie-Alexandrine Sicre, Chris S. M. Turney, Johannes P. Werner, Robert Mulvaney, Jianghao Wang, Brian M. Chase, Mark A. J. Curran, Julien Emile-Geay, Takeshi Nakatsuka, David J. Sauchyn, Nerilie J. Abram, Bronwyn C. Dixon, Raphael Neukom, Cody C. Routson, Trevor J. Porter, Selvaraj Kandasamy, Mirko Severi, Massimo Frezzotti, Steven J. Phipps, Hans W. Linderholm, A. E. Viau, P. Graham Mortyn, Jessica E. Tierney, Eric J. Steig, Heidi A. Roop, K. Halimeda Kilbourne, Jason A. Addison, Jonathan J. Tyler, Mandy Freund, Daniel A. Dixon, Belen Martrat, Chenxi Xu, Krystyna M. Saunders, Min Te Chen, Xuemei Shao, Vasile Ersek, Philipp Munz, Hans Oerter, Masaki Sano, Zhixin Hao, Meloth Thamban, Alexey A. Ekaykin, Barbara Stenni, Kazuho Horiuchi, Ignacio A. Mundo, Zicheng Yu, Gregory T. Pederson, James W. C. White, Nalan Koc, Elisabeth Isaksson, Kathryn Allen, Rixt de Jong, Jeannine-Marie St. Jacques, Andrew Lorrey, Guillaume Leduc, Quansheng Ge, Kristine L. DeLong, Kenji Kawamura, Anais Orsi, Thomas Opel, Edward R. Cook, Kate E. Sinclair, Benjamin J. Henley, Nicholas P. McKay, Helen McGregor, Andrew D. Moy, Elizabeth R. Thomas, Jesper Björklund, Helena L. Filipsson, Udya Kuwar Thapa, Casey Saenger, Northern Arizona University [Flagstaff], Australian National University (ANU), United States Geological Survey [Reston] (USGS), University of Maryland [College Park], University of Maryland System, Spanish National Research Council [Madrid] (CSIC), School of Biological, Earth and Environmental Sciences [Sydney] (BEES), University of New South Wales [Sydney] (UNSW), Oeschger Centre for Climate Change Research (OCCR), University of Bern, Dipartimento di Scienze Geologiche [Trieste], Università degli studi di Trieste, University of Texas at Austin [Austin], Department of Earth and Space Sciences [Seattle], University of Washington [Seattle], Department of Earth Sciences [Oxford], University of Oxford [Oxford], Institut des Sciences de l'Evolution de Montpellier (UMR ISEM), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École pratique des hautes études (EPHE)-Université de Montpellier (UM)-Institut de recherche pour le développement [IRD] : UR226-Centre National de la Recherche Scientifique (CNRS), Climate Change Institute (CCI), University of Maine, University of Northumbria at Newcastle [United Kingdom], Lund University [Lund], Centre Eau Terre Environnement - INRS (INRS-ETE), Institut National de la Recherche Scientifique [Québec] (INRS), Italian National agency for new technologies, Energy and sustainable economic development [Frascati] (ENEA), Nepal Academy of Science and Technology, Université Catholique de Louvain (UCL), Quaternary Geology, The University Centre in Svalbard (UNIS), Norwegian Polar Institute, Climate and Environmental Physics [Bern] (CEP), Physikalisches Institut [Bern], Universität Bern [Bern]-Universität Bern [Bern], University of Maryland Center for Environmental Science, Horn Point Laboratory, Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Universitat Autònoma de Barcelona [Barcelona] (UAB), National Institute of Polar Research [Tokyo] (NiPR), British Antarctic Survey (BAS), Natural Environment Research Council (NERC), School of Environment and Technology, University of Brighton, Abteilung Klinische Sozialmedizin, Berufs- und Umweltdermatologie, Universität Heidelberg [Heidelberg], Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), 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), The University of Tokyo, Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Université Panthéon-Sorbonne (UP1), Aarhus University [Aarhus], Department of Chemistry, University of Florence (UNIFI), Biogéochimie-Traceurs-Paléoclimat (BTP), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN), Paul Scherrer Institute (PSI), University of the Ryukyus [Okinawa], Australian Institute of Marine Science (AIMS), PAGES 2k, Università degli studi di Trieste = University of Trieste, University of Oxford, Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Institut de recherche pour le développement [IRD] : UR226-Centre National de la Recherche Scientifique (CNRS), Climate Change Institute [Orono] (CCI), Centre Eau Terre Environnement [Québec] (INRS - ETE), Université Catholique de Louvain = Catholic University of Louvain (UCL), Universität Bern [Bern] (UNIBE)-Universität Bern [Bern] (UNIBE), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Universitat Autònoma de Barcelona (UAB), Universität Heidelberg [Heidelberg] = Heidelberg University, 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), The University of Tokyo (UTokyo), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Firenze = University of Florence (UniFI), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-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 Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École pratique des hautes études (EPHE), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), 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), Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-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 Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Emile-Geay, J., Mckay, N. P., Kaufman, D. S., Von Gunten, L., Wang, Junrong, Anchukaitis, K. J., Abram, N. J., Addison, J. A., Curran, M. A. J., Evans, M. N., Henley, B. J., Hao, Z., Martrat, B., Mcgregor, H. V., Neukom, R., Pederson, G. T., Stenni, B., Thirumalai, K., Werner, J. P., Xu, C., Divine, D. V., Dixon, B. C., Gergis, J., Mundo, I. A., Nakatsuka, T., Phipps, S. J., Routson, C. C., Steig, E. J., Tierney, J. E., Tyler, J. J., Allen, K. J., Bertler, N. A. N., Bjorklund, J., Chase, B. M., Chen, M. -T., Cook, E., De Jong, R., Delong, K. L., Dixon, D. A., Ekaykin, A. A., Ersek, V., Filipsson, H. L., Francus, P., Freund, M. B., Frezzotti, M., Gaire, N. P., Gajewski, K., Ge, Q., Goosse, H., Gornostaeva, A., Grosjean, M., Horiuchi, K., Hormes, A., Husum, K., Isaksson, E., Kandasamy, S., Kawamura, K., Kilbourne, K. H., Koc, N., Leduc, G., Linderholm, H. W., Lorrey, A. M., Mikhalenko, V., Mortyn, P. G., Motoyama, H., Moy, A. D., Mulvaney, R., Munz, P. M., Nash, D. J., Oerter, H., Opel, T., Orsi, A. J., Ovchinnikov, D. V., Porter, T. J., Roop, H. A., Saenger, C., Sano, M., Sauchyn, D., Saunders, K. M., Seidenkrantz, M. -S., Severi, M., Shao, X., Sicre, M. -A., Sigl, M., Sinclair, K., St George, S., St Jacques, J. -M., Thamban, M., Thapa, U. K., Thomas, E. R., Turney, C., Uemura, R., Viau, A. E., Vladimirova, D. O., Wahl, E. R., White, J. W. C., Yu, Z., Zinke, J., École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre National de la Recherche Scientifique (CNRS)-Institut de recherche pour le développement [IRD] : UR226, and UCL - SST/ELI/ELIC - Earth & Climate
Subjects: Data Descriptor, 010504 meteorology & atmospheric sciences, VDP::Mathematics and natural science: 400::Mathematics: 410::Statistics: 412, VDP::Matematikk og Naturvitenskap: 400::Matematikk: 410::Statistikk: 412, F800, computer.software_genre, Palaeoclimate, 01 natural sciences, Proxy (climate), CECI [CISM], calcification, data integration objective, Climate change, trace metal analysis, 910 Geography & travel, geography.geographical_feature_category, Database, G500, data acquisition system, temperature of environmental material, Computer Science Applications, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, Temperature reconstruction, Statistics, Probability and Uncertainty, Tree ring, Geology, wood, Information Systems, Statistics and Probability, glacial ice, radiance, 010506 paleontology, observation design, Library and Information Sciences, archaeal metabolite, Education, time series design, stable isotope analysis, Dendrochronology, 550 Earth sciences & geology, 0105 earth and related environmental sciences, geography, Global temperature, Glacier, 15. Life on land, Sea surface temperature, sediment, 13. Climate action, North Atlantic oscillation, Oceanic basin, computer
Abstract: Reproducible climate reconstructions of the Common Era (1 CE to present) are key to placing industrial-era warming into the context of natural climatic variability. Here we present a community-sourced database of temperature-sensitive proxy records from the PAGES2k initiative. The database gathers 692 records from 648 locations, including all continental regions and major ocean basins. The records are from trees, ice, sediment, corals, speleothems, documentary evidence, and other archives. They range in length from 50 to 2000 years, with a median of 547 years, while temporal resolution ranges from biweekly to centennial. Nearly half of the proxy time series are significantly correlated with HadCRUT4.2 surface temperature over the period 1850-2014. Global temperature composites show a remarkable degree of coherence between high- and low-resolution archives, with broadly similar patterns across archive types, terrestrial versus marine locations, and screening criteria. The database is suited to investigations of global and regional temperature variability over the Common Era, and is shared in the Linked Paleo Data (LiPD) format, including serializations in Matlab, R and Python., PAGES, a core project of Future Earth, is supported by the U.S. and Swiss National Science Foundations. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Some of this work was conducted as part of the North America 2k Working Group supported by the John Wesley Powell Center for Analysis and Synthesis, funded by the U.S. Geological Survey. B. Bauer, W. Gross, and E. Gille (NOAA National Centers for Environmental Information) are gratefully acknowledged for helping assemble the data citations and creating the NCEI versions of the PAGES 2k data records. We thank all the investigators whose commitment to data sharing enables the open science ethos embodied by this project.
Published: 2017

77. What controls the isotopic composition of Greenland surface snow?

Author: Arny E. Sveinbjörnsdottir, Marie Dumont, Camille Risi, Sepp Kipfstuhl, Frédéric Prié, Kazuhide Satow, Myriam Guillevic, Amaelle Landais, Dorthe Dahl-Jensen, Eric Brun, Renato Winkler, Kurt M. Cuffey, Motohiro Hirabayashi, Valérie Masson-Delmotte, Nicolas Bayou, Konrad Steffen, Trevor Popp, Barbara Stenni, Hans Christian Steen-Larsen, H. C., Steen Larsen, V., Masson Delmotte, M., Hirabayashi, R., Winkler, K., Satow, F., Prié, N., Bayou, E., Brun, K. M., Cuffey, D., Dahl Jensen, M., Dumont, M., Guillevic, S., Kipfstuhl, A., Landai, T., Popp, C., Risi, K., Steffen, Stenni, Barbara, A. E., Sveinbjörnsdottír, 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), Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado [Boulder]-National Oceanic and Atmospheric Administration (NOAA), 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), 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), National Institute of Polar Research [Tokyo] (NiPR), Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Berkeley Atmospheric Sciences Center (BASC), University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Department of Geological, Environmental and Marine Sciences [Trieste], Università degli studi di Trieste = University of Trieste, Institute of Earth Sciences [Reykjavik], University of Iceland [Reykjavik], 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), 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), 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), Groupe d'étude de l'atmosphère météorologique (CNRM-GAME), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), University of California [Berkeley], University of California-University of California, Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), and Università degli studi di Trieste
Subjects: water stable isotopes, water vapor, Greenland, 010504 meteorology & atmospheric sciences, δ18O, lcsh:Environmental protection, Stratigraphy, 010502 geochemistry & geophysics, Atmospheric sciences, 01 natural sciences, lcsh:Environmental pollution, Ice core, lcsh:TD169-171.8, lcsh:Environmental sciences, 0105 earth and related environmental sciences, lcsh:GE1-350, water stable isotope, Global and Planetary Change, Atmospheric models, Stable isotope ratio, Paleontology, Snow, Deuterium, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, 13. Climate action, Climatology, lcsh:TD172-193.5, Sublimation (phase transition), Geology, Water vapor
Abstract: Water stable isotopes in Greenland ice core data provide key paleoclimatic information, and have been compared with precipitation isotopic composition simulated by isotopically enabled atmospheric models. However, post-depositional processes linked with snow metamorphism remain poorly documented. For this purpose, monitoring of the isotopic composition (δ18O, δD) of near-surface water vapor, precipitation and samples of the top (0.5 cm) snow surface has been conducted during two summers (2011–2012) at NEEM, NW Greenland. The samples also include a subset of 17O-excess measurements over 4 days, and the measurements span the 2012 Greenland heat wave. Our observations are consistent with calculations assuming isotopic equilibrium between surface snow and water vapor. We observe a strong correlation between near-surface vapor δ18O and air temperature (0.85 ± 0.11‰ °C−1 (R = 0.76) for 2012). The correlation with air temperature is not observed in precipitation data or surface snow data. Deuterium excess (d-excess) is strongly anti-correlated with δ18O with a stronger slope for vapor than for precipitation and snow surface data. During nine 1–5-day periods between precipitation events, our data demonstrate parallel changes of δ18O and d-excess in surface snow and near-surface vapor. The changes in δ18O of the vapor are similar or larger than those of the snow δ18O. It is estimated using the CROCUS snow model that 6 to 20% of the surface snow mass is exchanged with the atmosphere. In our data, the sign of surface snow isotopic changes is not related to the sign or magnitude of sublimation or deposition. Comparisons with atmospheric models show that day-to-day variations in near-surface vapor isotopic composition are driven by synoptic variations and changes in air mass trajectories and distillation histories. We suggest that, in between precipitation events, changes in the surface snow isotopic composition are driven by these changes in near-surface vapor isotopic composition. This is consistent with an estimated 60% mass turnover of surface snow per day driven by snow recrystallization processes under NEEM summer surface snow temperature gradients. Our findings have implications for ice core data interpretation and model–data comparisons, and call for further process studies.
Published: 2014

78. Wrangling data from short Antarctic ice cores

Author: Barbara Stenni and Elizabeth R. Thomas
Subjects: Oceanography, Ice core, Geology
Published: 2018

79. Estimation of soil water evaporative loss after tillage operation using the stable isotope technique

Author: Toyin A. Arowolo, G. M. Zuppi, C. Tuniz, Barbara Stenni, F. K. Salako, M. T. Adetunji, M. A. Busari, M. A., Busari, F. K., Salako, C., Tuniz, G. M., Zuppi, Stenni, Barbara, M. T., Adetunji, and T. A., Arowolo
Subjects: Fluid Flow and Transfer Processes, Hydrology, Tillage, Plant science, Stable isotope ratio, Soil water, water stable isotopes, Soil Science, General Agricultural and Biological Sciences, Water Science and Technology
Abstract: Application of stable isotopes in soil studies has improved quantitative evaluation of evaporation and other hydrological processes in soil. This study was carried out to determine the effect of tillage on evaporative loss of water from the soil. Zero tillage and conventional tillage were compared. Suction tubes were installed for soil water collection at the depths 0.15, 0.50, and 1.0 m by pumping soil water with a peristaltic pump. Soil water evaporation was estimated using stable isotopes of water. The mean isotopic composition of the soil water at 0.15 m soil depth were -1.15‰ (δ18O) and -0.75‰ (δD) and were highly enriched compared with the isotopic compositions of the site precipitation. Soil water stable isotopes (δ18O and δD) were more enriched near the surface under zero tillage while they were less negative down the profile under zero tillage. This suggests an occurrence of more evaporation and infiltration under conventional then zero tillage, respectively, because evaporative fractionation contributes to escape of lighter isotopes from liquid into the vapour phase leading to enrichment in heavy isotopes in the liquid phase. The annual evaporation estimated using the vapour diffusion equation ranges from 46-70 and 54-84 mm year-1 under zero and conventional tillage, respectively, indicating more evaporation under conventional tillage compared with zero tillage. Therefore, to reduce soil water loss, adoption of conservation tillage practices such as zero tillage is encouraged.
Published: 2013

80. Continental-scale temperature variability during the past two millennia

Author: Robert Mulvaney, Nicholas E. Graham, Sebastian Wagner, Mirko Severi, Steven J. Phipps, Narayan Prasad Gaire, Fredrik Charpentier Ljungqvist, Darrell S. Kaufman, Martina Braida, Anne-Marie Lézine, Jason E. Smerdon, Ignacio A. Mundo, Danny McCarroll, Brendan M. Buckley, Mariano S. Morales, Joelle Gergis, Joseph R. McConnell, Koh Yasue, Valerie Trouet, Stefan W. Grab, Valérie Masson-Delmotte, Rochelle Graham, Moinuddin Ahmed, Edward R. Cook, Meloth Thamban, Henry F. Diaz, Eric J. Steig, David J. Nash, James W. C. White, Sharon E. Nicholson, Eduardo Zorita, Brian M. Chase, Jan Esper, Andrew Lorrey, Xuemei Shao, Andrew D. Moy, Dirk Verschuren, A. E. Viau, Duncan A. Christie, Quansheng Ge, Chris S. M. Turney, H. P. Borgaonkar, J. Fidel González-Rouco, Feng Shi, Asfawossen Asrat, Barbara Stenni, Jonathan G. Palmer, Tas van Ommen, Masaki Sano, Michael Sigl, Andrés Rivera, Antonio Lara, Ulf Büntgen, Mark A. J. Curran, Raphael Neukom, Bo Møllesøe Vinther, Ricardo Villalba, Mohammed Umer, Eugene R. Wahl, Martin Grosjean, Sami Hanhijärvi, Thorsten Kiefer, Jürg Luterbacher, Katsuhiko Kimura, Olga Solomina, Heinz Wanner, Paul J. Krusic, Lucien von Gunten, Kevin J. Anchukaitis, María Prieto, Ze-Xin Fan, Takeshi Nakatsuka, Timothy M. Shanahan, Atte Korhola, Nicholas P. McKay, Hans Oerter, Johannes P. Werner, Hugues Goosse, M., Ahmed, K. J., Anchukaiti, A., Asrat, H. P., Borgaonkar, Braida, Martina, B. M., Buckley, U., Büntgen, B. M., Chase, D. A., Christie, E. R., Cook, M. A. J., Curran, H. F., Diaz, J., Esper, Z. X., Fan, N. P., Gaire, Q., Ge, J., Gergi, J. F., González Rouco, H., Goosse, S. W., Grab, N., Graham, R., Graham, M., Grosjean, S. T., Hanhijärvi, D. S., Kaufman, T., Kiefer, K., Kimura, A. A., Korhola, P. J., Krusic, A., Lara, A. M., Lézine, F. C., Ljungqvist, A. M., Lorrey, J., Luterbacher, V., Masson Delmotte, D., Mccarroll, J. R., Mcconnell, N. P., Mckay, M. S., Morale, A. D., Moy, R., Mulvaney, I. A., Mundo, T., Nakatsuka, D. J., Nash, R., Neukom, S. E., Nicholson, H., Oerter, J. G., Palmer, S. J., Phipp, M. R., Prieto, A., Rivera, M., Sano, M., Severi, T. M., Shanahan, X., Shao, F., Shi, M., Sigl, J. E., Smerdon, O. N., Solomina, E. J., Steig, Stenni, Barbara, M., Thamban, V., Trouet, C. S. M., Turney, M., Umer, T., van Ommen, D., Verschuren, A. E., Viau, R., Villalba, B. M., Vinther, L., von Gunten, S., Wagner, E. R., Wahl, H., Wanner, J. P., Werner, J. W. C., White, K., Yasue, E., Zorita, Institut d'Astronomie et de Géophysique Georges Lemaître (UCL-ASTR), Université Catholique de Louvain = Catholic University of Louvain (UCL), Hydrologic Research Center, Paléoclimats, proxies, processus (PALEOPROXUS), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-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 Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), 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), Centro de Estudios Científicos (CECs), Departamento de Geografia [Santiago], Department of Chemistry, Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Department of Chemistry and Biochemistry, University of Bern, Dipartimento di Scienze Geologiche [Trieste], Università degli studi di Trieste, Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-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 Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), 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), and Università degli studi di Trieste = University of Trieste
Subjects: 010506 paleontology, PALAEOCLIMATE AND PALAEOCENOGRAPHY, Paleoclimate, 010504 meteorology & atmospheric sciences, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Climate change, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], 910 Geography & travel, 01 natural sciences, Ciencias de la Tierra y relacionadas con el Medio Ambiente, Investigación Climatológica, Centennial, 550 Earth sciences & geology, 540 Chemistry, Paleoclimatology, Ice age, Earth temperature, Southern Hemisphere, 0105 earth and related environmental sciences, CLIMATE SCIENCE, Atmosphere, Temperature, Little Ice Age, Medieval Warm Periods, Northern Hemisphere, Climatic changes, Scale (music), Climatology, Period (geology), 570 Life sciences, biology, General Earth and Planetary Sciences, CIENCIAS NATURALES Y EXACTAS, Geology
Abstract: Past global climate changes had strong regional expression. To elucidate their spatio-temporal pattern, we reconstructed past temperatures for seven continental-scale regions during the past one to two millennia. The most coherent feature in nearly all of the regional temperature reconstructions is a long-term cooling trend, which ended late in the nineteenth century. At multi-decadal to centennial scales, temperature variability shows distinctly different regional patterns, with more similarity within each hemisphere than between them. There were no globally synchronous multi-decadal warm or cold intervals that define a worldwide Medieval Warm Period or Little Ice Age, but all reconstructions show generally cold conditions between AD 1580 and 1880, punctuated in some regions by warm decades during the eighteenth century. The transition to these colder conditions occurred earlier in the Arctic, Europe and Asia than in North America or the Southern Hemisphere regions. Recent warming reversed the long-term cooling; during the period AD 1971?2000, the area-weighted average reconstructed temperature was higher than any other time in nearly 1,400 years. Fil: Ahmed, Moinuddin. Federal Urdu University of Arts, Science and Technology. Department of Botany; Pakistán Fil: Anchukaitis, Kevin J.. Columbia University. Lamont Doherty Earth Observatory; Estados Unidos. Woods Hole Oceanographic Institution; Estados Unidos Fil: Asrat, Asfawossen . Addis Ababa University. School of Earth Sciences; Etiopía Fil: Borgaonkar, Hemant P.. Indian Institute of Tropical Meteorology; India Fil: Braida, Martina . University of Trieste. Dipartimento di Matematica e Geoscienze; Italia Fil: Buckley, Brendan M. . Columbia University. Lamont Doherty Earth Observatory; Estados Unidos Fil: Ulf Büntgen. Swiss Federal Research Institute WSL; Suiza Fil: Chase, Brian M.. Université Montpellier. Département Paléoenvironnements et Paléoclimats (PAL); Francia. University of Bergen. Department of Archaeology, History, Cultural Studies and Religion; Noruega Fil: Christie, Duncan A. . Universidad Austral de Chile. Laboratorio de Dendrocronología y Cambio Global; Chile. Universidad de Chile. Center for Climate and Resilience Research; Chile Fil: Cook, Edward R.. Columbia University. Lamont Doherty Earth Observatory; Argentina Fil: Curran, Mark A. J.. Australian Antarctic Division; Australia. University of Tasmania. Antarctic Climate & Ecosystems Cooperative Research Centre; Australia Fil: Diaz, Henry F. . National Oceanic and Atmospheric Administration. Cooperative Institute for Research in Environmental Sciences, ; Estados Unidos Fil: Esper, Jan. Johannes Gutenberg University. Department of Geography,; Alemania Fil: Fan, Ze-Xin . Chinese Academy of Sciences. Xishuangbanna Tropical Botanical Garden ; China Fil: Gaire, Narayan P. . Nepal Academy of Science and Technology. Faculty of Science,; Nepal Fil: Ge, Quansheng. Chinese Academy of Sciences. Institute of Geographical Sciences and Natural Resources Research, ; China Fil: Gergis, Joëlle. University of Melbourne. School of Earth Sciences; Australia Fil: González-Rouco, J Fidel. Universidad Complutense de Madrid. Departamento Astrofísica y CC de la Atmósfera; España Fil: Goosse, Hugues. Université Catholique de Louvain. LemaitreCenter for Earth and Climate Research, Earth and Life Institute; Bélgica Fil: Grab, Stefan W. . University of the Witwatersrand. School of Geography,Archaeology and Environmental Studies; Sudáfrica Fil: Graham, Nicholas. Hydrologic Research Center; Estados Unidos Fil: Graham, Rochelle . Hydrologic Research Center; Estados Unidos Fil: Grosjean, Martin . University of Bern. Oeschger Centre for Climate Change Research & Institute of Geography; Suiza Fil: Hanhijärvi, Sami T.. University of Helsinki. Department of Environmental Sciences; Finlandia Fil: Kaufman, Darrell S.. Northern Arizona University. School of Earth Sciences and Environmental Sustainability; Estados Unidos Fil: Kiefer, Thorsten . International Project Office, Past Global Changes (PAGES); Suiza Fil: Kimura, Katsuhiko. Fukushima University. Department of Symbiotic System Science; Japón Fil: Korhola, Atte A.. University of Helsinki. Department of Environmental Sciences; Finlandia Fil: Krusic, Paul J.. Stockholm University. Department of Physical Geography and Quaternary Geology; Suecia Fil: Lara, Antonio. Universidad Austral de Chile. Laboratorio de Dendrocronología y Cambio Global; Chile. Universidad de Chile. Center for Climate and Resilience Research; Chile Fil: Lézine, Anne-Marie. Université Pierre et Marie Curie. Laboratoire d’Océanographie et du Climat: Expérimentations et Approches Numériques (LOCEAN); Francia Fil: Ljungqvist, Fredrik C.. Stockholm University. Department of History, ; Suecia Fil: Lorrey, Andrew M.. National Institute of Water and Atmospheric Research Ltd., National Climate Centre Auckland; Nueva Zelanda Fil: Luterbacher, Jürg. Justus Liebig University. Department of Geography, Climatology, Climate Dynamics and Climate Change; Alemania Fil: Masson-Delmotte, Valérie . Laboratoire des Science du Climat et de l’Environnement, Gif-sur-Yvette; Francia Fil: McCarroll, Danny. Swansea University. Department of Geography; Reino Unido Fil: McConnell, Joseph R.. Nevada System of Higher Education. Desert Research Institute; Estados Unidos Fil: McKay, Nicholas P.. Northern Arizona University. School of Earth Sciences and Environmental Sustainability; Estados Unidos Fil: Morales, Mariano Santos. Consejo Nacional de Investigaciones Científicas y Técnicas. Científico Tecnológico Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina Fil: Moy, Andrew D.. Australian Antarctic Division; Australia. University of Tasmania. Antarctic Climate & Ecosystems Cooperative Research Centre; Australia Fil: Mulvaney, Robert. British Antarctic Survey; Reino Unido Fil: Mundo, Ignacio Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Científico Tecnológico Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina Fil: Nakatsuka, Takeshi. Nagoya University. Department of Earth and Environmental Sciences; Japón Fil: Nash, David J.. University of the Witwatersrand. School of Geography,Archaeology and Environmental Studies; Sudáfrica. University of Brighton. School of Environment and Technology; Reino Unido Fil: Neukom, Raphael . Swiss Federal Research Institute WSL; Suiza Fil: Nicholson, Sharon E.. Florida State University. Department of Earth, Ocean and Atmospheric Sciences, ; Estados Unidos Fil: Oerter, Hans. Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association. Department of Glaciology; Alemania Fil: Palmer, Jonathan G.. University of Exeter. College of Life and Environmental Sciences; Reino Unido. University of New South Wales. Climate Change Research Centre; Australia Fil: Phipps, Steven J.. University of New South Wales. Climate Change Research Centre; Australia. University of New South Wales. ARC Centre of Excellence for Climate System Science; Australia Fil: Prieto, Maria del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Científico Tecnológico Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina Fil: Rivera, Andres. Centro de Estudios Cientificos; Chile Fil: Sano, Masaki. Nagoya University. Department of Earth and Environmental Sciences; Japón Fil: Severi, Mirko. University of Florence. Department of Chemistry ‘Ugo Schiff’; Italia Fil: Shanahan, Timothy M.. University of Texas at Austin. Jackson School of Geosciences; Estados Unidos Fil: Shao, Xuemei. Chinese Academy of Sciences. Institute of Geographical Sciences and Natural Resources Research; China Fil: Shi, Feng. Chinese Academy of Sciences. LASG, Institute of Atmospheric Physics, ; China Fil: Sigl, Michael . Nevada System of Higher Education. Desert Research Institute,; Estados Unidos Fil: Smerdon, Jason E.. Columbia University. Lamont Doherty Earth Observatory; Estados Unidos Fil: Solomina, Olga N. . Russian Academy of Sciences. Institute of Geography; Rusia Fil: Steig, Eric J.. University of Washington. Department of Earth and Space Sciences; Estados Unidos Fil: Stenni, Barbara. University of Trieste. Dipartimento di Matematica e Geoscienze; Italia Fil: Thamban, Meloth. National Centre for Antarctic and Ocean Research; India Fil: Trouet, Valerie. University of Arizona. Laboratory of Tree-Ring Research; Estados Unidos Fil: Turney, Chris S.M.. University of New South Wales. Climate Change Research Centre; Australia Fil: Umer, Mohammed. Addis Ababa University. School of Earth Sciences; Etiopía Fil: van Ommen, Tas. Australian Antarctic Division; Australia. University of Tasmania. Antarctic Climate & Ecosystems Cooperative Research Centre; Australia Fil: Verschuren, Dirk. Ghent University. Department of Biology; Bélgica Fil: Viau, Andre E.. University of Ottawa. Department of Geography; Canadá Fil: Villalba, Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Científico Tecnológico Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina Fil: Vinther, Bo M.. University of Copenhagen. Niels Bohr Institute; Dinamarca Fil: von Gunten, Lucien . Past Global Changes (PAGES). International Project Office, ; Suiza Fil: Wagner, Sebastian. Helmholtz-Zentrum Geesthacht. Institute for Coastal Research; Alemania Fil: Wahl, Eugene R.. National Oceanic and Atmospheric Administration. National Climatic Data Center; Estados Unidos Fil: Wanner, Heinz. University of Bern. Oeschger Centre for Climate Change Research & Institute of Geography; Suiza Fil: Werner, Johannes P.. Justus Liebig University. Department of Geography, Climatology, Climate Dynamics and Climate Change; Alemania Fil: White, James W.C.. University of Colorado. Institute of Arctic and Alpine Research; Estados Unidos Fil: Yasue, Koh. Shinshu University. Department of Forest Science; Japón Fil: Zorita, Eduardo. Helmholtz-Zentrum Geesthacht. Institute for Coastal Research; Alemania
Published: 2013

81. Supplementary material to 'Archival of the water stable isotope signal in East Antarctic ice cores'

Author: Mathieu Casado, Amaelle Landais, Ghislain Picard, Thomas Münch, Thomas Laepple, Barbara Stenni, Giuliano Dreossi, Alexey Ekaykin, Laurent Arnaud, Christophe Genthon, Alexandra Touzeau, Valérie Masson-Delmotte, and Jean Jouzel
Published: 2016

82. Archival of the water stable isotope signal in East Antarctic ice cores

Author: Valérie Masson-Delmotte, Laurent Arnaud, Mathieu Casado, Jean Jouzel, Alexey A. Ekaykin, Amaelle Landais, Giuliano Dreossi, Thomas Laepple, Alexandra Touzeau, Thomas Münch, Ghislain Picard, Christophe Genthon, and Barbara Stenni
Subjects: geography, geography.geographical_feature_category, 010504 meteorology & atmospheric sciences, Stable isotope ratio, 15. Life on land, 010502 geochemistry & geophysics, Atmospheric sciences, Snow, 01 natural sciences, Ice core, 13. Climate action, Climatology, Paleoclimatology, Cryosphere, Climate model, Ice sheet, human activities, Geology, Water vapor, 0105 earth and related environmental sciences
Abstract: The oldest ice core records are obtained from the East Antarctic plateau. Water stable isotopes records are key for reconstructions of past climatic conditions both over the ice sheet and at the evaporation source. The accuracy of such climate reconstructions crucially depends on the knowledge of all the processes affecting the water vapour, precipitation and snow isotopic composition. Atmospheric fractionation processes are well understood and can be integrated in Rayleigh distillation and complex isotope enabled climate models. However, a comprehensive quantitative understanding of processes potentially altering the snow isotopic composition after the deposition is still missing, especially for exchanges between vapour and snow. In low accumulation sites such as found on the East Antarctic Plateau, these poorly constrained processes are especially likely to play a significant role. This limits the interpretation of isotopic composition from ice core records, specifically at short time scales. Here, we combine observations of isotopic composition in the vapour, the precipitation, the surface snow and the buried snow from various sites of the East Antarctic Plateau. At the seasonal scale, we highlight a significant impact of metamorphism on surface snow isotopic signal compared to the initial precipitation isotopic signal. In particular, in summer, exchanges of water molecules between vapour and snow are driven by the sublimation/condensation cycles at the diurnal scale. Using highly resolved isotopic composition profiles from pits in five East Antarctic sites, we identify a common 20 cm cycle which cannot be attributed to the seasonal variability of precipitation. Altogether, the smaller range of isotopic compositions observed in the buried and in the surface snow compared to the precipitation, and also the reduced slope between surface snow isotopic composition and temperature compared to precipitation, constitute evidences of post-deposition processes affecting the variability of the isotopic composition in the snow pack. To reproduce these processes in snow-models is crucial to understand the link between snow isotopic composition and climatic conditions and to improve the interpretation of isotopic composition as a paleoclimate proxy.
Published: 2016

83. Referee comment

Author: Barbara Stenni
Published: 2016

84. Authors answer to referees

Author: Barbara Stenni
Published: 2016

85. Larix decidua δ

Author: Giovanni, Leonelli, Giovanna, Battipaglia, Paolo, Cherubini, Matthias, Saurer, Rolf T W, Siegwolf, Maurizio, Maugeri, Barbara, Stenni, Stella, Fusco, Valter, Maggi, and Manuela, Pelfini
Subjects: Snow, Larix, Oxygen Isotopes, Cellulose, Environmental Monitoring
Abstract: We analyzed the chronologies of cellulose stable isotopes (δ
Published: 2016

86. Acquisition of isotopic composition for surface snow in East Antarctica and the links to climatic parameters

Author: Amaelle Landais, Emmanuel Le Meur, Joel Savarino, Shuji Fujita, Eugeni Barkan, Ryu Uemura, Mathieu Casado, Camille Risi, Mélanie Baroni, Sarah Guilbaud, Olivier Magand, Alexey A. Ekaykin, Grégory Teste, Kotaro Fukui, Alexandra Touzeau, Ilann Bourgeois, Boaz Luz, Barbara Stenni, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), 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), Departemanto di Scienze Ambientali Informatica e Statistica (DAIS), University of Ca’ Foscari [Venice, Italy], University of the Ryukyus [Okinawa], Tateyama Caldera Sabo Museum, The Graduate University for Advanced Studies, japan (SOKENDAI), National Institute of Polar Research [Tokyo] (NiPR), Laboratoire de Physico-Chimie de l'Atmosphère (LPCA), Université du Littoral Côte d'Opale, Saint Petersburg State Technical University, Saint Petersburg State Polytechnical University (SPSPU), Arctic and Antarctic Research Institute (AARI), Russian Federal Service for Hydrometeorology and Environmental Monitoring (Roshydromet), The Institute of Earth Sciences, The Hebrew University of Jerusalem (HUJ), Laboratoire de glaciologie et géophysique de l'environnement (LGGE), 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), Laboratoire d'Ecologie Alpine (LECA), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Université Joseph Fourier - Grenoble 1 (UJF)-Université Grenoble Alpes (UGA), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris)-École normale supérieure - Paris (ENS Paris), 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), Université du Littoral Côte d'Opale (ULCO), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), 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 Grenoble Alpes [2016-2019] (UGA [2016-2019])-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)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire d'Ecologie Alpine (LECA ), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), 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), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)
Subjects: 010504 meteorology & atmospheric sciences, WATER-STABLE ISOTOPES, DRONNING MAUD LAND, ACCUMULATION RATE, VOSTOK STATION, 010502 geochemistry & geophysics, Atmospheric sciences, 01 natural sciences, GENERAL-CIRCULATION MODEL, GLACIAL-INTERGLACIAL CHANGES, DEUTERIUM EXCESS SIGNAL, WATER-STABLE ISOTOPES, GREENLAND ICE CORES, DRONNING MAUD LAND, ACCUMULATION RATE, VOSTOK STATION, DOME-C, TEMPORAL VARIABILITY, GREENLAND ICE CORES, Dome (geology), Ice core, TEMPORAL VARIABILITY, DEUTERIUM EXCESS SIGNAL, Glacial period, Precipitation, GENERAL-CIRCULATION MODEL, [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology, lcsh:Environmental sciences, 0105 earth and related environmental sciences, Earth-Surface Processes, Water Science and Technology, lcsh:GE1-350, Moisture, lcsh:QE1-996.5, GLACIAL-INTERGLACIAL CHANGES, 15. Life on land, Snow, lcsh:Geology, 13. Climate action, Settore GEO/08 - Geochimica e Vulcanologia, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, Climatology, Kinetic fractionation, Stage (hydrology), DOME-C, Geology
Abstract: International audience; The isotopic compositions of oxygen and hydrogen in ice cores are invaluable tools for the reconstruction of past climate variations. Used alone, they give insights into the variations of the local temperature, whereas taken together they can provide information on the climatic conditions at the point of origin of the moisture. However, recent analyses of snow from shallow pits indicate that the climatic signal can become erased in very low accumulation regions, due to local processes of snow reworking. The signal-to-noise ratio decreases and the climatic signal can then only be retrieved using stacks of several snow pits. Obviously, the signal is not completely lost at this stage, otherwise it would be impossible to extract valuable climate information from ice cores as has been done, for instance, for the last glaciation. To better understand how the climatic signal is passed from the precipitation to the snow, we present here results from varied snow samples from East Antarctica. First, we look at the relationship between isotopes and temperature from a geographical point of view, using results from three traverses across Antarctica, to see how the relationship is built up through the distillation process. We also take advantage of these measures to see how second-order parameters (d-excess and 17 O-excess) are related to δ 18 O and how they are controlled. d-excess increases in the interior of the continent (i.e., when δ 18 O decreases), due to the distillation process, whereas 17 O-excess decreases in remote areas, due to kinetic fractionation at low temperature. In both cases, these changes are associated with the loss of original information regarding the source. Then, we look at the same relationships in precipitation samples collected over 1 year at Dome C and Vos-tok, as well as in surface snow at Dome C. We note that the slope of the δ 18 O vs. temperature (T) relationship decreases in these samples compared to those from the traverses, and thus caution is advocated when using spatial slopes for past Published by Copernicus Publications on behalf of the European Geosciences Union. 838 A. Touzeau et al.: Acquisition of isotopic composition for surface snow in East Antarctica climate reconstruction. The second-order parameters behave in the same way in the precipitation as in the surface snow from traverses, indicating that similar processes are active and that their interpretation in terms of source climatic parameters is strongly complicated by local temperature effects in East Antarctica. Finally we check if the same relationships between δ 18 O and second-order parameters are also found in the snow from four snow pits. While the d-excess remains opposed to δ 18 O in most snow pits, the 17 O-excess is no longer positively correlated to δ 18 O and even shows anti-correlation to δ 18 O at Vostok. This may be due to a strato-spheric influence at this site and/or to post-deposition processes .
Published: 2016

87. Assessing recent trends in high-latitude Southern Hemisphere surface climate

Author: Xavier Crosta, Julie M. Jones, Nerilie J. Abram, Adele K. Morrison, Matthew H. England, Hugues Goosse, Anais Orsi, Kyle R. Clem, Eric J. Steig, Tessa Vance, Sarah T. Gille, James A. Renwick, Dan J. Charman, Ryan L. Fogt, Marilyn N. Raphael, Pablo O. Canziani, Graham Simpkins, Casimir de Lavergne, Leela M. Frankcombe, Barbara Stenni, David P. Schneider, Gareth J. Marshall, Ian Eisenman, Didier Swingedouw, Valérie Masson-Delmotte, Department of Geography [Sheffield], University of Sheffield [Sheffield], Scripps Institution of Oceanography (SIO), University of California [San Diego] (UC San Diego), University of California-University of California, Institut d'Astronomie et de Géophysique Georges Lemaître (UCL-ASTR), Université Catholique de Louvain = Catholic University of Louvain (UCL), Australian National University (ANU), Environnements et Paléoenvironnements OCéaniques (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Nucleus for European Modeling of the Ocean (NEMO R&D ), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-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 Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), School of Computing, Electronics and Mathematics [Coventry], Faculty of Engineering, Environment and Computing [Coventry], Coventry University -Coventry University, 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), National Center for Atmospheric Research [Boulder] (NCAR), University of Ca’ Foscari [Venice, Italy], Scripps Institution of Oceanography (SIO - UC San Diego), University of California (UC)-University of California (UC), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-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 Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), 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), and 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)
Subjects: 010504 meteorology & atmospheric sciences, Environmental Science (miscellaneous), Social Sciences (miscellaneous), Environmental Science and Management, CLIMATE CHANGE, Magnitude (mathematics), Climate change, Context (language use), Forcing (mathematics), 010502 geochemistry & geophysics, 01 natural sciences, Physical Geography and Environmental Geoscience, Ciencias de la Tierra y relacionadas con el Medio Ambiente, Atmospheric Sciences, Investigación Climatológica, Atmosphere, CLIMATE VARIABILITY, 14. Life underwater, Southern Hemisphere, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, 0105 earth and related environmental sciences, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Mode (statistics), Climate Action, ANTARCTICA, 13. Climate action, Settore GEO/08 - Geochimica e Vulcanologia, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, Climatology, Environmental science, Climate model, CIENCIAS NATURALES Y EXACTAS
Abstract: Understanding the causes of recent climatic trends and variability in the high-latitude Southern Hemisphere is hampered by a short instrumental record. Here, we analyse recent atmosphere, surface ocean and sea-ice observations in this region and assess their trends in the context of palaeoclimate records and climate model simulations. Over the 36-year satellite era, significant linear trends in annual mean sea-ice extent, surface temperature and sea-level pressure are superimposed on large interannual to decadal variability. Most observed trends, however, are not unusual when compared with Antarctic palaeoclimate records of the past two centuries. With the exception of the positive trend in the Southern Annular Mode, climate model simulations that include anthropogenic forcing are not compatible with the observed trends. This suggests that natural variability overwhelms the forced response in the observations, but the models may not fully represent this natural variability or may overestimate the magnitude of the forced response. Fil: Jones, Julie. University of Sheffield; Reino Unido Fil: Gille, Sarah. University of California at San Diego. Scripps Institution of Oceanography; Estados Unidos Fil: Goose, Hugues J.. Université Catholique de Louvain; Bélgica Fil: Abram, Nerillie J.. The Australian National University; Australia Fil: Canziani, Pablo Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Tecnológica Nacional. Facultad Regional Buenos Aires. Unidad de Investigación y Desarrollo de las Ingenierías; Argentina Fil: Charman, Dan J.. University of Exeter; Reino Unido Fil: Clem, Kyle R.. Victoria University of Wellington; Nueva Zelanda Fil: Crosta Xavier. Universite de Bordeaux; Francia Fil: de Lavergne, Casimir. Université Pierre et Marie Curie; Francia Fil: Eisenman, Ian. University of California at San Diego. Scripps Institution of Oceanography; Estados Unidos Fil: England, Matthew H.. University of New South Wales; Australia Fil: Fogt, Ryan L.. Ohio University; Estados Unidos Fil: Frankcombe, Leela M.. University of New South Wales; Australia Fil: Marshall, Gareth J.. British Antartic Survey; Reino Unido Fil: Masson Delmotte, Valérie. Université de Paris-Saclay; Francia. Centre National de la Recherche Scientifique; Francia Fil: Morrison, Adele K.. University of Princeton; Estados Unidos Fil: Orsi, Anaïs J.. Université de Paris-Saclay; Francia Fil: Raphael, Marilyn N.. University of California; Estados Unidos Fil: Renwick, James A.. Victoria University of Wellington; Nueva Zelanda Fil: Schneider, David P.. National Center for Atmospheric Research; Estados Unidos Fil: Simpkins, Graham R.. University of California at Irvine. School of Physical Sciences. Department of Earth System Sciences; Estados Unidos Fil: Steig, Eric J.. University of Washington; Estados Unidos Fil: Steni, Barbara. Universita' Ca' Foscari Di Venezia; Italia Fil: Swingedow, Didier. Universite de Bordeaux; Francia Fil: Vance, Tessa R.. Antarctic Climate and Ecosystems Cooperative Research Centre; Australia
Published: 2016

88. Age of the Mt. Ortles ice cores, the Tyrolean Iceman and glaciation of the highest summit of South Tyrol since the Northern Hemisphere Climatic Optimum

Author: Olivier Magand, Natalie Kehrwald, R. Dinale, Chiara Uglietti, Piero Zennaro, Federico Cazorzi, Fabrizio de Blasi, Gianni Piffer, Daniela Festi, Stephan Galos, Michele Bertò, David Tonidandel, Andrea Spolaor, Barbara Stenni, Theo M. Jenk, Vladimir Mikhalenko, Luca Carturan, Petra Heidenwolf, Ulrich Schotterer, Mirko Rinaldi, Giuliano Dreossi, Margit Schwikowski, Mary E. Davis, Carlo Barbante, Klaus Oeggl, Thomas Zanoner, Paolo Gabrielli, G. Dragà, Roberto Seppi, Jacopo Gabrieli, Ping Nan Lin, Volkmar Mair, Daniel Binder, Massimo Frezzotti, V. Zagorodnov, Alberto Carton, Donald V. Kenny, Giancarlo Dalla Fontana, Giulio Cozzi, Giuliano Bertagna, Patrick Ginot, Gabrielli, P., Barbante, C., Bertagna, G., Berto, M., Binder, D., Carton, A., Carturan, L., Cazorzi, F., Cozzi, G., Dalla Fontana, G., Davis, M., De Blasi, F., Dinale, R., Draga, G., Dreossi, G., Festi, D., Frezzotti, M., Gabrieli, J., Galos, S., Ginot, P., Heidenwolf, P., Jenk, T. M., Kehrwald, N., Kenny, D., Magand, O., Mair, V., Mikhalenko, V., Lin, P. N., Oeggl, K., Piffer, G., Rinaldi, M., Schotterer, U., Schwikowski, M., Seppi, R., Spolaor, A., Stenni, B., Tonidandel, D., Uglietti, C., Zagorodnov, V., Zanoner, T., and Zennaro, P.
Subjects: Water Science and Technology, Earth-Surface Processes, 010506 paleontology, 010504 meteorology & atmospheric sciences, Ice stream, Ice field, ice cores, alps, 01 natural sciences, Ice core, paleoclimate, Cryosphere, Geomorphology, lcsh:Environmental sciences, 0105 earth and related environmental sciences, lcsh:GE1-350, geography, geography.geographical_feature_category, lcsh:QE1-996.5, Glacier, Glacier morphology, Arctic ice pack, lcsh:Geology, Settore GEO/08 - Geochimica e Vulcanologia, 13. Climate action, Physical geography, Ice sheet, Geology
Abstract: In 2011 four ice cores were extracted from the summit of Alto dell'Ortles (3859 m), the highest glacier of South Tyrol in the Italian Alps. This drilling site is located only 37 km southwest from where the Tyrolean Iceman, ∼ 5.3 kyrs old, was discovered emerging from the ablating ice field of Tisenjoch (3210 m, near the Italian–Austrian border) in 1991. The excellent preservation of this mummy suggested that the Tyrolean Iceman was continuously embedded in prehistoric ice and that additional ancient ice was likely preserved elsewhere in South Tyrol. Dating of the ice cores from Alto dell'Ortles based on 210Pb, tritium, beta activity and 14C determinations, combined with an empirical model (COPRA), provides evidence for a chronologically ordered ice stratigraphy from the modern glacier surface down to the bottom ice layers with an age of ∼ 7 kyrs, which confirms the hypothesis. Our results indicate that the drilling site has continuously been glaciated on frozen bedrock since ∼ 7 kyrs BP. Absence of older ice on the highest glacier of South Tyrol is consistent with the removal of basal ice from bedrock during the Northern Hemisphere Climatic Optimum (6–9 kyrs BP), the warmest interval in the European Alps during the Holocene. Borehole inclinometric measurements of the current glacier flow combined with surface ground penetration radar (GPR) measurements indicate that, due to the sustained atmospheric warming since the 1980s, an acceleration of the glacier Alto dell'Ortles flow has just recently begun. Given the stratigraphic–chronological continuity of the Mt. Ortles cores over millennia, it can be argued that this behaviour has been unprecedented at this location since the Northern Hemisphere Climatic Optimum.
Published: 2016

89. Technical Note: Evaluation of between-sample memory effects in the analysis of δ2H and δ18O of water samples measured by laser spectroscopes

Author: Giulia Zuecco, Leonard I. Wassenaar, Barbara Stenni, S. Wrede, Thom Bogaard, Martin Šanda, Marzia Michelini, A. Gobbi, Mattia Bonazza, Benjamin Fischer, Daniele Penna, M. Sobotková, N. Mantese, Marco Borga, and B. Cejková
Subjects: Nuclear magnetic resonance, Spectrometer, Isotope, Chemistry, δ18O, law, Sample (material), Analytical chemistry, Laser, Spectroscopy, Standard deviation, Isotope analysis, law.invention
Abstract: This study evaluated between-sample memory in isotopic measurements of δ2H and δ18O in water samples by laser spectroscopy. Ten isotopically depleted water samples spanning a broad range of oxygen and hydrogen isotopic compositions were measured by three generations of off-axis integrated cavity output spectroscopy and cavity ring-down spectroscopy instruments. The analysis procedure encompassed small (less than 2‰ for δ2H and 1‰ for δ18O) and large (up to 201‰ for δ2H and 25‰ for δ18O) differences in isotopic compositions between adjacent sample vials. Samples were injected 18 times each, and the between-sample memory effect was quantified for each analysis run. Results showed that samples adversely affected by between-sample isotopic differences stabilised after seven–eight injections. The between-sample memory effect ranged from 14% and 9% for δ2H and δ18O measurements, respectively, but declined to negligible carryover (between 0.1% and 0.3% for both isotopes) when the first ten injections of each sample were discarded. The measurement variability (range and standard deviation) was strongly dependent on the isotopic difference between adjacent vials. Standard deviations were up to 7.5‰ for δ2H and 0.54‰ for δ18O when all injections were retained in the computation of the reportable δ-value, but a significant increase in measurement precision (standard deviation in the range 0.1‰–1.0‰ for δ2H and 0.05‰–0.17‰ for δ18O) was obtained when the first eight injections were discarded. In conclusion, this study provided a practical solution to mitigate between-sample memory effects in the isotopic analysis of water samples by laser spectroscopy.
Published: 2012

90. Nitrate in Polar Ice: A New Tracer of Solar Variability

Author: Silvia Becagli, Barbara Stenni, Sami K. Solanki, Roberto Udisti, Ilya Usoskin, Massimo Frezzotti, Rita Traversi, Mirko Severi, Traversi, R., Usoskin, I. G., Solanki, S. K., Becagli, S., Frezzotti, M., Severi, M., Stenni, Barbara, Udisti, R., and Stenni, B.
Subjects: Cosmic rays, galactic, Holocene, ice core, nitrate, solar cycle, Ice core, Cosmic ray, Nitrate, Solar cycle, Atmospheric sciences, chemistry.chemical_compound, TRACER, Physics, Isotope, Firn, Astronomy and Astrophysics, chemistry, Space and Planetary Science, Cosmic rays, galactic
Abstract: Knowledge of the long-term variability of solar activity is of both astrophysical and geoscientific interest. Reconstructions of solar activity over multiple millennia are traditionally based on cosmogenic isotopes 14C or 10Be measured in natural terrestrial archives, but the two isotopes exhibit significant differences on millennial time scales, so that our knowledge of solar activity at this time scale remains somewhat uncertain. Here we present a new potential proxy of solar activity on the centennial-millennial time scale, based on a chemical tracer, viz. nitrate content in an ice core drilled at Talos Dome (Antarctica). We argue that this location is optimal for preserving the solar signal in the nitrate content during the Holocene. By using the firn core from the same location we show that the 11-year and Gleissberg cycles are present with the variability of 10 - 25 % in nitrate content in the pre-industrial epoch. This is consistent with the results of independent efforts of modeling HNO 3 and NO y in Antarctic near surface air. However, meteorological noise on the interannual scale makes it impossible to resolve individual solar cycles. Based on different processes of formation and transport compared to cosmogenic isotopes, it provides new, independent insight into long-term solar activity and helps resolve the uncertainties related to cosmogenic isotopes as diagnostics of solar activity. © 2012 Springer Science+Business Media B.V.
Published: 2012

91. Volcanic synchronisation of the EPICA-DC and TALDICE ice cores for the last 42 kyr BP

Author: Barbara Stenni, Roberto Udisti, Rita Traversi, Silvia Becagli, Mirko Severi, Severi, M., Udisti, R., Becagli, S., Stenni, Barbara, Traversi, R., and European Geosciences Union
Subjects: EPICA Dome C, TALDICE, sulphate records, volcanic eruptions, East Antarctica, ice cores, synchronisation, Scale (ratio), Stratigraphy, lcsh:Environmental protection, volcanic eruption, Dome (geology), Paleontology, Ice core, lcsh:Environmental pollution, Stage (stratigraphy), lcsh:TD169-171.8, Geomorphology, Holocene, lcsh:Environmental sciences, Talos Dome, lcsh:GE1-350, Global and Planetary Change, geography, geography.geographical_feature_category, biology, Sulphate, volcanic synchronization, age scale, biology.organism_classification, dome, error analysis, ice core, paleoclimate, stratigraphy, sulfate, synchrony, uncertainty analysis, volcanism, Antarctica, Volcano, Talos, lcsh:TD172-193.5, Period (geology), sulphate record, Geology
Abstract: The age scale synchronisation between the Talos Dome and the EPICA Dome C ice cores was carried on through the identification of several common volcanic signatures. This paper describes the rigorous method, using the signature of volcanic sulphate, which was employed for the last 42 kyr of the record. Using this tight stratigraphic link, we transferred the EDC age scale to the Talos Dome ice core, producing a new age scale for the last 12 kyr. We estimated the discrepancies between the modelled TALDICE-1 age scale and the new scale during the studied period, by evaluating the ratio R of the apparent duration of temporal intervals between pairs of isochrones. Except for a very few cases, R ranges between 0.8 and 1.2, corresponding to an uncertainty of up to 20% in the estimate of the time duration in at least one of the two ice cores. At this stage our approach does not allow us to unequivocally identify which of the models is affected by errors, but, taking into account only the historically known volcanic events, we found that discrepancies up to 200 yr appear in the last two millennia in the TALDICE-1 model, while our new age scale shows a much better agreement with the volcanic absolute horizons. Thus, we propose for the Talos Dome ice core a new age scale (covering the whole Holocene) obtained by a direct transfer, via our stratigraphic link, from the EDC modelled age scale by Lemieux-Dudon et al. (2010).
Published: 2012

92. Deglaciation records of 17O-excess in East Antarctica: reliable reconstruction of oceanic normalized relative humidity from coastal sites

Author: Jean Jouzel, Frédéric Prié, Barbara Stenni, Valérie Masson-Delmotte, L. Dümbgen, Amaelle Landais, Renato Winkler, and Harald Sodemann
Subjects: Global and Planetary Change, 010504 meteorology & atmospheric sciences, Stratigraphy, Paleontology, East antarctica, Last Glacial Maximum, 010502 geochemistry & geophysics, Atmospheric sciences, 01 natural sciences, Highly sensitive, symbols.namesake, Ice core, 13. Climate action, Climatology, symbols, Deglaciation, Relative humidity, Lagrangian, Geology, Holocene, 0105 earth and related environmental sciences
Abstract: We measured δ17O and δ18O in two Antarctic ice cores at EPICA Dome C (EDC) and TALDICE (TD), respectively, and computed 17O-excess with respect to VSMOW. The comparison of our 17O-excess data with the previous record obtained at Vostok (Landais et al., 2008a) revealed differences up to 35 ppm in 17O-excess mean level and evolution for the three sites. Our data show that the large increase depicted at Vostok (20 ppm) during the last deglaciation is a regional and not a general pattern in the temporal distribution of 17O-excess in East Antarctica. The EDC data display an increase of 12 ppm, whereas the TD data show no significant variation from the Last Glacial Maximum (LGM) to the Early Holocene (EH). A Lagrangian moisture source diagnostic revealed very different source regions for Vostok and EDC compared to TD. These findings combined with the results of a sensitivity analysis, using a Rayleigh-type isotopic model, suggest that normalized relative humidity (RHn) at the oceanic source region (OSR) is a determining factor for the spatial differences of 17O-excess in East Antarctica. However, 17O-excess in remote sites of continental Antarctica (e.g. Vostok) may be highly sensitive to local effects. Hence, we consider 17O-excess in coastal East Antarctic ice cores (TD) to be more reliable as a proxy for RHn at the OSR.
Published: 2012

93. Peritidal sedimentary depositional facies and carbon isotope variation across K/T boundary carbonates from NW Adriatic platform

Author: Nevio Pugliese, Barbara Stenni, Vinod Chandra Tewari, Tadej Dolenec, Rodolfo Riccamboni, Katica Drobne, TEWARI V., C, Stenni, Barbara, Pugliese, Nevio, Drobne, K, Riccamboni, Rodolfo, and Dolenec, T.
Subjects: biology, stratigraphy, K/T boundary, Karst, Paleontology, Oceanography, biology.organism_classification, Cretaceous, Foraminifera, Waves and shallow water, Settore GEO/08 - Geochimica e Vulcanologia, Isotopes of carbon, Breccia, Iridium anomaly, Sedimentary rock, Sequence stratigraphy, Ecology, Evolution, Behavior and Systematics, Geology, Earth-Surface Processes
Abstract: The K/T boundary in the Karst region (Italy and Slovenia) is well documented in correspondence to shallow water limestones. Its evidence is usually related to palaeontological data (disappearance of Cretaceous taxa and subsequent appearance of Tertiary ones), palaeomagnetism (Ch 29r) iridium anomaly and negative shift of δ 13 C. In Italy, the Padriciano section highlights the K/T boundary included in the basal breccia of a peritidal cycle. Recent investigations brought to light a short well exposed new stratigraphic sequence containing the K/T boundary, 100 m east of Padriciano, as demonstrated by lithological, palaeontological and new isotopic data. The recording of a new peritidal setting denotes stressed environmental conditions. The findings of the biota mostly correspond to the lagoonal limestones of the peritidal cycle. It consists of small opportunistic thin shelled foraminifers, ostracods and gastropods. At Padriciano, the environmental stability occurred after episodesofstrongfreshwaterinfluence.Theintraclasts,oncolitesandstromatoliteshavebeenobservedinthePadricianosection.The broken shell fragments, algae and foraminifera have been found associated with fenestral fabric. These features indicate deposition in a shallow marine (intertidal to supratidal) environment. Algal boundstones and microbial (stromatolitic) laminae, crenulated domal laminae and crenulatedconical laminae havebeen studied in petrographicsections for microstructures. The K/T boundary section has been analysed for the carbon and oxygen isotopic ratios. The δ 13 C values range from �3.62 to �10.01‰ (V-PDB) and the δ 18 O values range from �3.85 to �5.47‰ (V-PDB). This extreme depletion in the δ 13 C record has already been reported from other K/T boundary sections both in the Padriciano area (Italy) and in Slovenia (Dolenja Vas sections) and may be related to global climate change but also to local environmental changes occurring in the NWAdriatic Platform. © 2007 Elsevier B.V. All rights reserved.
Published: 2007

94. Climate dependent contrast in surface mass balance in East Antarctica over the past 216 kyr

Author: Kenji Kawamura, Hideaki Motoyama, Fuyuki Saito, Eric W. Wolff, Shuji Fujita, Ryu Uemura, Valérie Masson-Delmotte, Ayako Abe-Ouchi, Mirko Severi, Frédéric Parrenin, Barbara Stenni, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), and 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)
Subjects: geography, geography.geographical_feature_category, Stable isotope ratio, Atmospheric sciences, Glacier mass balance, Ice core, [SDU]Sciences of the Universe [physics], Settore GEO/08 - Geochimica e Vulcanologia, Climatology, Interglacial, Glacial period, Ice sheet, Air mass, Sea level, Geology
Abstract: Documenting past changes in the East Antarctic surface mass balance is important to improve ice core chronologies and to constrain the ice sheet contribution to global mean sea level. Here we reconstruct the past changes in the ratio of surface mass balance (SMB ratio) between the EPICA Dome C (EDC) and Dome Fuji (DF) East Antarctica ice core sites, based on a precise volcanic synchronisation of the two ice cores and on corrections for the vertical thinning of layers. During the past 216 000 years, this SMB ratio, denoted SMBEDC/SMBDF, varied between 0.7 and 1.1, decreasing during cold periods and increasing during warm periods. While past climatic changes have been depicted as homogeneous along the East Antarctic Plateau, our results reveal larger amplitudes of changes in SMB at EDC compared to DF, consistent with previous results showing larger amplitudes of changes in water stable isotopes and estimated surface temperature at EDC compared to DF. Within interglacial periods and during the last glacial inception (Marine Isotope Stages, MIS-5c and MIS-5d), the SMB ratio deviates by up to 30% from what is expected based on differences in water stable isotope records. Moreover, the SMB ratio is constant throughout the late parts of the current and last interglacial periods, despite contrasting isotopic trends. These SMB ratio changes not closely related to isotopic changes are one of the possible causes of the observed gaps between the ice core chronologies at DF and EDC. Such changes in SMB ratio may have been caused by (i) climatic processes related to changes in air mass trajectories and local climate, (ii) glaciological processes associated with relative elevation changes, or (iii) a combination of climatic and glaciological processes, such as the interaction between changes in accumulation and in the position of the domes. Our inferred SMB ratio history has important implications for ice sheet modeling (for which SMB is a boundary condition) or atmospheric modeling (our inferred SMB ratio could serve as a test).
Published: 2015

95. Can we retrieve a clear paleoclimatic signal from the deeper part of the EPICA Dome C ice core?

Author: Jean-Robert Petit, Barbara Delmonte, Roland Souchez, Bernhard Bereiter, V. Lipenkov, J. M. Barnola, Anna Wegner, Sigfus J Johnsen, Eric W. Wolff, Geoffroy Durand, Adrian Schilt, Amaelle Landais, Dorthe Dahl-Jensen, L. Loulergue, M. de Angelis, Roberto Udisti, Jean Jouzel, K. Pol, Barbara Stenni, Hubertus Fischer, Geneviève C Littot, Margareta Hansson, Renato Spahni, Gabrielle Dreyfus, Valerie Masson-Delmotte, Denis Samyn, Jean-Louis Tison, Reginald Lorrain, and Matthias Bigler
Subjects: geography, geography.geographical_feature_category, 010504 meteorology & atmospheric sciences, Ice stream, 010502 geochemistry & geophysics, 01 natural sciences, Ice wedge, Ice core, Sea ice growth processes, 13. Climate action, Stamukha, Pancake ice, Ice divide, Ice sheet, Petrology, Geomorphology, Geology, 0105 earth and related environmental sciences
Abstract: An important share of paleoclimatic information is buried within the lowermost layers of deep ice cores. Because improving our records further back in time is one of the main challenges in the near future, it is essential to judge how deep these records remain unaltered, since the proximity of the bedrock is likely to interfere both with the recorded temporal sequence and the ice properties. In this paper, we present a multiparametric study (δD-δ18Oice, δ18Oatm, total air content, CO2, CH4, N2O, dust, high resolution chemistry, ice texture) of the bottom 60 m of the EPICA Dome C ice core from central Antarctica. These bottom layers have been subdivided in two sections: the lower 12 m showing visible solid inclusions (basal ice) and the 48 m above which we refer to as "deep ice". Some of the data are consistent with a pristine paleoclimatic signal, others show clear anomalies. It is demonstrated that neither large scale bottom refreezing of subglacial water, nor mixing (be it internal or with a local basal end-term from a previous/initial ice sheet configuration) can explain the observed bottom ice properties. We focus on the high-resolution chemical profiles and on the available remote sensing data on the subglacial topography of the site to propose a mechanism by which relative stretching of the bottom ice sheet layers is made possible, due to the progressively confining effect of subglacial valley sides. This stress field change, combined with bottom ice temperature close to the pressure melting point, induces accelerated migration recrystallization, which results in spatial chemical sorting of the impurities, depending on their state (dissolved vs. solid) and if they are involved or not in salt formation. This chemical sorting effect is responsible for the progressive build-up of the visible solid aggregates that therefore mainly originate "from within", and not from incorporation processes of allochtone material at the ice–bedrock interface. We also discuss how the proposed mechanism is compatible with the other variables described. We conclude that the paleoclimatic signal is only marginally affected in terms of global ice properties at the bottom of EPICA Dome C, but that the time scale has been considerably distorted by mechanical stretching of MIS20 due to the increasing influence of the subglacial topography, a process that might have started well above the bottom ice.
Published: 2015

96. Retrieving the paleoclimatic signal from the deeper part of the EPICA Dome C ice core

Author: Margareta Hansson, Dorthe Dahl-Jensen, Amaelle Landais, Valérie Masson-Delmotte, G. Dreyfus, J. M. Barnola, Denis Samyn, Geoffroy Durand, Barbara Stenni, K. Pol, Adrian Schilt, Geneviève C Littot, M. de Angelis, Jean-Louis Tison, Eric W. Wolff, Roberto Udisti, Barbara Delmonte, L. Loulergue, Vladimir Ya. Lipenkov, Hubertus Fischer, Jean Jouzel, Sigfus J Johnsen, Renato Spahni, Jean-Robert Petit, Bernhard Bereiter, Anna Wegner, Reginald Lorrain, Matthias Bigler, Roland Souchez, Département des Sciences de la Terre et de l'Environnement, Université Libre de Bruxelles [Bruxelles] (ULB), Laboratoire de glaciologie et géophysique de l'environnement (LGGE), 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), British Antarctic Survey (BAS), Natural Environment Research Council (NERC), Climate and Environmental Physics [Bern] (CEP), Physikalisches Institut [Bern], Universität Bern [Bern]-Universität Bern [Bern], University of Stockolm, Chemistry Department, University of Florence (UNIFI), Department of Bentho-pelagic processes, Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), 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), University Ca' Foscari, University of Ca’ Foscari [Venice, Italy], Niels Bohr Institute [Copenhagen] (NBI), Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU), Arctic and Antarctic Research Institute (AARI), Russian Federal Service for Hydrometeorology and Environmental Monitoring (Roshydromet), Dipartimento di Scienze dell'Ambiente e del Territorio (DISAT), Università degli studi di Milano [Milano], Oak Ridge Institute for Science and Education Climate Change Policy and Technology Fellow with the US Department of Energy Office of Policy and International Affairs, Nagaoka University of Technology, Wolff, Eric [0000-0002-5914-8531], Apollo - University of Cambridge Repository, Université libre de Bruxelles (ULB), 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), Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), 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), Dipartimento di Scienze Ambientali, Informatica e Statistica, Università degli Studi di Milano [Milano] (UNIMI), 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), Universität Bern [Bern] (UNIBE)-Universität Bern [Bern] (UNIBE), Università degli Studi di Firenze = University of Florence (UniFI), 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), University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH), Università degli Studi di Milano = University of Milan (UNIMI), Tison, J, de Angelis, M, Littot, G, Wolff, E, Fischer, H, Hansson, M, Bigler, M, Udisti, R, Wegner, A, Jouzel, J, Stenni, B, Johnsen, S, Masson Delmotte, V, Landais, A, Lipenkov, V, Loulergue, L, Barnola, J, Petit, J, Delmonte, B, Dreyfus, G, Dahl Jensen, D, Durand, G, Bereiter, B, Schilt, A, Spahni, R, Pol, K, Lorrain, R, Souchez, R, and Samyn, D
Subjects: Water Science and Technology, Earth-Surface Processes, 010504 meteorology & atmospheric sciences, 530 Physics, SUBGLACIAL LAKE VOSTOK, PAST 800,000 YEARS, BASAL ICE, CENTRAL GREENLAND, EAST ANTARCTICA, CLIMATE VARIABILITY, MILLENNIAL-SCALE, ANOMALOUS DIFFUSION, DEBRIS ENTRAINMENT, GAS-COMPOSITION, DEBRIS ENTRAINMENT, sub-01, Ice stream, CENTRAL GREENLAND, 3705 Geology, Antarctic sea ice, 010502 geochemistry & geophysics, 01 natural sciences, Ice shelf, 000 YEARS, ice cores, Antarctica, Paleoclimate, BASAL ICE, Meteorology and Climatology, Ice core, CLIMATE VARIABILITY, Sea ice, Ice divide, Petrology, Geomorphology, lcsh:Environmental sciences, ANOMALOUS DIFFUSION, 0105 earth and related environmental sciences, lcsh:GE1-350, geography, SUBGLACIAL LAKE VOSTOK, geography.geographical_feature_category, EAST ANTARCTICA, Géologie et minéralogie, European Project for Ice Coring in Antarctica, lcsh:QE1-996.5, PAST 800, 37 Earth Sciences, MILLENNIAL-SCALE, 3709 Physical Geography and Environmental Geoscience, GAS-COMPOSITION, lcsh:Geology, Settore GEO/08 - Geochimica e Vulcanologia, 13. Climate action, [SDE]Environmental Sciences, théorie et applications [Econométrie et méthodes statistiques], Ice sheet, Geology
Abstract: An important share of paleoclimatic information is buried within the lowermost layers of deep ice cores. Because improving our records further back in time is one of the main challenges in the near future, it is essential to judge how deep these records remain unaltered, since the proximity of the bedrock is likely to interfere both with the recorded temporal sequence and the ice properties. In this paper, we present a multiparametric study (δD-δ18Oice, δ18Oatm, total air content, CO2, CH4, N2O, dust, high-resolution chemistry, ice texture) of the bottom 60 m of the EPICA (European Project for Ice Coring in Antarctica) Dome C ice core from central Antarctica. These bottom layers were subdivided into two distinct facies: the lower 12 m showing visible solid inclusions (basal dispersed ice facies) and the upper 48 m, which we will refer to as the "basal clean ice facies". Some of the data are consistent with a pristine paleoclimatic signal, others show clear anomalies. It is demonstrated that neither large-scale bottom refreezing of subglacial water, nor mixing (be it internal or with a local basal end term from a previous/initial ice sheet configuration) can explain the observed bottom-ice properties. We focus on the high-resolution chemical profiles and on the available remote sensing data on the subglacial topography of the site to propose a mechanism by which relative stretching of the bottom-ice sheet layers is made possible, due to the progressively confining effect of subglacial valley sides. This stress field change, combined with bottom-ice temperature close to the pressure melting point, induces accelerated migration recrystallization, which results in spatial chemical sorting of the impurities, depending on their state (dissolved vs. solid) and if they are involved or not in salt formation. This chemical sorting effect is responsible for the progressive build-up of the visible solid aggregates that therefore mainly originate "from within", and not from incorporation processes of debris from the ice sheet's substrate. We further discuss how the proposed mechanism is compatible with the other ice properties described. We conclude that the paleoclimatic signal is only marginally affected in terms of global ice properties at the bottom of EPICA Dome C, but that the timescale was considerably distorted by mechanical stretching of MIS20 due to the increasing influence of the subglacial topography, a process that might have started well above the bottom ice. A clear paleoclimatic signal can therefore not be inferred from the deeper part of the EPICA Dome C ice core. Our work suggests that the existence of a flat monotonic ice-bedrock interface, extending for several times the ice thickness, would be a crucial factor in choosing a future "oldest ice" drilling location in Antarctica., SCOPUS: ar.j, info:eu-repo/semantics/published
Published: 2015

97. A review of the bipolar see-saw from synchronized and high resolution ice core water stable isotope records from Greenland and East Antarctica

Author: Didier M. Roche, Vasileios Gkinis, Fabrice Lambert, Lucie Bazin, Olivier Arzel, Bo Møllesøe Vinther, Valérie Masson-Delmotte, Enricomaria Selmo, Myriam Guillevic, Barbara Stenni, Trevor Popp, Jean Jouzel, Amaelle Landais, 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), Departments of Mathematics and Geosciences, Environmental and Marine Sciences, University of Trieste, Italy, Department of Environmental Sciences, Informatics and Statistics [Venezia], University of Ca’ Foscari [Venice, Italy], Department of Chemistry, Life Sciences and Environmental Sustainability [Parma], University of Parma = Università degli studi di Parma [Parme, Italie], Modélisation du climat (CLIM), Vrije Universiteit Amsterdam [Amsterdam] (VU), Center for Climate and Resilience Research, Universidad de Chile = University of Chile [Santiago] (UCHILE), Centre for Ice and Climate [Copenhagen], Niels Bohr Institute [Copenhagen] (NBI), Faculty of Science [Copenhagen], 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), Laboratoire de physique des océans (LPO), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-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)-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, Università degli studi di Parma = University of Parma (UNIPR), 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), Earth and Climate, and Amsterdam Global Change Institute
Subjects: Archeology, 010504 meteorology & atmospheric sciences, 010502 geochemistry & geophysics, Dansgaard Oeschger events, 01 natural sciences, Ice cap climate, Ice core, Glacial earthquake, Cryosphere, Bipolar seesaw, Ice cores, Water isotopes, Glacial period, SDG 14 - Life Below Water, Ecology, Evolution, Behavior and Systematics, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, 0105 earth and related environmental sciences, Global and Planetary Change, geography, geography.geographical_feature_category, European Project for Ice Coring in Antarctica, Geology, Ice-sheet model, Settore GEO/08 - Geochimica e Vulcanologia, 13. Climate action, Climatology, Ice sheet
Abstract: International audience; Numerous ice core records are now available that cover the Last Glacial cycle both in Greenland and in Antarctica. Recent developments in coherent ice core chronologies now enable us to depict with a precision of a few centuries the relationship between climate records in Greenland and Antarctica over the millennial scale variability of the Last Glacial period. Stacks of Greenland and Antarctic water isotopic records nicely illustrate a seesaw pattern with the abrupt warming in Greenland being concomitant with the beginning of the cooling in Antarctica at the Antarctic Isotopic Maximum (AIM). In addition, from the precise estimate of chronological error bars and additional high resolution measurements performed on the EDC and TALDICE ice cores, we show that the seesaw pattern does not explain the regional variability in Antarctic records with clear two step structures occurring during the warming phase of AIM 8 and 12. Our Antarctic high resolution data also suggest possible teleconnections between changes in low latitude atmospheric circulation and Antarctic without any Greenland temperature fingerprint.
Published: 2015

98. Past temperature reconstructions from deep ice cores: relevance for future climate change

Author: Amaelle Landais, Sigfus J Johnsen, Barbara Stenni, Pascale Braconnot, Jean Jouzel, Frédéric Parrenin, Dominique Raynaud, Gabrielle Dreyfus, Masa Kageyama, Julius Nouet, Valérie Masson-Delmotte, E. Tuenter, Marie-France Loutre, 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), Modelling the Earth Response to Multiple Anthropogenic Interactions and Dynamics (MERMAID), Niels Bohr Institute [Copenhagen] (NBI), Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU), Modélisation du climat (CLIM), Institut d'Astronomie et de Géophysique Georges Lemaître (UCL-ASTR), Université Catholique de Louvain = Catholic University of Louvain (UCL), Laboratoire de glaciologie et géophysique de l'environnement (LGGE), 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), Department of Geological, Environmental and Marine Sciences [Trieste], Università degli studi di Trieste, Department of Earth Sciences [Utrecht], Utrecht University [Utrecht], 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), University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH), 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), Università degli studi di Trieste = University of Trieste, 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), Institute of Earth Sciences, Hebrew University, Université Catholique de Louvain (UCL), 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), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut national des sciences de l'Univers (INSU - CNRS)-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)-Université Paris-Saclay-Institut national des sciences de l'Univers (INSU - CNRS)-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)-Université Paris-Saclay-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Observatoire des Sciences de l'Univers de Grenoble [1985-2015] (OSUG [1985-2015]), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology [2007-2019] (Grenoble INP [2007-2019])-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)-Institut polytechnique de Grenoble - Grenoble Institute of Technology [2007-2019] (Grenoble INP [2007-2019])-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), Dipartimento di Scienze Geologiche [Trieste], Royal Netherlands Meteorological Institute (KNMI), Observatoire des Sciences de l'Univers de Grenoble [1985-2015] (OSUG [1985-2015]), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology [2007-2019] (Grenoble INP [2007-2019])-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 [2007-2019] (Grenoble INP [2007-2019])-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), Masson Delmotte, V., Dreyfus, G., Braconnot, P., Johnsen, S., Jouzel, J., Kageyama, M., Landais, A., Loutre, M. F., Nouet, J., Parrenin, F., Raynaud, D., Stenni, Barbara, and Teunter, E.
Subjects: 010506 paleontology, 010504 meteorology & atmospheric sciences, Stratigraphy, lcsh:Environmental protection, Climate change, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, polar ice core, climate model, 010502 geochemistry & geophysics, 01 natural sciences, Past temperature reconstructions, Ice core, lcsh:Environmental pollution, climate models, Past temperature reconstruction, lcsh:TD169-171.8, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Polar climate, ComputingMilieux_MISCELLANEOUS, lcsh:Environmental sciences, 0105 earth and related environmental sciences, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, lcsh:GE1-350, Global and Planetary Change, geography, geography.geographical_feature_category, polar ice cores, future climate changes, Paleontology, Ice-sheet model, Settore GEO/08 - Geochimica e Vulcanologia, 13. Climate action, Climatology, Interglacial, lcsh:TD172-193.5, Abrupt climate change, Climate state, Ice sheet, Geology
Abstract: International audience; Ice cores provide unique archives of past climate and environmental changes based only on physical processes. Quantitative temperature reconstructions are essential for the comparison between ice core records and climate models. We give an overview of the methods that have been developed to reconstruct past local temperatures from deep ice cores and highlight several points that are relevant for future climate change. We first analyse the long term fluctuations of temperature as depicted in the long Antarctic record from EPICA Dome C. The long term imprint of obliquity changes in the EPICA Dome C record is highlighted and compared to simulations conducted with the ECBILT-CLIO intermediate complexity climate model. We discuss the comparison between the current interglacial period and the long interglacial corresponding to marine isotopic stage 11, ~400 kyr BP. Previous studies had focused on the role of precession and the thresholds required to induce glacial inceptions. We suggest that, due to the low eccentricity configuration of MIS 11 and the Holocene, the effect of precession on the incoming solar radiation is damped and that changes in obliquity must be taken into account. The EPICA Dome C alignment of terminations I and VI published in 2004 corresponds to a phasing of the obliquity signals. A conjunction of low obliquity and minimum northern hemisphere summer insolation is not found in the next tens of thousand years, supporting the idea of an unusually long interglacial ahead. As a second point relevant for future climate change, we discuss the magnitude and rate of change of past temperatures reconstructed from Greenland (NorthGRIP) and Antarctic (Dome C) ice cores. Past episodes of temperatures above the present-day values by up to 5°C are recorded at both locations during the penultimate interglacial period. The rate of polar warming simulated by coupled climate models forced by a CO2 increase of 1% per year is compared to ice-core-based temperature reconstructions. In Antarctica, the CO2-induced warming lies clearly beyond the natural rhythm of temperature fluctuations. In Greenland, the CO2-induced warming is as fast or faster than the most rapid temperature shifts of the last ice age. The magnitude of polar temperature change in response to a quadrupling of atmospheric CO2 is comparable to the magnitude of the polar temperature change from the Last Glacial Maximum to present-day. When forced by prescribed changes in ice sheet reconstructions and CO2 changes, climate models systematically underestimate the glacial-interglacial polar temperature change.
Published: 2006

99. Common millennial-scale variability of Antarctic and Southern Ocean temperatures during the past 5000 years reconstructed from the EPICA Dome C ice core

Author: Valérie Masson-Delmotte, Jean Jouzel, Barbara Stenni, 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), Department of Geological, Environmental and Marine Sciences [Trieste], Università degli studi di Trieste, Masson Delmotte, V., Stenni, Barbara, Jouzel, J., 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), and Università degli studi di Trieste = University of Trieste
Subjects: 010506 paleontology, Archeology, Millennial-scale variability, climatic variations, ice core, EPICA, Southern Ocean, Dome C, isotopic modelling, Climatic Optimum, Holocene, Antarctica, 010504 meteorology & atmospheric sciences, Dome, climatic variation, Holocene climatic optimum, 01 natural sciences, Ice core, Paleoclimatology, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Earth-Surface Processes, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Global and Planetary Change, Ecology, Stable isotope ratio, European Project for Ice Coring in Antarctica, Paleontology, Sea surface temperature, Oceanography, Settore GEO/08 - Geochimica e Vulcanologia, 13. Climate action, Geology
Abstract: Measurements of the two water stable isotopes (dD and d18O) along EPICA (European Project for Ice Coring in Antarctica) Dome C ice core are combined with simple isotopic modelling (distillation models) to reconstruct the variability of both the site temperature (East Antarctica) and the moisture source temperature (nowadays probably the subantarctic Indian Ocean). We discuss the difference between the reconstructed site and source temperature pro” les with respect to the initial isotopic data. We show that (i) the early-Holocene optimum appears” rst in Antarctica and 800 years later in the Southern Ocean, and (ii) during the last 5000 years, the site and source temperatures co-vary at the centennial timescale. An 833-year periodicity is observed only on deuterium and site temperature and therefore probably of local origin.
Published: 2004

100. Growth processes of an inland Antarctic ice wedge, Mesa Range, northern Victoria Land

Author: Stefano Polesello, Rossana Raffi, Barbara Stenni, O. Flora, and Marina Camusso
Subjects: 010506 paleontology, geography, geography.geographical_feature_category, 010504 meteorology & atmospheric sciences, δ18O, Glacier, chemical concentration, ice crystal, ice wedge, stable water isotopes, tritium activity, Block (meteorology), 01 natural sciences, Wedge (geometry), Regolith, Ice wedge, Altitude, Volcano, Geomorphology, Geology, 0105 earth and related environmental sciences, Earth-Surface Processes
Abstract: During the XVI Italian Antarctic Expedition (2000-2001) the geomorphologic survey of permafrost-related polygons has been carried out in the northern sector of Mesa Range - Pain Mesa - located in the upper part of Rennick Glacier. An ice wedge was found in a volcanic regolith at an elevation of about 2200 m a.s.l.. This altitude is below the trimline that in this sector of Mesa Range is at 2380 m a.s.l.. Samples of ice were taken using a 14 mm internal diameter ice screw that was inserted into the ice wedge in vertical sequences. A co-isotopic study was performed, measuring both oxygen (?18O) and hydrogen (?D) isotope compositions. Tritium activity measurements were carried out on the same samples as well as chemical determinations of both major cations and anions. The ?18O and ?D obtained showed a strong divergence from the expected snowfalls occurring at this elevation, with extremely negative d excess values. Melting-refreezing and/or sublimation processes were taken into account to define the origin of the ice forming the wedge. The tritium data obtained suggest that the growth process of the ice wedge might be active still today. High values of non-sea salt sulphate concentrations, obtained for all samples, showed a strong contribution from a terrestrial source for sulphate which is probably associated with calcium.
Published: 2004

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