68 results on '"Aurélien Quiquet"'
Search Results
2. Improving biome and climate modelling for a set of past climate conditions: evaluating bias correction using the CDF-t approach
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Anhelina Zapolska, Mathieu Vrac, Aurélien Quiquet, Thomas Extier, Frank Arthur, Hans Renssen, and Didier M Roche
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bias correction ,palaeoclimate modelling ,climate downscaling ,model-data comparison ,Meteorology. Climatology ,QC851-999 ,Environmental sciences ,GE1-350 - Abstract
Climate model simulations are inherently biased. It is a notably difficult problem when dealing with climate impact assessments and model-data integration. This is especially true when looking at derived quantities such as biomes, where not only climate but also vegetation dynamics biases come into play. To overcome such difficulties, we evaluate the performance of an existing methodology to correct climate model outputs, applied here for the first time to long past climate conditions. The proposed methodology relies on the ‘Cumulative Distribution Function-transform’ (CDF-t) technique, which allows to account for climate change within the bias-correction procedure. The results are evaluated in two independent ways: (i) using forward modelling, so that model results are directly comparable to reconstructed vegetation distribution; (ii) using climatic reconstructions based on an inverse modelling approach. The modelling is performed using the intermediate complexity model iLOVECLIM in the standard global and interactively downscaled over the Europe version. The combined effects of dynamical downscaling and bias correction resulted in significantly stronger agreement between the simulated results and pollen-based biome reconstructions (BIOME6000) for the pre-industrial (0.18 versus 0.44) and mid-Holocene (MH) (0.31 versus 0.40). Higher correlation is also observed between statistically modelled global gridded potential natural distribution and modelled biomes (0.36 versus 0.41). Similarly, we find higher correlation between the reconstructed and the modelled temperatures for the MH (0.02 versus 0.21). No significant difference is found for the Last Glacial Maximum when using temperature reconstructions, due to the low number of data points available. Our findings show that the application of the CDF-t method on simulated climate variables enables us to simulate palaeoclimate and vegetation distribution in better agreement with independent reconstructions.
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- 2023
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3. Antarctic ice sheet response to sudden and sustained ice-shelf collapse (ABUMIP)
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Sainan Sun, Frank Pattyn, Erika G. Simon, Torsten Albrecht, Stephen Cornford, Reinhard Calov, Christophe Dumas, Fabien Gillet-Chaulet, Heiko Goelzer, Nicholas R. Golledge, Ralf Greve, Matthew J. Hoffman, Angelika Humbert, Elise Kazmierczak, Thomas Kleiner, Gunter R. Leguy, William H. Lipscomb, Daniel Martin, Mathieu Morlighem, Sophie Nowicki, David Pollard, Stephen Price, Aurélien Quiquet, Hélène Seroussi, Tanja Schlemm, Johannes Sutter, Roderik S. W. van de Wal, Ricarda Winkelmann, and Tong Zhang
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Antarctic glaciology ,ice-sheet modelling ,ice shelves ,Environmental sciences ,GE1-350 ,Meteorology. Climatology ,QC851-999 - Abstract
Antarctica's ice shelves modulate the grounded ice flow, and weakening of ice shelves due to climate forcing will decrease their ‘buttressing’ effect, causing a response in the grounded ice. While the processes governing ice-shelf weakening are complex, uncertainties in the response of the grounded ice sheet are also difficult to assess. The Antarctic BUttressing Model Intercomparison Project (ABUMIP) compares ice-sheet model responses to decrease in buttressing by investigating the ‘end-member’ scenario of total and sustained loss of ice shelves. Although unrealistic, this scenario enables gauging the sensitivity of an ensemble of 15 ice-sheet models to a total loss of buttressing, hence exhibiting the full potential of marine ice-sheet instability. All models predict that this scenario leads to multi-metre (1–12 m) sea-level rise over 500 years from present day. West Antarctic ice sheet collapse alone leads to a 1.91–5.08 m sea-level rise due to the marine ice-sheet instability. Mass loss rates are a strong function of the sliding/friction law, with plastic laws cause a further destabilization of the Aurora and Wilkes Subglacial Basins, East Antarctica. Improvements to marine ice-sheet models have greatly reduced variability between modelled ice-sheet responses to extreme ice-shelf loss, e.g. compared to the SeaRISE assessments.
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- 2020
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4. Author Correction: Wilkes subglacial basin ice sheet response to Southern Ocean warming during late Pleistocene interglacials
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Ilaria Crotti, Aurélien Quiquet, Amaelle Landais, Barbara Stenni, David J. Wilson, Mirko Severi, Robert Mulvaney, Frank Wilhelms, Carlo Barbante, and Massimo Frezzotti
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Science - Published
- 2022
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5. Ice flux evolution in fast flowing areas of the Greenland ice sheet over the 20th and 21st centuries
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DANIELE PEANO, FLORENCE COLLEONI, AURÉLIEN QUIQUET, and SIMONA MASINA
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climate change ,ice-sheet mass balance ,ice-sheet modelling ,ice streams ,Environmental sciences ,GE1-350 ,Meteorology. Climatology ,QC851-999 - Abstract
This study investigates the evolution of Greenland ice sheet flux focusing on five of the main fast flowing regions (Petermann glacier, North East Greenland Ice Stream, Kangerdlugssuaq glacier, Helheim glacier and Jakobshavn glacier) in response to 20th and 21st century climate change. A hybrid (shallow ice and shallow shelf) ice-sheet model (ISM) is forced with the combined outputs of a set of seven CMIP5 models and the regional climate model MAR. The ISM simulates the present-day ice velocity pattern, topography and surface mass balance (SMB) in good agreement with observations. Except for the Kangerdlugssuaq glacier, over the 21st century all the fast-flowing areas have exhibited a decrease in ice flux as a result of a negative SMB rather than dynamical changes. Only the fronts of Kangerdlugssuaq and Helheim glaciers have shown an interannual variability driven by dynamical rather than climate changes. Finally, the results predict a substantial inland ice margin retreat by the end of the 21st century, especially along the northern coasts.
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- 2017
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6. Retrieval of the Absorption Coefficient of L-Band Radiation in Antarctica From SMOS Observations
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Olivier Passalacqua, Ghislain Picard, Catherine Ritz, Marion Leduc-Leballeur, Aurélien Quiquet, Fanny Larue, and Giovanni Macelloni
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passive microwave ,Band L ,SMOS ,Antarctica ,brightness temperature ,emissivity ,permittivity ,absorption coefficient ,Science - Abstract
Microwave emissions at the L-band (1⁻2 GHz) in Antarctica are characterized by a significant contribution of ice layers at great depth, from hundreds to a thousand meters. Brightness temperatures, thus, could provide the internal temperature of the ice sheet. However, there are two difficulties to overcome in developing an accurate retrieval algorithm. First, it is difficult to know precisely from which depths waves are emanating because the ice-absorption coefficient is uncertain at the L-band, despite several formulations proposed in the literature over the past few decades. Second, emissivity potentially varies in Antarctica due to remnant scattering in firn (or ice), even at the Brewster angle, and despite the low frequency, limiting the accuracy of the estimate of the physical temperature. Here, we present a retrieval method able to disentangle the absorption and emissivity effects from brightness temperature over the whole continent. We exploit the fact that scattering and absorption are controlled by different physical parameters and phenomena that can be considered as statistically independent. This independence provides a constraint to the retrieval method, that is then well-conditioned and solvable. Our results show that (1) the retrieved absorption agrees with the permittivity model proposed by Mätzler et al. (2006), and (2) emissivity shows significant variations, up to 6% over the continent, which are correlated with wind speed and accumulation patterns. A possible cause of this latter point is density heterogeneity and sastrugi buried in the firn. These two results are an important step forward for the accurate retrieval of internal temperature using low-frequency microwave radiometers.
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- 2018
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7. ISMIP6 Antarctica: a multi-model ensemble of the Antarctic ice sheet evolution over the 21st century
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Hélène Seroussi, Sophie Nowicki, Antony J. Payne, Heiko Goelzer, William H. Lipscomb, Ayako Abe-Ouchi, Cécile Agosta, Torsten Albrecht, Xylar Asay-Davis, Alice Barthel, Reinhard Calov, Richard Cullather, Christophe Dumas, Benjamin K. Galton-Fenzi, Rupert Gladstone, Nicholas R. Golledge, Jonathan M. Gregory, Ralf Greve, Tore Hattermann, Matthew J. Hoffman, Angelika Humbert, Philippe Huybrechts, Nicolas C. Jourdain, Thomas Kleiner, Eric Larour, Gunter R. Leguy, Daniel P. Lowry, Chistopher M. Little, Mathieu Morlighem, Frank Pattyn, Tyler Pelle, Stephen F. Price, Aurélien Quiquet, Ronja Reese, Nicole-Jeanne Schlegel, Andrew Shepherd, Erika Simon, Robin S. Smith, Fiammetta Straneo, Sainan Sun, Luke D. Trusel, Jonas Van Breedam, Roderik S. W. van de Wal, Ricarda Winkelmann, Chen Zhao, Tong Zhang, and Thomas Zwinger
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- 2020
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8. Simulations of the Holocene climate in Europe using an interactive downscaling within the iLOVECLIM model (version 1.1)
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Frank Arthur, Didier M. Roche, Ralph Fyfe, Aurélien Quiquet, Hans Renssen, Earth Sciences, University of South-Eastern Norway (USN), Vrije Universiteit Amsterdam [Amsterdam] (VU), 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), Modélisation du climat (CLIM), 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), School of Geography, Earth and Environmental Sciences [Plymouth] (SoGEES), and Plymouth University
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[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere ,Global and Planetary Change ,Stratigraphy ,SDG 13 - Climate Action ,Paleontology ,[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment - Abstract
This study presents the application of an interactive downscaling in Europe using iLOVECLIM (a model of intermediate complexity), increasing its atmospheric resolution from 5.56 to 0.25∘ kilometric. A transient simulation using the appropriate climate forcings for the entire Holocene (11.5–0 ka BP) was done for both the standard version of the model and with an interactive downscaling applied. Our results show that simulations from downscaling present spatial variability that agrees better with proxy-based reconstructions and other climate models as compared to the standard model. The downscaling scheme simulates much higher (by at least a factor of 2) precipitation maxima and provides detailed information in mountainous regions. We focus on examples from the Scandes mountains, the Alps, the Scottish Highlands, and the Mediterranean. The higher spatial resolution of the downscaling provides a more realistic overview of the topography and gives local climate information, such as precipitation and temperature gradient, that is important for paleoclimate studies. With downscaling, we simulate similar trends and spatial patterns of the precipitation changes reconstructed by other proxy studies (for example in the Alps) as compared to the standard version. Our downscaling tool is numerically cheap, implying that our model can perform kilometric, multi-millennial simulations and is suitable for future studies.
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- 2023
9. The PMIP4 Last Glacial Maximum experiments: preliminary results and comparison with the PMIP3 simulations
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Masa Kageyama, Sandy P. Harrison, Marie-L. Kapsch, Marcus Lofverstrom, Juan M. Lora, Uwe Mikolajewicz, Sam Sherriff-Tadano, Tristan Vadsaria, Ayako Abe-Ouchi, Nathaelle Bouttes, Deepak Chandan, Lauren J. Gregoire, Ruza F. Ivanovic, Kenji Izumi, Allegra N. LeGrande, Fanny Lhardy, Gerrit Lohmann, Polina A. Morozova, Rumi Ohgaito, André Paul, W. Richard Peltier, Christopher J. Poulsen, Aurélien Quiquet, Didier M. Roche, Xiaoxu Shi, Jessica E. Tierney, Paul J. Valdes, Evgeny Volodin, and Jiang Zhu
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Meteorology And Climatology - Abstract
The Last Glacial Maximum (LGM, ∼ 21 000 years ago) has been a major focus for evaluating how well state-of-the-art climate models simulate climate changes as large as those expected in the future using paleoclimate reconstructions. A new generation of climate models has been used to generate LGM simulations as part of the Paleoclimate Modelling Intercomparison Project (PMIP) contribution to the Coupled Model Intercomparison Project (CMIP). Here, we provide a preliminary analysis and evaluation of the results of these LGM experiments (PMIP4, most of which are PMIP4-CMIP6) and compare them with the previous generation of simulations (PMIP3, most of which are PMIP3-CMIP5). We show that the global averages of the PMIP4 simulations span a larger range in terms of mean annual surface air temperature and mean annual precipitation compared to the PMIP3-CMIP5 simulations, with some PMIP4 simulations reaching a globally colder and drier state. However, the multi-model global cooling average is similar for the PMIP4 and PMIP3 ensembles, while the multi-model PMIP4 mean annual precipitation average is drier than the PMIP3 one. There are important differences in both atmospheric and oceanic circulations between the two sets of experiments, with the northern and southern jet streams being more poleward and the changes in the Atlantic Meridional Overturning Circulation being less pronounced in the PMIP4-CMIP6 simulations than in the PMIP3-CMIP5 simulations. Changes in simulated precipitation patterns are influenced by both temperature and circulation changes. Differences in simulated climate between individual models remain large. Therefore, although there are differences in the average behaviour across the two ensembles, the new simulation results are not fundamentally different from the PMIP3-CMIP5 results. Evaluation of large-scale climate features, such as land–sea contrast and polar amplification, confirms that the models capture these well and within the uncertainty of the paleoclimate reconstructions. Nevertheless, regional climate changes are less well simulated: the models underestimate extratropical cooling, particularly in winter, and precipitation changes. These results point to the utility of using paleoclimate simulations to understand the mechanisms of climate change and evaluate model performance.
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- 2021
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10. Projected land ice contributions to twenty-first-century sea level rise
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Tamsin L. Edwards, Sophie Nowicki, Ben Marzeion, Regine Hock, Heiko Goelzer, Hélène Seroussi, Nicolas C. Jourdain, Donald A. Slater, Fiona E. Turner, Christopher J. Smith, Christine M. McKenna, Erika Simon, Ayako Abe-Ouchi, Jonathan M Gregory, Eric Larour, William H. Lipscomb, Antony J. Payne, Andrew Shepherd, Cécile Agosta, Patrick Alexander, Torsten Albrecht, Brian Anderson, Xylar Asay-Davis, Andreas Aschwanden, Alice Barthel, Andrew Bliss, Reinhard Calov, Christopher Chambers, Nicolas Champollion, Youngmin Choi, Richard Cullather, Joshua Cuzzone, Christophe Dumas, Denis Felikson, Xavier Fettweis, Koji Fujita, Benjamin K. Galton-Fenzi, Rupert Gladstone, Nicolas R. Gollege, Ralf Greve, Tore Hattermann, Matthew J. Hoffman, Angelika Humbert, Matthias Huss, Philippe Huybrechts, Walter Immerzeel, Thomas Kleiner, Philip Kraaijenbrink, Sebastien Le clec'h, Victoria Lee, Gunter R. Leguy, Christopher M. Little, Daniel P. Lowry, Jan-Hendrik Malles, Daniel F. Martin, Fabien Maussion, Mathieu Morlighem, James F. O’Neill, Isabel Nias, Frank Pattyn, Tyler Pelle, Stephen F Price, Aurélien Quiquet, Valentina Radić, Ronja Reese, David R. Rounce, Martin Rückamp, Akiko Sakai, Courtney Shafer, Nicole-Jeanne Schlegel, Sarah Shannon, Robin S. Smith, Fiammetta Straneo, Sainan Sun, Lev Tarasov, Luke D. Trusel, Jonas Van Breedam, Roderik van de Wal, Michiel van den Broeke, Ricarda Winkelmann, Harry Zekollari, Chen Zhao, Tong Zhang, and Thomas Zwinger
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Earth Resources And Remote Sensing ,Numerical Analysis - Abstract
The land ice contribution to global mean sea level rise has not yet been predicted1 using ice sheet and glacier models for the latest set of socio-economic scenarios, nor using coordinated exploration of uncertainties arising from the various computer models involved. Two recent international projects generated a large suite of projections using multiple models2,3,4,5,6,7,8, but primarily used previous-generation scenarios9 and climate models10, and could not fully explore known uncertainties. Here we estimate probability distributions for these projections under the new scenarios11,12 using statistical emulation of the ice sheet and glacier models. We find that limiting global warming to 1.5 degrees Celsius would halve the land ice contribution to twenty-first-century sea level rise, relative to current emissions pledges. The median decreases from 25 to 13 centimetres sea level equivalent (SLE) by 2100, with glaciers responsible for half the sea level contribution. The projected Antarctic contribution does not show a clear response to the emissions scenario, owing to uncertainties in the competing processes of increasing ice loss and snowfall accumulation in a warming climate. However, under risk-averse (pessimistic) assumptions, Antarctic ice loss could be five times higher, increasing the median land ice contribution to 42 centimetres SLE under current policies and pledges, with the 95th percentile projection exceeding half a metre even under 1.5 degrees Celsius warming. This would severely limit the possibility of mitigating future coastal flooding. Given this large range (between 13 centimetres SLE using the main projections under 1.5 degrees Celsius warming and 42 centimetres SLE using risk-averse projections under current pledges), adaptation planning for twenty-first-century sea level rise must account for a factor-of-three uncertainty in the land ice contribution until climate policies and the Antarctic response are further constrained.
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- 2021
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11. initMIP-Antarctica: an ice sheet model initialization experiment of ISMIP6
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Hélène Seroussi, Sophie Nowicki, Erika Simon, Ayako Abe-Ouchi, Torsten Albrecht, Julien Brondex, Stephen Cornford, Christophe Dumas, Fabien Gillet-Chaulet, Heiko Goelzer, Nicholas R. Golledge, Jonathan M. Gregory, Ralf Greve, Matthew J. Hoffman, Angelika Humbert, Philippe Huybrechts, Thomas Kleiner, Eric Larour, Gunter Leguy, William H. Lipscomb, Daniel Lowry, Matthias Mengel, Mathieu Morlighem, Frank Pattyn, Anthony J. Payne, David Pollard, Stephen F. Price, Aurélien Quiquet, Thomas J. Reerink, Ronja Reese, Christian B. Rodehacke, Nicole-Jeanne Schlegel, Andrew Shepherd, Sainan Sun, Johannes Sutter, Jonas Van Breedam, Roderik S. W. van de Wal, Ricarda Winkelmann, and Tong Zhang
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- 2019
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12. Snow evolution through the Last Interglacial with a multi-layer snow model
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Thi Khanh Dieu Hoang, Aurélien Quiquet, Christophe Dumas, and Didier M. Roche
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The Last Interglacial period (LIG), which occurred approximately between 130 and 116 kyr BP, is characterized by similar/warmer temperatures and higher sea levels compared to the present-day conditions due to the orbital variation of the Earth. Hence, the period provides insights into the behavior of the Earth's system components under stable and prolonged warm climates and their subsequent evolution into a glacial state. To better understand the ice sheet's surface mass balance that ultimately drives the advance and retreat of ice-sheets, we study the snow cover changes in the Northern Hemisphere during the LIG. In order to do so, we used BESSI (BErgen Snow Simulator), a physical energy balance model with 15 vertical snow layers and high computational efficiency, to simulate the snowpack evolution. First, BESSI was validated using the regional climate model MAR (Modèle Atmosphérique Régional) as forcing and benchmark for snow cover over the Greenland and Antarctica Ice Sheets under present-day climate. Using two distinct ice sheet climates helps constrain the different processes in place (e.g., albedo and surface melt for Greenland and sublimation for Antarctica). For the LIG simulations, the latest version of an Earth system model of intermediate complexity iLOVECLIM was used to force BESSI in different time slices to fully capture the snow evolution in the Northern Hemisphere throughout this period. Impacts of the downscaling component of iLOVECLIM, which provides higher resolution data and accounts for the influences of the topography, on BESSI performance are also discussed. The results show that BESSI performs well compared to MAR for the present-day climate, even with a less complex model set-up. Through the LIG, with the ability to model the snow compaction, the change of snow density and snow depth, BESSI simulates the snow cover evolution in the studied area better than the simple snow model (bucket model) included in iLOVECLIM. The findings suggest that BESSI can provide a more physical surface mass balance scheme to ice sheet models such as GRISLI of iLOVECLIM to improve simulations of the ice sheet - climate interactions.
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- 2023
13. Antarctic ice sheet response to AMOC shutdowns during the penultimate deglaciation
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Maxence Menthon, Pepijn Bakker, Aurélien Quiquet, and Didier M. Roche
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According to geological records, the sea level during the Last Interglacial (∼ 129–116 ka) peaked 6 to 9 m higher than during the pre-industrial with a major contribution from the Antarctic ice sheet (Dutton et al. 2015). According to Clark et al. 2020, a longer period of reduced Atlantic Meridional Overturning Circulation (AMOC) during the penultimate deglaciation compared to the last deglaciation could have led to greater subsurface warming and subsequent larger Antarctic Ice Sheet retreat.Here we study the response of the Antarctic ice sheet to climate forcing with a forced AMOC shutdown at different timing and duration during the penultimate deglaciation (∼ 138–128 ka). The simulations are done with the Earth System Model of Intermediate Complexity iLOVECLIM (Roche et al. 2014) and the ice sheet model GRISLI (Quiquet et al. 2018), using the recently implemented sub-shelf melt module PICO (Reese et al. 2018). In the present simulations the GRISLI is forced with the iLOVECLIM simulations and is a step towards a fully coupled climate - ice sheet set up to take into account the climate - ice sheet interactions in a physical way.We hypothesize that both the duration and timing of reduced AMOC can significantly affect the sensitivity of the Antarctic Ice Sheet. A longer period of AMOC reduction will lead to a larger subsurface warming in the Southern Ocean and subsequently a larger ice sheet retreat. On the other hand, an AMOC reduction earlier (later) in the deglaciation implies that the ice sheet that is affected by this subsurface warming is still fairly large (already small). We will discuss both the individual as well as combined effect of duration and timing on the ice sheet evolution.
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- 2023
14. Supplementary material to 'Relative importance of the mechanisms triggering the Eurasian ice sheet deglaciation'
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Victor van Aalderen, Sylvie Charbit, Christophe Dumas, and Aurélien Quiquet
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- 2023
15. Deglacial climate changes as forced by different ice sheet reconstructions
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Nathaelle Bouttes, Fanny Lhardy, Aurélien Quiquet, Didier Paillard, Hugues Goosse, Didier M. Roche, 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), Modélisation du climat (CLIM), 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), Earth and Life Institute - Environmental Sciences (ELIE), Université Catholique de Louvain = Catholic University of Louvain (UCL), Cluster Earth and Climate [Amsterdam], Department of Earth Sciences [Amsterdam], Vrije Universiteit Amsterdam [Amsterdam] (VU)-Vrije Universiteit Amsterdam [Amsterdam] (VU), and UCL - SST/ELI/ELIC - Earth & Climate
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Global and Planetary Change ,[SDU]Sciences of the Universe [physics] ,Stratigraphy ,Paleontology - Abstract
During the last deglaciation, the climate evolves from a cold state at the Last Glacial Maximum (LGM) at 21 ka (thousand years ago) with large ice sheets to the warm Holocene at ∼9 ka with reduced ice sheets. The deglacial ice sheet melt can impact the climate through multiple ways: changes of topography and albedo, bathymetry and coastlines, and freshwater fluxes (FWFs). In the PMIP4 (Paleoclimate Modelling Intercomparison Project – Phase 4) protocol for deglacial simulations, these changes can be accounted for or not depending on the modelling group choices. In addition, two ice sheet reconstructions are available (ICE-6G_C and GLAC-1D). In this study, we evaluate all these effects related to ice sheet changes on the climate using the iLOVECLIM model of intermediate complexity. We show that the two reconstructions yield the same warming to a first order but with a different amplitude (global mean temperature of 3.9 ∘C with ICE-6G_C and 3.8 ∘C with GLAC-1D) and evolution. We obtain a stalling of temperature rise during the Antarctic Cold Reversal (ACR, from ∼14 to ∼12 ka) similar to proxy data only with the GLAC-1D ice sheet reconstruction. Accounting for changes in bathymetry in the simulations results in a cooling due to a larger sea ice extent and higher surface albedo. Finally, freshwater fluxes result in Atlantic meridional overturning circulation (AMOC) drawdown, but the timing in the simulations disagrees with proxy data of ocean circulation changes. This questions the causal link between reconstructed freshwater fluxes from ice sheet melt and recorded AMOC weakening.
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- 2023
16. The GRISLI-LSCE contribution to the Ice Sheet Model Intercomparison Project for phase 6 of the Coupled Model Intercomparison Project (ISMIP6) – Part 2: Projections of the Antarctic ice sheet evolution by the end of the 21st century
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Aurélien Quiquet, Christophe Dumas, 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), Modélisation du climat (CLIM), 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 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)
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lcsh:GE1-350 ,lcsh:Geology ,[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere ,010504 meteorology & atmospheric sciences ,13. Climate action ,lcsh:QE1-996.5 ,[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment ,010502 geochemistry & geophysics ,01 natural sciences ,lcsh:Environmental sciences ,0105 earth and related environmental sciences ,Earth-Surface Processes ,Water Science and Technology - Abstract
The Antarctic ice sheet's contribution to global sea level rise over the 21st century is of primary societal importance and remains largely uncertain as of yet. In particular, in the recent literature, the contribution of the Antarctic ice sheet by 2100 can be negative (sea level fall) by a few centimetres or positive (sea level rise), with some estimates above 1 m. The Ice Sheet Model Intercomparison Project for the Coupled Model Intercomparison Project – phase 6 (ISMIP6) aimed at reducing the uncertainties in the fate of the ice sheets in the future by gathering various ice sheet models in a common framework. Here, we present the GRISLI-LSCE (Grenoble Ice Sheet and Land Ice model of the Laboratoire des Sciences du Climat et de l'Environnement) contribution to ISMIP6-Antarctica. We show that our model is strongly sensitive to the climate forcing used, with a contribution of the Antarctic ice sheet to global sea level rise by 2100 that ranges from −50 to +150 mm sea level equivalent (SLE). Future oceanic warming leads to a decrease in thickness of the ice shelves, resulting in grounding-line retreat, while increased surface mass balance partially mitigates or even overcompensates the dynamic ice sheet contribution to global sea level rise. Most of the ice sheet changes over the next century are dampened under low-greenhouse-gas-emission scenarios. Uncertainties related to sub-ice-shelf melt rates induce large differences in simulated grounding-line retreat, confirming the importance of this process and its representation in ice sheet models for projections of the Antarctic ice sheet's evolution.
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- 2021
17. Response of the Wilkes Subglacial Basin Ice Sheet to Southern Ocean Warming During Late Pleistocene Interglacials
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Ilaria Crotti, Aurélien Quiquet, Amaelle Landais, Barbara Stenni, Massimo Frezzotti, David Wilson, Mirko Severi, Robert Mulvaney, Frank Wilhelms, and Carlo Barbante
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The growth and decay of marine ice sheets act as important controls on regional and global climate and sea level. The Wilkes Subglacial Basin ice sheet appears to have undergone thinning and ice discharge events during recent decades, but its past dynamics are still under debate. The aim of our study is to investigate ice margin retreat of the Wilkes Subglacial Basin ice sheet during late Pleistocene interglacials with the help of new high-resolution records from the TALDICE ice core. Here we present a multiproxy approach associated with modelling sensitivity experiments.The novel high-resolution δ18O signal reveals that interglacial periods MIS 7.5 and 9.3 are characterized by a unique double-peak feature, previously observed for MIS 5.5 (Masson-Delmotte et al., 2011), that is not seen in other Antarctic ice cores. A comparison with our GRISLI modelling results indicates that the Talos Dome site has probably undergone elevation variations of 100-400 m during past interglacials, with a major ice thickness variation during MIS 9.3, likely connected to a relevant margin retreat of the Wilkes Subglacial Basin ice sheet. To validate this elevation change hypothesis, the modelling outputs are compared to the ice-rafted debris record (IBRD) and the neodymium isotope signal from the U1361A sediment core (Wilson et al., 2018), which show that during MIS 5.5 and especially MIS 9.3, the Wilkes Subglacial Basin ice sheet has been subjected to ice discharge events.Overall, our results indicate that the interglacial double-peak δ18O signal could reflect decreases in Talos Dome site elevation during the late stages of interglacials due to Wilkes Subglacial Basin retreat events. These changes coincided with warmer Southern Ocean temperatures and elevated global mean sea level, confirming the sensitivity of the Wilkes Subglacial Basin ice sheet to ocean warming and its potential role in sea-level change.
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- 2022
18. Antarctic-climate multi-millenia coupled simulations under different pCO2 levels with the iLOVECLIM-GRISLI model
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Gaelle Leloup, Aurélien Quiquet, Christophe Dumas, Didier Roche, and Didier Paillard
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Ice sheets and the rest of the climate system interact in various ways, notably via the atmosphere, ocean and solid earth. Atmospheric and oceanic temperatures and circulations affect the evolution of ice-sheets, and conversely ice-sheet evolution impacts the rest of the climate system via various processes, including albedo modification, topographic changes and freshwater flux release into the ocean. To correctly model the evolution of the climate system and sea level rise, these feedbacks therefore need to be considered.Under the highest emission scenario, temperature is expected to reach levels comparable to the Eocene epoch in a few centuries [1]. At this time, there was no widespread glaciation in Antarctica.The work of Garbe et al [2] has shown that the Antarctic ice sheet has a hysteresis behavior and gave different temperature thresholds leading to committed Antarctic mass loss. For example, between 6 and 9 degrees of warming (a global temperature increase comparable to the one expected in 2300 for the most emissive scenario), the loss of 70% of the present-day ice volume is triggered. However, the modelling study used idealized perturbations of the climate fields based solely on global mean temperature. More specifically, global mean temperature is translated into local changes of ocean and surface air temperature and increased until a complete deglaciation of the Antarctic ice-sheet is reached. In addition the study did not take into account the ice sheet change feedback on the climate system.In our work we intend to go a step further by taking into account both the influence of atmosphere and oceanic temperature and circulations on the ice sheet in a physical way, as well as the influence of the ice sheet on the rest of the climate system.To do so, we use the coupled ocean-atmosphere-vegetation intermediate complexity model iLOVECLIM [3], fully coupled to the GRISLI ice-sheet model for Antarctica [4, 5].We perform several multi-millenia equilibria simulations for different pCO2 levels, thanks to the relative rapidity of both the iLOVECLIM and GRISLI models. These simulations lead to different atmospheric and oceanic temperatures and Antarctic mass loss. These coupled simulations allow us to explore the impact of the ice sheet feedback on the climate and to investigate the differences compared to cases where these feedbacks are not included. The influence of the model parameters linked to the ice sheet coupling is also studied. References :[1] Westerhold et al 2020, “An astronomically dated record of Earth’s climate and its predictability over the last 66 million years”[2] Garbe et al 2020 “The hysteresis of the Antarctic Ice Sheet”[3] Quiquet et al 2018, “Online dynamical downscaling of temperature and precipitation within the iLOVECLIM model (version 1.1)”[4] Quiquet et al 2018, “The GRISLI ice sheet model (version 2.0): calibration and validation for multi-millennial changes of the Antarctic ice sheet”[5] Quiquet et al 2021 “Climate and ice sheet evolutions from the last glacial maximum to the pre-industrial period with an ice-sheet–climate coupled model”
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- 2022
19. Antarctic sub-shelf melt during the present and the last interglacial and its impact on ice sheet dynamics
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Maxence Menthon, Pepijn Bakker, Aurélien Quiquet, and Didier Roche
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The response of ice sheets to climate changes can be diverse and complex. The amplitude, speed and irreversibility of the melting of the ice sheets due to current anthropogenic emissions remain largely uncertain after 2100. Being able to reconstruct the evolution of the ice sheets during the past climate changes is a possible approach to constrain their future evolution in time scales further than the end of the century.Here we aim to reconstruct the evolution of the Antarctic ice sheet during the Last Interglacial (LIG, ~ 130 to 115 kyr BP). The LIG was 0.5 to 1˚C warmer than the pre-industrial era with a sea-level between 6 to 9 m above present level. In other words, the Antarctic ice sheet during the LIG can be considered as an analogue to its future evolution. Moreover, it is the interglacial on which we have the most geological records to compare with simulation results.Knowing that the oceanic forcing is the main driver of the Antarctic ice sheet retreat, we introduced the sub-shelf melt module PICO (Reese et al. 2018) in the ice sheet model (GRISLI, Quiquet et al. 2018) in order to physically compute the melt. We use outputs from the Earth Sytem Model (iLOVECLIM, Roche et al. 2014) to force idealized experiments. Several time periods will be covered: present-day, last glacial maximum and LIG. This work is a first step towards a fully coupled iLOVECLIM-GRISLI-PICO simulation to explicitly take into account the ice sheet climate - interactions in a physical way in simulations of the Antarctic ice sheet during the LIG and future centuries.
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- 2022
20. Validation of a CDF-t bias correction method using palaeo-data for the Mid-Holocene and the Last Glacial Maximum
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Anhelina Zapolska, Mathieu Vrac, Aurélien Quiquet, Frank Arthur, Hans Renssen, Louis François, and Didier M. Roche
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The main objective of this study is to develop and test a method of bias correction for paleoclimate model simulations using the “Cumulative Distribution Functions – transform” (CDF-t) method. The CDF-t is a quantile-mapping based method, extended to account for climate change signal. Here we apply the CDF-t to climate model outputs for the Mid-Holocene and the Last Glacial Maximum, simulated by the climate model of intermediate complexity iLOVECLIM at 5.625° resolution. Additionally, we test the proposed methodology on iLOVECLIM model outputs dynamically downscaled on a 0.25° resolution.The results are validated through inverse and forward modelling approaches. The inverse approach implies comparing the obtained results with proxy-based reconstructed climatic variables. Here we use temperature and precipitation reconstructions, obtained with inverse modelling methods from pollen data. In this study, both gridded and point-based multi-proxy reconstruction datasets were used for the analysis.The forward approach includes a further step of vegetation modelling, using the climatologies derived from bias-corrected outputs of the iLOVECLIM model in CARAIB (CARbon Assimilation In the Biosphere) global dynamic vegetation model. The modelled biomes are evaluated in comparison with pollen-based biome reconstructions BIOME6000.The findings of this study indicate that the use of the proposed methodology results in significant improvements in climate and vegetation modelling and suggest that the CDF-t method is an valuable approach to reduce biases in paleoclimate modelling.
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- 2022
21. The last deglaciation of the Eurasian ice sheet (21,000 - 8,000 yr BP): a sensitivity study to PMIP3/PMIP4 coupled atmosphere-ocean models outputs
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Victor van Aalderen, Sylvie Charbit, Christophe Dumas, and Aurélien Quiquet
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Rapid sea-level rise, due to melting and destabilization of present-day ice sheets will likely have important consequences on human societies. Observations provide evidences of increased mass loss in the West Antarctic Ice Sheet (WAIS) over the recent decades, partly due to ocean warming. Despite improvements in both climate and ice-sheet models, there are still significant uncertainties about the future of West Antarctica, due, in part, to our misunderstanding of the process responsible for the marine ice sheet evolution. Paleoclimate studies provide important information on ice-sheet collapse in a warming world.Our study is based on the Eurasian Ice Sheet (EIS) complex, including the British Island Ice Sheet (BIIS), the Fennoscandian Ice Sheet (FIS) and the Barents Kara Ice Sheet (BKIS). Because large parts of both the BKIS and the WAIS are marine-based, the BKIS at the LGM can be considered as a potential analogue to the WAIS.To improve our understanding of the mechanisms responsible for the EIS retreat, we performed transient simulations of the last EIS deglaciation (21 000 – 8 000 yr BP) with the GRISLI ice sheet model forced by 5 PMIP3/PMIP4 models, and two transients GCM models, TRACE21K and iLOVECLIM. Our main goal is to investigate the sensitivity of the EIS grounding line retreat to climate forcing, sea-level rise and glaciological processes with a focus on the BKIS evolution during the deglaciation and the behaviour of the large Bjornoyrenna ice stream.
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- 2022
22. The PMIP4 Last Glacial Maximum experiments: preliminary results and comparison with the PMIP3 simulations
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Didier M. Roche, Gerrit Lohmann, Nathaelle Bouttes, Ruza F. Ivanovic, Kenji Izumi, Xiaoxu Shi, Rumi Ohgaito, Deepak Chandan, Lauren Gregoire, Marie Kapsch, Jessica E. Tierney, Evgeny Volodin, Christopher J. Poulsen, Uwe Mikolajewicz, Sam Sherriff-Tadano, Marcus Lofverstrom, Polina Morozova, André Paul, Jiang Zhu, Masa Kageyama, Fanny Lhardy, Tristan Vadsaria, Sandy P. Harrison, W. Richard Peltier, Paul J. Valdes, Juan M. Lora, Ayako Abe-Ouchi, Allegra N. LeGrande, Aurélien Quiquet, Earth Sciences, 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), Modélisation du climat (CLIM), 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), School of Archaeology, Geography and Environmental Sciences (SAGES), University of Reading (UOR), Max Planck Institute for Meteorology (MPI-M), Max-Planck-Gesellschaft, University of Arizona, Yale University [New Haven], 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)
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010504 meteorology & atmospheric sciences ,Stratigraphy ,Climate change ,010502 geochemistry & geophysics ,Environmental protection ,01 natural sciences ,Environmental pollution ,TD169-171.8 ,Paleoclimatology ,GE1-350 ,Precipitation ,SDG 14 - Life Below Water ,[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment ,0105 earth and related environmental sciences ,[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere ,Global and Planetary Change ,Coupled model intercomparison project ,Paleontology ,Environmental sciences ,TD172-193.5 ,13. Climate action ,Climatology ,Paleoclimate Modelling Intercomparison Project ,Polar amplification ,Environmental science ,Climate model ,Global cooling - Abstract
The Last Glacial Maximum (LGM, ∼ 21 000 years ago) has been a major focus for evaluating how well state-of-the-art climate models simulate climate changes as large as those expected in the future using paleoclimate reconstructions. A new generation of climate models has been used to generate LGM simulations as part of the Paleoclimate Modelling Intercomparison Project (PMIP) contribution to the Coupled Model Intercomparison Project (CMIP). Here, we provide a preliminary analysis and evaluation of the results of these LGM experiments (PMIP4, most of which are PMIP4-CMIP6) and compare them with the previous generation of simulations (PMIP3, most of which are PMIP3-CMIP5). We show that the global averages of the PMIP4 simulations span a larger range in terms of mean annual surface air temperature and mean annual precipitation compared to the PMIP3-CMIP5 simulations, with some PMIP4 simulations reaching a globally colder and drier state. However, the multi-model global cooling average is similar for the PMIP4 and PMIP3 ensembles, while the multi-model PMIP4 mean annual precipitation average is drier than the PMIP3 one. There are important differences in both atmospheric and oceanic circulations between the two sets of experiments, with the northern and southern jet streams being more poleward and the changes in the Atlantic Meridional Overturning Circulation being less pronounced in the PMIP4-CMIP6 simulations than in the PMIP3-CMIP5 simulations. Changes in simulated precipitation patterns are influenced by both temperature and circulation changes. Differences in simulated climate between individual models remain large. Therefore, although there are differences in the average behaviour across the two ensembles, the new simulation results are not fundamentally different from the PMIP3-CMIP5 results. Evaluation of large-scale climate features, such as land–sea contrast and polar amplification, confirms that the models capture these well and within the uncertainty of the paleoclimate reconstructions. Nevertheless, regional climate changes are less well simulated: the models underestimate extratropical cooling, particularly in winter, and precipitation changes. These results point to the utility of using paleoclimate simulations to understand the mechanisms of climate change and evaluate model performance.
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- 2021
23. Deglacial Ice Sheet Instabilities Induced by Proglacial Lakes
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Gilles Ramstein, Catherine Ritz, Aurélien Quiquet, Didier Paillard, Didier M. Roche, Christophe Dumas, 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), Modélisation du climat (CLIM), 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 national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), 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), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), and Earth Sciences
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[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere ,geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,North American ice sheet ,Northern Hemisphere ,010502 geochemistry & geophysics ,01 natural sciences ,grounding line instability ,Geophysics ,13. Climate action ,Deglaciation ,General Earth and Planetary Sciences ,Physical geography ,SDG 14 - Life Below Water ,Ice sheet ,last deglaciation ,proglacial lake ,[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment ,Geology ,0105 earth and related environmental sciences - Abstract
International audience; During the last deglaciation (21–7 kaBP), the gradual retreat of Northern Hemisphere ice sheet margins produced large proglacial lakes. While the climatic impacts of these lakes have been widely acknowledged, their role on ice sheet grounding line dynamics has received very little attention so far. Here, we show that proglacial lakes had dramatic implications for the North American ice sheet dynamics through a self‐sustained mechanical instability which has similarities with the known marine ice sheet instability consequently providing fast retreat of large portions of the ice sheet over the continent. This instability mechanism is likely important in contributing to deglaciation of terrestrial glaciers and ice sheets with proglacial lakes at their margins as it can substantially accelerate the mass loss. Echoing our knowledge of Antarctic ice sheet dynamics, proglacial lakes are another manifestation of the importance of grounding line dynamics for ice sheet evolution.
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- 2021
24. Projected land ice contributions to twenty-first-century sea level rise
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Luke D. Trusel, Brian Anderson, Youngmin Choi, Michiel R. van den Broeke, Courtney Shafer, Cheng Zhao, William H. Lipscomb, Erika Simon, Sébastien Le clec'h, Victoria Lee, Thomas Kleiner, Donald Slater, Tore Hattermann, Matthias Huss, James F. O’Neill, Sainan Sun, Philip Kraaijenbrink, Benjamin K. Galton-Fenzi, Ayako Abe-Ouchi, Richard I. Cullather, Christophe Dumas, Christopher J. Smith, Nicolas C. Jourdain, Eric Larour, Rupert Gladstone, Jonas Van Breedam, Xavier Fettweis, Christine M. McKenna, Fiona Turner, Nicole Schlegel, Patrick Alexander, Walter W. Immerzeel, Gunter R. Leguy, Torsten Albrecht, Nicholas R. Golledge, Fabien Maussion, Fiammetta Straneo, Valentina Radić, Antony J. Payne, Robin S. Smith, Andrew Bliss, Heiko Goelzer, Andrew Shepherd, Frank Pattyn, Lev Tarasov, Mathieu Morlighem, Christopher Chambers, Tamsin L. Edwards, Reinhard Calov, Koji Fujita, Harry Zekollari, Nicolas Champollion, Akiko Sakai, Sarah Shannon, Ralf Greve, Stephen Price, Isabel Nias, Ricarda Winkelmann, David R. Rounce, Tong Zhang, Jan Hendrik Malles, Ben Marzeion, Roderik S. W. van de Wal, Helene Seroussi, Christopher M. Little, Cécile Agosta, Martin Rückamp, Philippe Huybrechts, Regine Hock, Angelika Humbert, Xylar Asay-Davis, Denis Felikson, Aurélien Quiquet, Daniel F. Martin, Andy Aschwanden, Matthew J. Hoffman, Tyler Pelle, Ronja Reese, Jonathan M. Gregory, Thomas Zwinger, Alice Barthel, Sophie Nowicki, J. K. Cuzzone, Daniel P. Lowry, 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), Modélisation du climat (CLIM), Fonds De La Recherche Scientifique - FNRS, FNRS Horizon 2020: 820829 Australian Government: ASCI000002 Horizon 2020 Framework Programme, H2020: 869304 U.S. Department of Energy, USDOE O0100718F British Antarctic Survey, BAS Bundesministerium für Bildung und Forschung, BMBF: 01LP1504D, FKZ 01LP1502C Ministerie van Onderwijs, Cultuur en Wetenschap, OCW: 024.002.001 Natural Environment Research Council, NERC: NE/T007443/1 Deutsche Forschungsgemeinschaft, DFG: WI4556/2-1, 01LP1925D, WI4556/4-1 Norges Forskningsråd: 270061, 295046 American Research Center in Sofia, ARCS National Science Foundation, NSF: 1852977 National Center for Atmospheric Research, NCAR Horizon 2020 Framework Programme, H2020: NNX17AG65G, 820575 U.S. Department of Energy, USDOE Japan Society for the Promotion of Science, KAKEN: JP16H02224, JP17H06104, JP17H06323 Ministerie van Onderwijs, Cultuur en Wetenschap, OCW Office of Science, SC Suomen Akatemia: 286587, 322430 National Centre for Atmospheric Science, NCAS National Aeronautics and Space Administration, NASA Netherlands Earth System Science Centre, NESSC European Space Agency, ESA U.S. Department of Energy, USDOE Belgian Federal Science Policy Office, BELSPO: SR/00/336 National Science Foundation, NSF: PLR-1644277, PLR-1603799 Universiteit Utrecht, UU European Regional Development Fund, ERDF Bundesministerium für Bildung und Forschung, BMBF: WI4556/3-1 Ministry of Education, Culture, Sports, Science and Technology, Monbusho National Aeronautics and Space Administration, NASA Natural Environment Research Council, NERC Natural Environment Research Council, NERC Ministry for Business Innovation and Employment, MBIE: RTUV1705, ANTA1801 International Institute for Applied Systems Analysis, IIASA: NE/T009381/1 Biological and Environmental Research, BER: DE-AC02-05CH11231 Australian Research Council, ARC: SR140300001 European Commission, EC Office of Science, SC: DE-SC0020073 Ministry of Education, Culture, Sports, Science and Technology, Monbusho: JPMXD1420318865, JPMXD1300000000 Advanced Scientific Computing Research, ASCR, Acknowledgements We thank J. Rougier for providing advice and support throughout, and writing the original random effects model. We also thank B. Fox-Kemper, H. Hewitt, R. Kopp, S. Drijfhout and J. Rohmer for discussions, suggestions and support. We thank N. Barrand, W. Chang, V. Volodina and D. Williamson for their thorough and constructive comments, which greatly improved the manuscript. We thank the Climate and Cryosphere (CliC) Project, which provided support for ISMIP6 and GlacierMIP through sponsoring of workshops, hosting the websites and ISMIP6 wiki, and promotion. We acknowledge the World Climate Research Programme, which, through its Working Group on Coupled Modelling, coordinated and promoted CMIP5 and CMIP6. We thank the climate modelling groups for producing and making available their model output, the Earth System Grid Federation (ESGF) for archiving the CMIP data and providing access, the University at Buffalo for ISMIP6 data distribution and upload, and the multiple funding agencies who support CMIP5 and CMIP6 and ESGF. We thank the ISMIP6 steering committee, the ISMIP6 model selection group and the ISMIP6 dataset preparation group for their continuous engagement in defining ISMIP6. This is ISMIP6 contribution no. 13. This publication was supported by PROTECT, which has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 869304. This is PROTECT contribution number 12. T.L.E. was supported by PROTECT and the UK Natural Environment Research Council grant NE/T007443/1. F.T. was supported by PROTECT. J.F.O’N. was supported by the UK Natural Environment Research Council London Doctoral Training Partnership. R. Gladstone’s contribution was supported by Academy of Finland grants 286587 and 322430, and T. Zwinger’s by grant 322430. W.H.L. and G.R.L. were supported by the National Center for Atmospheric Research, which is a major facility sponsored by the National Science Foundation under Cooperative Agreement no. 1852977. Computing and data storage resources for CISM simulations, including the Cheyenne supercomputer (https://doi.org/10.5065/D6RX99HX), were provided by the Computational and Information Systems Laboratory (CISL) at NCAR. Support for X.A.-D., M.J.H., S.F.P. and T. Zhang was provided through the Scientific Discovery through Advanced Computing (SciDAC) programme funded by the US Department of Energy (DOE), Office of Science, Advanced Scientific Computing Research and Biological and Environmental Research programmes. N.R.G., D.P.L. and B.A. were supported by New Zealand Ministry for Business, Innovation and Employment contracts RTUV1705 (‘NZSeaRise’) and ANTA1801 (‘Antarctic Science Platform’). J.M.G. and R.S.S. were supported by the National Centre for Atmospheric Science, funded by the UK National Environment Research Council. R. Calov was funded by the PalMod project of the Bundesministerium für Bildung und Forschung (BMBF) with the grants FKZ 01LP1502C and 01LP1504D. D.F.M. and C.S. were supported by the Director, Office of Science, Offices of Advanced Scientific Computing Research (ASCR) and Biological and Environmental Research (BER), of the US Department of Energy under contract no. DE-AC02-05CH11231, as a part of the ProSPect SciDAC Partnership. BISICLES simulations used resources of the National Energy Research Scientific Computing Center (NERSC), a US Department of Energy Office of Science User Facility operated under contract no. DE-AC02-05CH11231. C.Z. and B.K.G.-F. were supported under the Australian Research Council’s Special Research Initiative for Antarctic Gateway Partnership (project ID SR140300001) and received grant funding from the Australian Government for the Australian Antarctic Program Partnership (project ID ASCI000002). Work was performed by E.L., N.-J.S. and H.S. at the California Institute of Technology’s Jet Propulsion Laboratory under a contract with the National Aeronautics and Space Administration, support was provided by grants from NASA’s Cryospheric Science, Sea Level Change Team, and Modeling, Analysis and Prediction (MAP) programmes. They acknowledge computational resources and support from the NASA Advanced Supercomputing Division. The CMIP5 and CMIP6 projection data were processed by C.M.M. with funding from the European Union’s CONSTRAIN project as part of the Horizon 2020 Research and Innovation Programme under grant agreement number 820829. A. Barthel was supported by the DOE Office of Science HiLAT-RASM project and Early Career Research programme. T.A. and R.W. are supported by the Deutsche Forschungsgemeinschaft (DFG) in the framework of the priority programme ‘Antarctic research with comparative investigations in Arctic ice areas’ by grants WI4556/2-1 and WI4556/4-1, and within the framework of the PalMod project (FKZ: 01LP1925D) supported by the German Federal Ministry of Education and Research (BMBF) as a Research for Sustainability initiative (FONA). R.R. is supported by the Deutsche Forschungsgemeinschaft (DFG) by grant WI4556/3-1 and through the TiPACCs project that receives funding from the European Union’s Horizon 2020 Research and Innovation programme under grant agreement no. 820575. Development of PISM is supported by NASA grant NNX17AG65G and NSF grants PLR-1603799 and PLR-1644277. The authors gratefully acknowledge the European Regional Development Fund (ERDF), the German Federal Ministry of Education and Research and the Land Brandenburg for supporting this project by providing resources for the high-performance computer system at the Potsdam Institute for Climate Impact Research. Computer resources for this project have also been provided by the Gauss Centre for Supercomputing, Leibniz Supercomputing Centre (http://www.lrz.de, last access: 16 July 2020) under project IDs pr94ga and pn69ru. R. Greve and C.C. were supported by Japan Society for the Promotion of Science (JSPS) KAKENHI grant nos JP16H02224 and JP17H06323. R. Greve was supported by JSPS KAKENHI grant no. JP17H06104, by a Leadership Research Grant of Hokkaido University’s Institute of Low Temperature Science (ILTS), and by the Arctic Challenge for Sustainability (ArCS, ArCS II) project of the Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT) (programme grant nos JPMXD1300000000, JPMXD1420318865). F.P. and S. Sun were supported by the MIMO project within the STEREO III programme of the Belgian Science Policy Office, contract SR/00/336 and the Fonds de la Recherche Scientifique (FNRS) and the Fonds Wetenschappelijk Onderzoek-Vlaanderen (FWO) under the EOS project no. O0100718F. A. Shepherd was supported by the UK Natural Environment Research Council in partnership with the Centre for Polar Observation and Modelling and the British Antarctic Survey and by the European Space Agency Climate Change Initiative. D.F. was supported by an appointment to the NASA Postdoctoral Program at the NASA Goddard Space Flight Center, administered by Universities Space Research Association under contract with NASA. R.v.d.W. acknowledges the support of the Future Deltas programme of Utrecht University. C.J.S. was supported by a NERC/IIASA Collaborative Research Fellowship (NE/T009381/1). H.G. has received funding from the programme of the Netherlands Earth System Science Centre (NESSC), financially supported by the Dutch Ministry of Education, Culture and Science (OCW) under grant no. 024.002.001 and from the Research Council of Norway under projects INES (270061) and KeyClim (295046). F.S. acknowledges support from DOE Office of Science grant no. DE-SC0020073. High-performance computing and storage resources were provided by the Norwegian Infrastructure for Computational Science through projects NN9560K, NN9252K, NS9560K, NS9252K and NS5011K., University of St Andrews. School of Geography & Sustainable Development, University of St Andrews. Environmental Change Research Group, 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), Sub Dynamics Meteorology, Hydrologie, Landscape functioning, Geocomputation and Hydrology, Proceskunde, Sub Algemeen Marine & Atmospheric Res, Earth System Sciences, Geography, Physical Geography, and Faculty of Sciences and Bioengineering Sciences
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010504 meteorology & atmospheric sciences ,General Science & Technology ,[SDV]Life Sciences [q-bio] ,01 natural sciences ,010104 statistics & probability ,Taverne ,G1 ,SDG 13 - Climate Action ,0101 mathematics ,General ,Coastal flood ,Sea level ,0105 earth and related environmental sciences ,geography ,Multidisciplinary ,geography.geographical_feature_category ,Global warming ,G Geography (General) ,DAS ,Glacier ,Glaciologie ,Snow ,Climate Action ,Current (stream) ,Sea level rise ,13. Climate action ,Climatology ,Environmental science ,Ice sheet ,Sciences exactes et naturelles - Abstract
The land ice contribution to global mean sea level rise has not yet been predicted 1 using ice sheet and glacier models for the latest set of socio-economic scenarios, nor using coordinated exploration of uncertainties arising from the various computer models involved. Two recent international projects generated a large suite of projections using multiple models 2–8, but primarily used previous-generation scenarios 9 and climate models 10, and could not fully explore known uncertainties. Here we estimate probability distributions for these projections under the new scenarios 11,12 using statistical emulation of the ice sheet and glacier models. We find that limiting global warming to 1.5 degrees Celsius would halve the land ice contribution to twenty-first-century sea level rise, relative to current emissions pledges. The median decreases from 25 to 13 centimetres sea level equivalent (SLE) by 2100, with glaciers responsible for half the sea level contribution. The projected Antarctic contribution does not show a clear response to the emissions scenario, owing to uncertainties in the competing processes of increasing ice loss and snowfall accumulation in a warming climate. However, under risk-averse (pessimistic) assumptions, Antarctic ice loss could be five times higher, increasing the median land ice contribution to 42 centimetres SLE under current policies and pledges, with the 95th percentile projection exceeding half a metre even under 1.5 degrees Celsius warming. This would severely limit the possibility of mitigating future coastal flooding. Given this large range (between 13 centimetres SLE using the main projections under 1.5 degrees Celsius warming and 42 centimetres SLE using risk-averse projections under current pledges), adaptation planning for twenty-first-century sea level rise must account for a factor-of-three uncertainty in the land ice contribution until climate policies and the Antarctic response are further constrained.
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- 2021
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25. Climate and ice sheet evolutions from the last glacial maximum to the pre-industrial period with an ice sheet – climate coupled model
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Aurélien Quiquet, Didier M. Roche, Christophe Dumas, Nathaëlle Bouttes, and Fanny Lhardy
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The last deglaciation offers an unique opportunity to understand the climate – ice sheet interactions in a global warming context. In this paper, to tackle this question, we use an Earth system model of intermediate complexity coupled to an ice sheet model covering the Northern Hemisphere to simulate the last deglaciation and the Holocene (26–0 ka BP). We use a synchronous coupling every year between the ice sheet and the rest of the climate system and we ensure a closed water cycle considering the release of freshwater flux to the ocean due to ice sheet melting. Our reference experiment displays a gradual warming in response to the forcings, with no abrupt changes. In this case, while the amplitude of the freshwater flux to the ocean induced by ice sheet retreat is realistic, it is sufficient to shut down the Atlantic meridional overturning from which the model does not recover within the time period simulated. However, with reduced freshwater flux we are nonetheless able to obtain different oceanic circulation evolutions, including some abrupt transitions between shut-down and active circulation states in the course of the deglaciation. The fast oceanic circulation recoveries lead to abrupt warming phases in Greenland. Our simulated ice sheet geometry evolution is in overall good agreement with available global reconstructions, even though the abrupt sea level rise at 14.6 kaBP is underestimated, possibly because the climate model underestimates the millenial- scale temperature variability. In the course of the deglaciation, large-scale grounding line instabilities are simulated both for the Eurasian and North American ice sheets. The first instability occurs in the Barents-Kara seas for the Eurasian ice sheet at 14.5 kaBP. A second grounding line instability occurs circa 12 kaBP in the proglacial lake that formed at the southern margin of the North American ice sheet. With additional asynchronously coupled experiments, we assess the sensitivity of our results to different ice sheet model choices related to surface and sub-shelf mass balance, ice deformation and grounding line representation. While the ice sheet evolutions differ within this ensemble, the global climate trajectory is only weakly affected by these choices. In our experiments, only the abrupt shifts in the oceanic circulation due to freshwater fluxes are able to produce some millenial-scale variability since no self-generating abrupt transitions are simulated without these fluxes.
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- 2021
26. Impact of ice sheet reconstructions on the deglacial climate in iLOVECLIM
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Aurélien Quiquet, Hugues Goosse, Nathaelle Bouttes, Didier M. Roche, Fanny Lhardy, and Didier Paillard
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geography ,geography.geographical_feature_category ,Climatology ,Ice sheet ,Geology - Abstract
The last deglaciation is a time of large climate transition from a cold Last Glacial Maximum at 21,000 years BP with extensive ice sheets, to the warmer Holocene 9,000 years BP onwards with reduced ice sheets. Despite more and more proxy data documenting this transition, the evolution of climate is not fully understood and difficult to simulate. The PMIP4 protocol (Ivanovic et al., 2016) has indicated which boundary conditions to use in model simulations during this transition. The common boundary conditions should enable consistent multi model and model-data comparisons. While the greenhouse gas concentration evolution and orbital forcing are well known and easy to prescribe, the evolution of ice sheets is less well constrained and several choices can be made by modelling groups. First, two ice sheet reconstructions are available: ICE-6G (Peltier et al., 2015) and GLAC-1D (Tarasov et al., 2014). On top of topographic changes, it is left to modelling groups to decide whether to account for the associated bathymetry and land-sea mask changes, which is technically more demanding. These choices could potentially lead to differences in the climate evolution, making model comparisons more complicated.We use the iLOVECLIM model of intermediate complexity (Goosse et al., 2010) to evaluate the impact of different ice sheet reconstructions and the effect of bathymetry changes on the global climate evolution during the Last deglaciation. We test the two ice sheet reconstructions (ICE-6G and GLAC-1D), and have implemented changes of bathymetry and land-sea mask. In addition, we also evaluate the impact of accounting for the Antarctic ice sheet evolution compared to the Northern ice sheets only.We show that despite showing the same long-term changes, the two reconstructions lead to different evolutions. The bathymetry plays a role, although only few changes take place before ~14ka. Finally, the impact of the Antarctic ice sheet is important during the deglaciation and should not be neglected.ReferencesGoosse, H., et al., Description of the Earth system model of intermediate complexity LOVECLIM version 1.2, Geosci. Model Dev., 3, 603–633, https://doi.org/10.5194/gmd-3-603-2010, 2010Ivanovic, R. F., et al., Transient climate simulations of the deglaciation 21–9 thousand years before present (version 1) – PMIP4 Core experiment design and boundary conditions, Geosci. Model Dev., 9, 2563–2587, https://doi.org/10.5194/gmd-9-2563-2016, 2016Peltier, W. R., Argus, D. F., and Drummond, R., Space geodesy constrains ice age terminal deglaciation: The global ICE-6G_C (VM5a) model, J. Geophys. Res.-Sol. Ea., 120, 450–487, doi:10.1002/2014JB011176, 2015Tarasov,L., et al., The global GLAC-1c deglaciation chronology, melwater pulse 1-a, and a question of missing ice, IGS Symposium on Contribution of Glaciers and Ice Sheets to Sea-Level Change, 2014
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- 2021
27. Developing an emulator to calculate present temperature field in the Antarctic Ice Sheet
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Ghislain Picard, Aurélien Quiquet, Christophe Dumas, Marion Leduc-Leballeur, Giovanni Macelloni, and Catherine Ritz
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Field (physics) ,Antarctic ice sheet ,Geophysics ,Geology - Abstract
Ice temperature within the ice is a crucial characteristic to understand the Antarctic ice sheet evolution because temperature is coupled to ice flow. Since temperature is only measured at few locations in deep boreholes, we only rely on numerical modelling to assess ice sheet-wide temperature. However, the design of such models leads to a number of challenges. One important difficulty is that the temperature field strongly depends on the geothermal flux which is still poorly known (see White paper by Burton-Johnson and others,2020 ). Another point is that up to now there is no fully suitable model, especially for inverse approaches: i) analytical solutions are only valid in slowly flowing regions; ii) models solving only the heat equation by prescribing geometry and ice flow do not take into account the past changes in ice thickness and ice flow and do not couple ice flow and temperature. Conversely, 3D thermomechanical models that simulate the evolution of the ice sheet take into account all the relevant processes but they are too computationally expensive to be used in inverse approaches. Moreover, they do not provide a perfect fit between observed and simulated geometry (ice thickness, surface elevation) for the present-day ice sheets and this affects the simulated temperature field.GRISLI (Quiquet et al. 2018), belongs to this family of thermomechanically coupled ice sheet models An emulator, based on deep neural network (DNN), has been developed in order to speed-up the simulation of present-day ice temperature. We use GRISLI outputs that come from 4 simulations, each covers 900000 years (8 glacial-interglacial cycles) to get rid of the initial configuration influence. The simulations differ by the geothermal flux map used as boundary condition. Finally a database is built where each ice column for each simulation is a sample used to train the DNN. For each sample, the input layer (precursor) is a vector of the present-day characteristics: ice thickness, surface temperature, geothermal flux, accumulation rate, surface velocity and surface slope. The predicted output (output layer) is the vertical profile of temperature. In the training, the weights of the network are optimized by comparison with the GRISLI temperature. The first results are very encouraging with a RMSE of ~ 0.6 °C (calculated from the difference between the emulated temperatures and GRISLI temperatures over all the samples and all the depths). Once trained, the computational time of GRISLI-DNN for generating temperature field of whole Antarctica (16000 columns) is about 20 s.The first application (in the framework of the ESA project 4D-Antarctica, see Leduc-Leballeur presentation in this session) will be to use this emulator associated with SMOS satellite observations to infer the 3D temperature field and improve our knowledge of geothermal flux. Indeed, it has been shown that SMOS data, coupled with glaciological and electromagnetic models, give an indication of temperature in the upper 1000 m of the ice sheet. Our emulator could also be used for initialization of computationally expensive ice sheet models.
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- 2021
28. The unique behavior of stable water isotopes profiles during interglacial periods at Talos Dome, Antarctica
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Ilaria Crotti, Giuliano Dreossi, Bénédicte Minster, Aurélien Quiquet, Frédéric Prié, Barbara Stenni, Amaelle Landais, Massimo Frezzotti, and Carlo Barbante
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Paleontology ,Dome (geology) ,Isotope ,biology ,Talos ,Interglacial ,biology.organism_classification ,Geology - Abstract
The growth and decay of marine ice sheets act as important controls on regional and global climate, in particular, the behavior of the ice sheets is a key uncertainty in predicting sea-level rise during and beyond this century. The East Antarctic Ice Sheet (EAIS), which contains deep subglacial basins with reverse-sloping, is considered to be susceptible to ice loss caused by marine ice sheet instability. Sediment core offshore Wilkes Subglacial Basin reveals oscillations in the provenance of detrital sediment that have been interpreted to reflect an erosion of Wilkes Basin during interglacial periods MIS 5, MIS 7, and MIS 9 greater than Holocene period (Wilson et al., 2018). The aim of our study is to investigate past climate and environmental changes in the coastal area of the East Antarctic Ice Sheet during MIS 7.5 and 9.3 with the help of a new high-resolution water isotopes record of the TALDICE ice core.Here we present new δ18O and δD high resolution (5 cm) records covering the oldest portion of the TALDICE ice core. MIS 7.5 and 9.3 isotopic signal reveals a unique feature, already observed for MIS 5.5, that has not been spotted in other Antarctic ice cores (Masson-Delmotte et al., 2011). Interglacial periods at TALDICE are characterized by a first peak, observed in correspondence to the culmination of the deglaciation event as for all Antarctic cores, followed by a less pronounced isotopic peak (for MIS 5.5 and 9.3) or a plateau (for MIS 7.5) prior to the glacial inception. Several factors might drive this peculiar behavior of the water stable isotopes record, as an increase in temperatures due to a drop in surface elevation or changes in moisture sources.The new δ18O and δD high-resolution records for the TALDICE ice core reveal a unique pattern that characterizes interglacial periods at Talos Dome. Taking into account the coastal position of the core and its vicinity to the Wilkes Subglacial Basin we intend to investigate the possible decrease in surface elevation, through the application of the GRISLI ice sheet model (Quiquet et al., 2018), and changes in moisture sources, traceable from the d-excess record.
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- 2021
29. The GRISLI-LSCE contribution to the Ice Sheet Model Intercomparison Project for phase 6 of the Coupled Model Intercomparison Project (ISMIP6) – Part 1: Projections of the Greenland ice sheet evolution by the end of the 21st century
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Christophe Dumas, Aurélien Quiquet, 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), Modélisation du climat (CLIM), 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 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)
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010504 meteorology & atmospheric sciences ,Greenland ice sheet ,010502 geochemistry & geophysics ,01 natural sciences ,Glacier mass balance ,[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment ,lcsh:Environmental sciences ,Sea level ,ComputingMilieux_MISCELLANEOUS ,0105 earth and related environmental sciences ,Earth-Surface Processes ,Water Science and Technology ,lcsh:GE1-350 ,[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere ,geography ,Coupled model intercomparison project ,geography.geographical_feature_category ,lcsh:QE1-996.5 ,Global warming ,lcsh:Geology ,Ice-sheet model ,13. Climate action ,Climatology ,Polar amplification ,Ice sheet ,Geology - Abstract
Polar amplification will result in amplified temperature changes in the Arctic with respect to the rest of the globe, making the Greenland ice sheet particularly vulnerable to global warming. While the ice sheet has been showing an increased mass loss in the past decades, its contribution to global sea level rise in the future is of primary importance since it is at present the largest single-source contribution after the thermosteric contribution. The question of the fate of the Greenland and Antarctic ice sheets for the next century has recently gathered various ice sheet models in a common framework within the Ice Sheet Model Intercomparison Project for the Coupled Model Intercomparison Project – phase 6 (ISMIP6). While in a companion paper we present the GRISLI-LSCE (Grenoble Ice Sheet and Land Ice model of the Laboratoire des Sciences du Climat et de l'Environnement) contribution to ISMIP6-Antarctica, we present here the GRISLI-LSCE contribution to ISMIP6-Greenland. We show an important spread in the simulated Greenland ice loss in the future depending on the climate forcing used. The contribution of the ice sheet to global sea level rise in 2100 can thus be from as low as 20 mm sea level equivalent (SLE) to as high as 160 mm SLE. Amongst the models tested in ISMIP6, the Coupled Model Intercomparison Project – phase 6 (CMIP6) models produce larger ice sheet retreat than their CMIP5 counterparts. Low-emission scenarios in the future drastically reduce the ice mass loss. The oceanic forcing contributes to about 10 mm SLE in 2100 in our simulations. In addition, the dynamical contribution to ice thickness change is small compared to the impact of surface mass balance. This suggests that mass loss is mostly driven by atmospheric warming and associated ablation at the ice sheet margin. With additional sensitivity experiments we also show that the spread in mass loss is only weakly affected by the choice of the ice sheet model mechanical parameters.
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- 2021
30. Future Sea Level Change Under Coupled Model Intercomparison Project Phase 5 and Phase 6 Scenarios From the Greenland and Antarctic Ice Sheets
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Richard I. Cullather, Sainan Sun, Robin S. Smith, Martin Rückamp, Philippe Huybrechts, Thomas J. Bracegirdle, Christopher M. Little, Daniel P. Lowry, Fiammetta Straneo, Jonas Van Breedam, Xavier Fettweis, Nicolas C. Jourdain, Ricarda Winkelmann, Gunter R. Leguy, Isabel Nias, Erika Simon, Eric Larour, Sophie Nowicki, J. K. Cuzzone, Patrick Alexander, Cheng Zhao, Tore Hattermann, Heiko Goelzer, Christophe Dumas, Alice Barthel, Torsten Albrecht, Peter Kuipers Munneke, Helene Seroussi, Christopher Chambers, Andrew Shepherd, Frank Pattyn, Rupert Gladstone, Nicole Schlegel, Xylar Asay-Davis, Denis Felikson, Michiel R. van den Broeke, Mathieu Morlighem, Victoria Lee, Ayako Abe-Ouchi, Andy Aschwanden, Ralf Greve, Tamsin L. Edwards, Reinhard Calov, Thomas Kleiner, Donald Slater, Tong Zhang, Antony J. Payne, Benjamin K. Galton-Fenzi, Cécile Agosta, Luke D. Trusel, Lev Tarasov, Aurélien Quiquet, Nicholas R. Golledge, Youngmin Choi, William H. Lipscomb, Stephen Price, Angelika Humbert, Sébastien Le clec'h, Roderik S. W. van de Wal, Matthew J. Hoffman, Tyler Pelle, Jonathan M. Gregory, Thomas Zwinger, Ronja Reese, Earth System Sciences, Geography, Physical Geography, Marine and Atmospheric Research, Sub Dynamics Meteorology, Proceskunde, and Sub Algemeen Marine & Atmospheric Res
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010504 meteorology & atmospheric sciences ,Effects of global warming on oceans ,Greenland ,Antarctic ice sheet ,F700 ,Earth and Planetary Sciences(all) ,F800 ,sea level ,010502 geochemistry & geophysics ,7. Clean energy ,01 natural sciences ,Sea level ,0105 earth and related environmental sciences ,Coupled model intercomparison project ,geography ,geography.geographical_feature_category ,Future sea level ,ice sheet ,Ice-sheet model ,Geophysics ,13. Climate action ,Climatology ,General Earth and Planetary Sciences ,Environmental science ,Antarctica ,Climate model ,Ice sheet - Abstract
Projections of the sea level contribution from the Greenland and Antarctic ice sheets (GrIS and AIS) rely on atmospheric and oceanic drivers obtained from climate models. The Earth System Models participating in the Coupled Model Intercomparison Project phase 6 (CMIP6) generally project greater future warming compared with the previous Coupled Model Intercomparison Project phase 5 (CMIP5) effort. Here we use four CMIP6 models and a selection of CMIP5 models to force multiple ice sheet models as part of the Ice Sheet Model Intercomparison Project for CMIP6 (ISMIP6). We find that the projected sea level contribution at 2100 from the ice sheet model ensemble under the CMIP6 scenarios falls within the CMIP5 range for the Antarctic ice sheet but is significantly increased for Greenland. Warmer atmosphere in CMIP6 models results in higher Greenland mass loss due to surface melt. For Antarctica, CMIP6 forcing is similar to CMIP5 and mass gain from increased snowfall counteracts increased loss due to ocean warming.
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- 2021
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31. From the Climates of the Past to the Climates of the Future
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Gilles Ramstein, Laurent Bopp, Jean-Louis Dufresne, Julien Cattiaux, Nathaelle Bouttes, Aurélien Quiquet, Sylvie Charbit, Modélisation du climat (CLIM), 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)-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), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-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), 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), Gilles Ramstein, Amaëlle Landais, Nathaelle Bouttes, Pierre Sepulchre, Aline Govin, 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), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), and Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS)
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Geography ,010504 meteorology & atmospheric sciences ,[SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology ,13. Climate action ,business.industry ,Environmental resource management ,Future climate ,010502 geochemistry & geophysics ,business ,01 natural sciences ,Natural (archaeology) ,0105 earth and related environmental sciences - Abstract
International audience; This chapter connects everything we have learned about past climates (both from the analysis of natural archives and from numerical simulations), and future climate projections. The models used to explore the future are similar to those used for past climates, except that the results are based on emission scenarios of greenhouse gas emissions whereas past climate simulations may be compared to reconstructions from the natural archives described in volume 1. The climate of the past 1,000 years can be seen as the ‘background noise’ of the recent natural evolution of theclimate system. On this basis, the current climate change can be analyzed. Over the longer term, analysis of ice cores allows us to trace back the history of atmospheric CO2 concentration over the last 800,000 years, and shows that the anthropogenic disturbance (producing an atmospheric CO2 concentration currently in excess of 410 ppm) is completely outside the documented glacialinterglacial variations over the last million years, ranging from 180 to 280 ppm. With this awareness you are well equipped to now explore the climate of the future.
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- 2020
32. Response
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Aurélien Quiquet
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- 2020
33. The GRISLI-LSCE contribution to ISMIP6, Part 2: projections of the Antarctic ice sheet evolution by the end of the 21st century
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Aurélien Quiquet and Christophe Dumas
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Of primary societal importance, the ice sheet contribution to global sea level rise over the 21st century remains largely uncertain. In particular, the contribution of the Antarctic ice sheet by 2100 ranges from a few millimetres to more than one metre in the recent literature. The Ice Sheet Model Intercomparison Project for CMIP6 aimed at reducing the uncertainties on the fate of the ice sheets in the future by gathering various ice sheet models in a common framework. While in a companion paper we present the GRISLI-LSCE contribution to ISMIP6-Greenland, we present here the GRISLI-LSCE contribution to ISMIP6-Antarctica. We show that our model is strongly sensitive to the climate forcing used, with a contribution of the Antarctic ice sheet to global sea level rise by 2100 that ranges from −50 mm to +150 mm of sea level equivalent. Future oceanic warming leads to a decrease in thickness of the ice shelves and implies grounding line retreats while increased precipitation partially mitigates the ice sheet contribution to global sea level rise. Most of ice sheet changes over the next century are dampened under low greenhouse gas emission scenarios. Uncertainties related to sub-shelf basal melt induce large differences in simulated grounding line retreats, confirming the importance of this process and its representation in ice sheet models for the projections of the Antarctic ice sheet.
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- 2020
34. The GRISLI-LSCE contribution to ISMIP6, Part 1: projections of the Greenland ice sheet evolution by the end of the 21st century
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Aurélien Quiquet and Christophe Dumas
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geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Global warming ,Greenland ice sheet ,Forcing (mathematics) ,Radiative forcing ,010502 geochemistry & geophysics ,01 natural sciences ,The arctic ,Ice-sheet model ,Climatology ,Polar amplification ,Ice sheet ,Geology ,0105 earth and related environmental sciences - Abstract
Polar amplification will result in amplified temperature changes in the Arctic with respect to the rest of the globe making the Greenland ice sheet particularly vulnerable to global warming. While the ice sheet has been showing an increase mass loss in the past decades, its contribution to global sea level rise in the future is of primary importance since it is at present the largest single source contribution behind the thermosteric contribution. The question of the fate of the Greenland and Antarctic ice sheets for the next century has recently gathered various ice sheet models in a common framework within the Ice Sheet Model Intercomparison Project for CMIP6. While in a companion paper we present the GRISLI-LSCE contribution to ISMIP6-Antarctica, we present here the GRISLI-LSCE contribution to ISMIP6-Greenland. We show an important spread in the simulated Greenland ice loss in the future depending on the climate forcing used. The contribution of the ice sheet to global sea level rise in 2100 can be thus as low as 20 mmSLE to as high as 160 mmSLE. The CMIP6 models produce much larger ice sheet retreat than their CMIP5 counterparts. Low emission scenarios in the future drastically reduce the ice mass loss. The mass loss is mostly driven by atmospheric warming and associated ablation at the ice sheet margin while oceanic forcing contributes to about 10 mmSLE in 2100 in our simulations.
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- 2020
35. Global coupled climate - ice sheet model simulations for the penultimate deglaciation and the last interglacial
- Author
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Pepijn Johannes Bakker, Didier M. Roche, Bas de Boer, and Aurélien Quiquet
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Ice-sheet model ,Climatology ,Interglacial ,Deglaciation ,Geology - Abstract
Glacial-interglacial changes of the Earth's climate are largely controlled by internal mechanisms that drive changes in greenhouse gases and ice sheets. In this study, we present model experiments of the penultimate deglaciation into the the last interglacial period, obtained with the Earth system model of intermediate complexity iLOVECLIM (v. 1.1.4). We show experiments with an imposed ice-sheet scenario together with initial results with both North and South interactive ice sheets using the GRISLI (v. 2.0) 3-D ice-sheet model. To this aim, we use a recently developed dynamical downscaling procedure to compute temperature and precipitation fields from the relative low resolution atmospheric model grid (T21, ~5.6º) to the GRISLI spherical grids of both the Northern Hemisphere and Antarctica (both 40 x 40 km). We investigate the separate impact of variations of greenhouse gases (GHG), orbital parameters and ice sheets on glacial-interglacial climate change over the past 240 kyr. Using prescribed greenhouse gases or ice sheets induce comparable changes in global mean temperature. Greenhouse gases, predominantly CO2, mainly have a global impact through radiative forcing on atmospheric temperatures. On the other hand, ice sheets have a more regional impact over the Northern Hemispheric (NH) continents and Antarctica during glacial times. Henceforth, polar amplification is more pronounced during glacial periods following large ice-sheet induced changes. Overall these results are comparable to other studies using a similar experimental design. In order to initiate the coupling between the ice sheets and climate model, we perform a large ensemble of experiments to calibrate ice-sheet model parameters for the present day. We will present how the optimal settings for the two ice-sheet regions are selected, based on a comparison with the present-day ice sheets on Antarctica and Greenland. For the coupling, iLOVECLIM generates downscaled SMB, surface temperatures, ocean temperature and salinity, and GRISLI provides surface elevation and ice extent, the coupling interval is 5 years. These experiments are started during the penultimate glacial maximum. We initialize the coupled iLOVECLIM - GRISLI experiments from a climatic forcing experiment using prescribed greenhouse gases and ice sheets, and generate a spin-up simulation of GRISLI using the optimal settings for three different time points at 136, 135 and 134 kyr ago. Initial experiments show a clear linkage between changes in ice sheets, sea ice and ocean circulation. Following the forced rise in atmospheric GHGs, the magnitude of retreat varries between ice sheets, related to location and insolation change (which increases for the NH but decreased for Antarctica). Moreover, sea ice both decrease following GHGs increase, and vary more in phase with global mean temperature.
- Published
- 2020
36. The PMIP4-CMIP6 Last Glacial Maximum experiments: preliminary results and comparison with the PMIP3-CMIP5 simulations
- Author
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Aurélien Quiquet, Didier M. Roche, Gerrit Lohmann, Nathaelle Bouttes, Deepak Chandan, Evgeny Volodin, Uwe Mikolajewicz, Rumi Ohgaito, Sam Sherriff-Tadano, Tristan Vadsaria, Polina Morozova, Xiaoxu Shi, Andreas Schmittner, Marcus Lofverstrom, Marie-L. Kapsch, Jessica E. Tierney, Masa Kageyama, Fanny Lhardy, Sandy P. Harrison, W. Richard Peltier, Allegra N. LeGrande, Juan M. Lora, and Ayako Abe-Ouchi
- Subjects
010506 paleontology ,Coupled model intercomparison project ,Ocean current ,Climate change ,Last Glacial Maximum ,Jet stream ,01 natural sciences ,13. Climate action ,Climatology ,Paleoclimatology ,Polar amplification ,Environmental science ,Climate model ,Physical geography ,Precipitation ,Geology ,0105 earth and related environmental sciences - Abstract
The Last Glacial Maximum (LGM, ~ 21,000 years ago) has been a major focus for evaluating how well state-of-the-art climate models simulate climate changes as large as those expected in the future using paleoclimate reconstructions. A new generation of climate models have been used to generate LGM simulations as part of the Palaeoclimate Modelling Intercomparison Project (PMIP) contribution to the Coupled Model Intercomparison Project (CMIP). Here we provide a preliminary analysis and evaluation of the results of these LGM experiments (PMIP4-CMIP6) and compare them with the previous generation of simulations (PMIP3-CMIP5). We show that the PMIP4-CMIP6 are globally less cold and less dry than the PMIP3-CMIP5 simulations, most probably because of the use of a more realistic specification of the northern hemisphere ice sheets in the latest simulations although changes in model configuration may also contribute to this. There are important differences in both atmospheric and ocean circulation between the two sets of experiments, with the northern and southern jet streams being more poleward and the changes in the Atlantic Meridional Overturning Circulation being less pronounced in the PMIP4-CMIP6 simulations than in the PMIP3-CMIP5 simulations. Changes in simulated precipitation patterns are influenced by both temperature and circulation changes. Differences in simulated climate between individual models remain large so, although there are differences in the average behaviour across the two ensembles, the new simulation results are not fundamentally different from the PMIP3-CMIP5 results. Evaluation of large-scale climate features, such as land-sea contrast and polar amplification, confirms that the models capture these well and within the uncertainty of the palaeoclimate reconstructions. Nevertheless, regional climate changes are less well simulated: the models underestimate extratropical cooling, particularly in winter, and precipitation changes. The spatial patterns of increased precipitation associated with changes in the jet streams are also poorly captured. However, changes in the tropics are more realistic, particularly the changes in tropical temperatures over the oceans. Although these results are preliminary in nature, because of the limited number of LGM simulations currently available, they nevertheless point to the utility of using paleoclimate simulations to understand the mechanisms of climate change and evaluate model performance.
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- 2020
37. Modelling the impact of biogenic particle flux intensity and composition on sedimentary Pa/Th
- Author
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Katrin J. Meissner, Jean Claude Dutay, Laurie Menviel, Didier M. Roche, Claire Waelbroeck, Nathaelle Bouttes, Sylvain Pichat, Aurélien Quiquet, Lise Missiaen, Fanny Lhardy, Climate Change Research Centre, ARC Centre of Excellence for Climate System Science, University of New South Wales, Sydney 2052, Australia, University of New South Wales [Sydney] (UNSW), Mark Wainwright Analytical Centre [Sydney] (UNSW ), 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), Modélisation du climat (CLIM), 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 Louis Bachelier, Université Claude Bernard Lyon 1 (UCBL), Université de Lyon, Max Planck Institute for Chemistry (MPIC), Max-Planck-Gesellschaft, Processus et interactions de fine échelle océanique (PROTEO), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-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)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-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)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-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)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Australian Research Council, ARC: FT180100606, DP180100048, KJM, LCM and LM acknowledge funding from the Australian Research Council grant DP180100048 awarded to KJM and LCM and grant FT180100606 awarded to LCM., European Project: 339108,EC:FP7:ERC,ERC-2013-ADG,ACCLIMATE(2014), 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 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)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-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)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-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)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU), and Earth Sciences
- Subjects
010506 paleontology ,Archeology ,010504 meteorology & atmospheric sciences ,[SDE.MCG]Environmental Sciences/Global Changes ,01 natural sciences ,Ocean circulation ,Glacial period ,Stadial ,SDG 14 - Life Below Water ,Particle flux ,Scavenging ,Ecology, Evolution, Behavior and Systematics ,0105 earth and related environmental sciences ,Global and Planetary Change ,Atlantic hurricane ,Particle fluxes ,North Atlantic Deep Water ,Ocean current ,iLOVECLIM ,Geology ,Pa/Th ,Oceanography ,13. Climate action ,Abrupt climate events ,Environmental science ,Sedimentary rock - Abstract
There is compelling evidence of a strong relation between the Atlantic Meridional Overturning Circulation (AMOC) and millennial scale climate variability during the last glacial period. Part of the advances in understanding the underlying mechanisms rely on the analysis of the sedimentary Pa/Th ratio, which can be used to qualitatively infer past flow rates in the Atlantic. The compilation of existing North Atlantic records indicates repeated, consistent and significant Pa/Th increases across millennial-scale events, indicating significant reductions of deep-water formation in the Northwest Atlantic. However, the use of sedimentary Pa/Th as a pure kinematic circulation proxy is challenging because Pa and Th are also highly sensitive to changes in particulate flux intensity and composition that have probably occurred across these millennial scale events. A primary control of particles on the available Pa/Th records has been ruled out ensuring the absence of correlation between the reconstructed particle fluxes (e.g. Th-normalized opal fluxes) and the sedimentary Pa/Th. However, quantitative estimates of the impact of particles on the available paleo Pa/Th are still missing.In this study, we use the Pa/Th enabled iLOVECLIM Earth System Model of Intermediate Complexity to decipher the impact of particles on the sedimentary Pa/Th. We evaluate the impact of imposed changes in biogenic particle flux intensity and composition on the Atlantic Pa/Th in a 3-D geographical perspective. We find that up to 30% of the observed Pa/Th increase across Heinrich Stadial 1 could be explained by changes in particle fluxes and composition. Besides, changes in the Particulate Organic Carbon (POC) most efficiently affects the sedimentary Pa/Th, followed by biogenic opal. Last but not least, the global Atlantic sedimentary Pa/Th response is very sensitive to shifts in the geographical distribution of particles and high scavenging areas. In our simulations, a decrease of the opal production in the Northwest Atlantic can induce a far field Pa/Th increase in a large part of the North Atlantic basin, suggesting that a local monitoring of the particle fluxes might not be enough to rule out any influence of the particles on paleo sedimentary Pa/Th records.
- Published
- 2020
38. Polar amplification of Pliocene climate by elevated trace gas radiative forcing
- Author
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Aurélien Quiquet, Thomas A. M. Pugh, Fabiola Murguia-Flores, Ning Tan, Paul J. Valdes, Yong Sun, Gilles Ramstein, Peter O. Hopcroft, Stephen J. Hunter, School of Geography, Earth and Environmental Sciences [Birmingham], University of Birmingham [Birmingham], 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), Modélisation du climat (CLIM), 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), School of Geography [Leeds], University of Leeds, School of Geographical Sciences [Bristol], University of Bristol [Bristol], ANR-17-CE31-0010,HADoC,Rôle du Climat dans la dispersion des ancêtres de l'Homme(2017), 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
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere ,Multidisciplinary ,010504 meteorology & atmospheric sciences ,Biogeochemistry ,Forcing (mathematics) ,15. Life on land ,Radiative forcing ,010502 geochemistry & geophysics ,Atmospheric sciences ,01 natural sciences ,Trace gas ,13. Climate action ,Physical Sciences ,Polar amplification ,Pliocene climate ,Climate sensitivity ,Environmental science ,Climate model ,[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment ,0105 earth and related environmental sciences - Abstract
Warm periods in Earth’s history offer opportunities to understand the dynamics of the Earth system under conditions that are similar to those expected in the near future. The Middle Pliocene warm period (MPWP), from 3.3 to 3.0 My B.P, is the most recent time when atmospheric CO(2) levels were as high as today. However, climate model simulations of the Pliocene underestimate high-latitude warming that has been reconstructed from fossil pollen samples and other geological archives. One possible reason for this is that enhanced non-CO(2) trace gas radiative forcing during the Pliocene, including from methane (CH(4)), has not been included in modeling. We use a suite of terrestrial biogeochemistry models forced with MPWP climate model simulations from four different climate models to produce a comprehensive reconstruction of the MPWP CH(4) cycle, including uncertainty. We simulate an atmospheric CH(4) mixing ratio of 1,000 to 1,200 ppbv, which in combination with estimates of radiative forcing from N(2)O and O(3), contributes a non-CO(2) radiative forcing of 0.9 [Formula: see text] (range 0.6 to 1.1), which is 43% (range 36 to 56%) of the CO(2) radiative forcing used in MPWP climate simulations. This additional forcing would cause a global surface temperature increase of 0.6 to 1.0 °C, with amplified changes at high latitudes, improving agreement with geological evidence of Middle Pliocene climate. We conclude that natural trace gas feedbacks are critical for interpreting climate warmth during the Pliocene and potentially many other warm phases of the Cenezoic. These results also imply that using Pliocene CO(2) and temperature reconstructions alone may lead to overestimates of the fast or Charney climate sensitivity.
- Published
- 2020
39. Online dynamical downscaling of temperature and precipitation within the iLOVECLIM model (version 1.1)
- Author
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Didier Paillard, Christophe Dumas, Didier M. Roche, and Aurélien Quiquet
- Subjects
010504 meteorology & atmospheric sciences ,Meteorology ,Atmospheric model ,010502 geochemistry & geophysics ,Grid ,01 natural sciences ,Regular grid ,Ice-sheet model ,13. Climate action ,Climatology ,Environmental science ,Climate model ,Precipitation ,0105 earth and related environmental sciences ,Downscaling ,Standard model (cryptography) - Abstract
This paper presents the inclusion of an online dynamical downscaling of temperature and precipitation within the model of intermediate complexity iLOVECLIM v1.1. We describe the following methodology to generate temperature and precipitation fields on a 40 km × 40 km Cartesian grid of the Northern Hemisphere from the T21 native atmospheric model grid. Our scheme is not grid specific and conserves energy and moisture in the same way as the original climate model. We show that we are able to generate a high-resolution field which presents a spatial variability in better agreement with the observations compared to the standard model. Although the large-scale model biases are not corrected, for selected model parameters, the downscaling can induce a better overall performance compared to the standard version on both the high-resolution grid and on the native grid. Foreseen applications of this new model feature include the improvement of ice sheet model coupling and high-resolution land surface models.
- Published
- 2018
40. Online dynamical downscaling of temperature and precipitation within the iLOVECLIM model (version 1.1)
- Author
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Aurélien Quiquet, Didier M. Roche, Christophe Dumas, Didier Paillard, Earth and Climate, 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), Modélisation du climat (CLIM), 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 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 ,010504 meteorology & atmospheric sciences ,SDG 13 - Climate Action ,010502 geochemistry & geophysics ,[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment ,01 natural sciences ,Physics::Atmospheric and Oceanic Physics ,0105 earth and related environmental sciences - Abstract
International audience; This paper presents the inclusion of an online dy-namical downscaling of temperature and precipitation within the model of intermediate complexity iLOVECLIM v1.1. We describe the following methodology to generate temperature and precipitation fields on a 40 km × 40 km Cartesian grid of the Northern Hemisphere from the T21 native atmospheric model grid. Our scheme is not grid specific and conserves energy and moisture in the same way as the original climate model. We show that we are able to generate a high-resolution field which presents a spatial variability in better agreement with the observations compared to the standard model. Although the large-scale model biases are not corrected , for selected model parameters, the downscaling can induce a better overall performance compared to the standard version on both the high-resolution grid and on the native grid. Foreseen applications of this new model feature include the improvement of ice sheet model coupling and high-resolution land surface models.
- Published
- 2018
41. Supplementary material to 'Carbon isotopes and Pa / Th response to forced circulation changes: a model perspective'
- Author
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Lise Missiaen, Nathaelle Bouttes, Didier M. Roche, Jean-Claude Dutay, Aurélien Quiquet, Claire Waelbroeck, Sylvain Pichat, and Jean-Yves Peterschmitt
- Published
- 2019
42. Insolation threshold as a trigger of abrupt oscillations in AMOC at the end of interglacials
- Author
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Yin, Qiuzhen, Wu, Zhipeng, David A Hodel, Aurélien Quiquet, Berger, André, Goosse, Hugues, Gilles Ramstein, UCL - SST/ELI/ELIC - Earth & Climate, and UCL - SC/PHYS - Département de physique
- Abstract
Paleoclimate records show that abrupt climate changes have occurred frequently in the past. Glacial inceptions, marking the end of interglacial periods, are always marked by sudden cooling events and increased millennial variability. The mechanisms responsible for these abrupt changes are uncertain, and are usually ascribed to interactions between atmosphere, ocean and ice sheets. The role of external forcing by changes in Earth’s orbit is untested. We conducted LOVECLIM transient climate simulations for interglacials of the last 800,000 years, and found that there exists a threshold in insolation that can trigger abrupt oscillations in the Atlantic meridional overturning circulation (AMOC) via sea ice-temperature feedbacks in the northern North Atlantic as well as atmospheric and oceanic teleconnections. This, in turn, leads to abrupt oscillations in other components of the climate system such as temperature, precipitation and vegetation at global scale. In particular, it causes abrupt and nearly anti-phased climate variability in Northern and Southern Hemispheres on centennial-millennial time scales. Our simulated results are supported by observations from ice and marine sediment cores. The proposed insolation threshold occurred repeatedly in the past especially at the end of interglacials, suggesting its fundamental role in ending interglacial conditions and initiating glacial inceptions. Using an ice sheet model, we further investigate the response and feedbacks of the Northern Hemisphere continental ice sheets to the abrupt climate oscillations.
- Published
- 2019
43. Assessment of the Greenland ice sheet–atmosphere feedbacks for the next century with a regional atmospheric model coupled to an ice sheet model
- Author
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Xavier Fettweis, Christophe Dumas, Sébastien Le clec'h, Coraline Wyard, Catherine Ritz, Aurélien Quiquet, Masa Kageyama, Sylvie Charbit, 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), 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), Département de Géographie, Université de Liège, 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), Earth System Science Group [Brussels] (ESSc), Vrije Universiteit Brussel (VUB), Modélisation du climat (CLIM), 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]), Geography, Physical Geography, Earth System Sciences, 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), and 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])
- Subjects
Katabatic wind ,010504 meteorology & atmospheric sciences ,Greenland ice sheet ,Atmospheric model ,010502 geochemistry & geophysics ,01 natural sciences ,[SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology ,lcsh:Environmental sciences ,ComputingMilieux_MISCELLANEOUS ,0105 earth and related environmental sciences ,Earth-Surface Processes ,Water Science and Technology ,lcsh:GE1-350 ,geography ,geography.geographical_feature_category ,lcsh:QE1-996.5 ,Global warming ,Snow ,lcsh:Geology ,Ice-sheet model ,13. Climate action ,[SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology ,Climatology ,Sea ice thickness ,Ice sheet ,Geology - Abstract
International audience; In the context of global warming, growing attention is paid to the evolution of the Greenland ice sheet (GrIS) and its contribution to sea-level rise at the centennial timescale. Atmosphere-GrIS interactions, such as the temperature-elevation and the albedo feedbacks, have the potential to modify the surface energy balance and thus to impact the GrIS surface mass balance (SMB). In turn, changes in the geometrical features of the ice sheet may alter both the climate and the ice dynamics governing the ice sheet evolution. However, changes in ice sheet geometry are generally not explicitly accounted for when simulating atmospheric changes over the Greenland ice sheet in the future. To account for ice sheet-climate interactions, we developed the first two-way synchronously coupled model between a regional atmospheric model (MAR) and a 3-D ice sheet model (GRISLI). Using this novel model, we simulate the ice sheet evolution from 2000 to 2150 under a prolonged representative concentration pathway scenario, RCP8.5. Changes in surface elevation and ice sheet extent simulated by GRISLI have a direct impact on the climate simulated by MAR. They are fed to MAR from 2020 onwards, i.e. when changes in SMB produce significant topography changes in GRISLI. We further assess the importance of the atmosphere-ice sheet feedbacks through the comparison of the two-way coupled experiment with two other simulations based on simpler coupling strategies: (i) a one-way coupling with no consideration of any change in ice sheet geometry; (ii) an alternative one-way coupling in which the elevation change feedbacks are parameterized in the ice sheet model (from 2020 onwards) without taking into account the changes in ice sheet topography in the atmospheric model. The two-way coupled experiment simulates an important increase in surface melt below 2000 m of elevation, resulting in an important SMB reduction in 2150 and a shift of the equilibrium line towards elevations as high as 2500 m, despite a slight increase in SMB over the central plateau due to enhanced snowfall. In relation with these SMB changes, modifications of ice sheet geometry favour ice flux convergence towards the margins, with an increase in ice velocities in the GrIS interior due to increased surface slopes and a decrease in ice velocities at the margins due to decreasing ice thickness. This convergence counteracts the SMB signal in these areas. In the two-way coupling, the SMB is also influenced by changes in fine-scale atmospheric dynamical processes, such as the increase in katabatic winds from central to marginal regions induced by increased surface slopes. Altogether, the GrIS contribution to sea-level rise, inferred from variations in ice volume above floatation, is equal to 20.4 cm in 2150. The comparison between the coupled and the two uncoupled experiments suggests that the effect of the different feedbacks is amplified over time with the most important feedbacks being the SMB-elevation feedbacks. As a result, the experiment with parameterized SMB-elevation feedback provides a sea-level contribution from GrIS in 2150 only 2.5 % lower than the Published by Copernicus Publications on behalf of the European Geosciences Union. 374 S. Le clec'h et al.: Assessment of the Greenland ice sheet two-way coupled experiment, while the experiment with no feedback is 9.3 % lower. The change in the ablation area in the two-way coupled experiment is much larger than those provided by the two simplest methods, with an underestimation of 11.7 % (14 %) with parameterized feedbacks (no feedback). In addition, we quantify that computing the GrIS contribution to sea-level rise from SMB changes only over a fixed ice sheet mask leads to an overestimation of ice loss of at least 6 % compared to the use of a time variable ice sheet mask. Finally, our results suggest that ice-loss estimations diverge when using the different coupling strategies, with differences from the two-way method becoming significant at the end of the 21st century. In particular, even if averaged over the whole GrIS the climatic and ice sheet fields are relatively similar; at the local and regional scale there are important differences, highlighting the importance of correctly representing the interactions when interested in basin scale changes.
- Published
- 2019
44. Retrieval of the Absorption Coefficient of L-Band Radiation in Antarctica From SMOS Observations
- Author
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Catherine Ritz, Olivier Passalacqua, Fanny Larue, Marion Leduc-Leballeur, Aurélien Quiquet, Giovanni Macelloni, Ghislain Picard, 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 (UGA), EDGe, 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)-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), Institute of Applied Physics 'Nello Carrara' (IFAC), Consiglio Nazionale delle Ricerche (CNR), 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), 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]), 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 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), Modélisation du climat (CLIM), 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 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]), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), 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
Brightness ,brightness temperature ,010504 meteorology & atmospheric sciences ,Astrophysics::High Energy Astrophysical Phenomena ,0211 other engineering and technologies ,02 engineering and technology ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Band L ,01 natural sciences ,absorption coefficient ,Emissivity ,Sastrugi ,[SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology ,Absorption (electromagnetic radiation) ,lcsh:Science ,Astrophysics::Galaxy Astrophysics ,ComputingMilieux_MISCELLANEOUS ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences ,Remote sensing ,geography ,Radiometer ,geography.geographical_feature_category ,Firn ,permittivity ,13. Climate action ,Brightness temperature ,emissivity ,General Earth and Planetary Sciences ,Antarctica ,lcsh:Q ,Ice sheet ,Geology ,passive microwave ,SMOS - Abstract
Microwave emissions at the L-band (1&ndash, 2 GHz) in Antarctica are characterized by a significant contribution of ice layers at great depth, from hundreds to a thousand meters. Brightness temperatures, thus, could provide the internal temperature of the ice sheet. However, there are two difficulties to overcome in developing an accurate retrieval algorithm. First, it is difficult to know precisely from which depths waves are emanating because the ice-absorption coefficient is uncertain at the L-band, despite several formulations proposed in the literature over the past few decades. Second, emissivity potentially varies in Antarctica due to remnant scattering in firn (or ice), even at the Brewster angle, and despite the low frequency, limiting the accuracy of the estimate of the physical temperature. Here, we present a retrieval method able to disentangle the absorption and emissivity effects from brightness temperature over the whole continent. We exploit the fact that scattering and absorption are controlled by different physical parameters and phenomena that can be considered as statistically independent. This independence provides a constraint to the retrieval method, that is then well-conditioned and solvable. Our results show that (1) the retrieved absorption agrees with the permittivity model proposed by Mä, tzler et al. (2006), and (2) emissivity shows significant variations, up to 6% over the continent, which are correlated with wind speed and accumulation patterns. A possible cause of this latter point is density heterogeneity and sastrugi buried in the firn. These two results are an important step forward for the accurate retrieval of internal temperature using low-frequency microwave radiometers.
- Published
- 2018
45. An East Siberian ice shelf during the Late Pleistocene glaciations: Numerical reconstructions
- Author
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Aurélien Quiquet, Johan Liakka, Nina Kirchner, Frank Niessen, and Florence Colleoni
- Subjects
010506 paleontology ,Archeology ,Global and Planetary Change ,geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Ice stream ,Geology ,Antarctic sea ice ,01 natural sciences ,Arctic ice pack ,Iceberg ,Ice shelf ,Paleontology ,Oceanography ,Fast ice ,13. Climate action ,Sea ice ,Ice sheet ,Ecology, Evolution, Behavior and Systematics ,0105 earth and related environmental sciences - Abstract
A recent data campaign in the East Siberian Sea has revealed evidence of grounded and floating ice dynamics in regions of up to 1000 m water depth, and which are attributed to glaciations older than the Last Glacial Maximum (21 kyrs BP). The main hypothesis based on this evidence is that a small ice cap developed over Beringia and expanded over the East Siberian continental margin during some of the Late Pleistocene glaciations. Other similar evidence of ice dynamics that have been previously collected on the shallow continental shelves of the Arctic Ocean have been attributed to the penultimate glaciation, i.e. Marine Isotopes Stage 6 (≈140 kyrs BP). We use an ice sheet model, forced by two previously simulated MIS 6 glacial maximum climates, to carry out a series of sensitivity experiments testing the impact of dynamics and mass-balance related parameters on the geometry of the East Siberian ice cap and ice shelf. Results show that the ice cap developing over Beringia connects to the Eurasian ice sheet in all simulations and that its volume ranges between 6 and 14 m SLE, depending on the climate forcing. This ice cap generates an ice shelf of dimensions comparable with or larger than the present-day Ross ice shelf in West Antarctica. Although the ice shelf extent strongly depends on the ice flux through the grounding line, it is particularly sensitive to the choice of the calving and basal melting parameters. Finally, inhibiting a merging of the Beringia ice cap with the Eurasian ice sheet affects the expansion of the ice shelf only in the simulations where the ice cap fluxes are not large enough to compensate for the fluxes coming from the Eurasian ice sheet.
- Published
- 2016
46. Response to referee #1
- Author
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Aurélien Quiquet
- Published
- 2018
47. Response to referee #3
- Author
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Aurélien Quiquet
- Published
- 2018
48. Response to Fuyuki SAITO
- Author
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Aurélien Quiquet
- Published
- 2018
49. A rapidly converging spin-up method for the present-day Greenland ice sheet using the GRISLI ice-sheet model
- Author
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Aurélien Quiquet, Sébastien Le clec'h, Christophe Dumas, Masa Kageyama, Sylvie Charbit, and Catherine Ritz
- Subjects
geography ,Drag coefficient ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Scale (ratio) ,Ice stream ,Greenland ice sheet ,Mechanics ,010502 geochemistry & geophysics ,01 natural sciences ,Physics::Geophysics ,Ice-sheet model ,Drag ,Astrophysics::Earth and Planetary Astrophysics ,Spin-up ,Ice sheet ,Physics::Atmospheric and Oceanic Physics ,Geology ,0105 earth and related environmental sciences - Abstract
Providing reliable projections of the ice-sheet contribution to future sea-level rise has become one of the main challenges of the ice-sheet modelling community. To increase confidence in future projections, a good knowledge of the present-day state of the ice flow dynamics, which is critically dependent on basal conditions, is strongly needed. The main difficulty is tied to the scarcity of observations at the ice-bed interface at the scale of the whole ice sheet, resulting in poorly constrained parameterisations in ice-sheet models. To circumvent this drawback, inverse modelling approaches can be developed and validated against available data to infer reliable initial conditions of the ice sheet. Here, we present a spin-up method for the Greenland ice sheet using the thermo-mechanical hybrid GRISLI ice-sheet model. Our approach is based on the adjustment of the basal drag coefficient that relates the sliding velocities at the ice-bed interface to basal shear stress in unfrozen bed areas. This method relies on an iterative process in which the basal drag is periodically adjusted in such as way that the simulated ice thickness matches the observed one. The process depends on three parameters controlling the duration and the number of iterations. The best spin-up parameters are chosen according to two criteria to minimize errors in sea-level projections: the final difference between the simulated and the observed Greenland ice volume as well as the final ice volume trend which must both be as low as possible. To increase confidence in the inferred parameters, we also make sure that the final ice thickness root mean square error from the observations is not greater than a few tens of meters. Our best results are obtained after only 420 years of simulation, highlighting a rapid convergence and demonstrating that our method can be used for computationally expensive ice sheet models.
- Published
- 2018
50. Reply to Referee #1
- Author
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Aurélien Quiquet
- Published
- 2017
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