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2. Projected land ice contributions to twenty-first-century sea level rise

Author

Edwards, Tamsin L, Nowicki, Sophie, Marzeion, Ben, Hock, Regine, Goelzer, Heiko, Seroussi, Hélène, Jourdain, Nicolas C, Slater, Donald A, Turner, Fiona E, Smith, Christopher J, McKenna, Christine M, Simon, Erika, Abe-Ouchi, Ayako, Gregory, Jonathan M, Larour, Eric, Lipscomb, William H, Payne, Antony J, Shepherd, Andrew, Agosta, Cécile, Alexander, Patrick, Albrecht, Torsten, Anderson, Brian, Asay-Davis, Xylar, Aschwanden, Andy, Barthel, Alice, Bliss, Andrew, Calov, Reinhard, Chambers, Christopher, Champollion, Nicolas, Choi, Youngmin, Cullather, Richard, Cuzzone, Joshua, Dumas, Christophe, Felikson, Denis, Fettweis, Xavier, Fujita, Koji, Galton-Fenzi, Benjamin K, Gladstone, Rupert, Golledge, Nicholas R, Greve, Ralf, Hattermann, Tore, Hoffman, Matthew J, Humbert, Angelika, Huss, Matthias, Huybrechts, Philippe, Immerzeel, Walter, Kleiner, Thomas, Kraaijenbrink, Philip, Le clec’h, Sébastien, Lee, Victoria, Leguy, Gunter R, Little, Christopher M, Lowry, Daniel P, Malles, Jan-Hendrik, Martin, Daniel F, Maussion, Fabien, Morlighem, Mathieu, O’Neill, James F, Nias, Isabel, Pattyn, Frank, Pelle, Tyler, Price, Stephen F, Quiquet, Aurélien, Radić, Valentina, Reese, Ronja, Rounce, David R, Rückamp, Martin, Sakai, Akiko, Shafer, Courtney, Schlegel, Nicole-Jeanne, Shannon, Sarah, Smith, Robin S, Straneo, Fiammetta, Sun, Sainan, Tarasov, Lev, Trusel, Luke D, Van Breedam, Jonas, van de Wal, Roderik, van den Broeke, Michiel, Winkelmann, Ricarda, Zekollari, Harry, Zhao, Chen, Zhang, Tong, and Zwinger, Thomas

Subjects
Earth Sciences, Physical Geography and Environmental Geoscience, Climate Action, General Science & Technology
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 models2-8, 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.

Published
2021

3. Antarctic ice sheet response to sudden and sustained ice-shelf collapse (ABUMIP)

Author

Sun, Sainan, Pattyn, Frank, Simon, Erika G, Albrecht, Torsten, Cornford, Stephen, Calov, Reinhard, Dumas, Christophe, Gillet-Chaulet, Fabien, Goelzer, Heiko, Golledge, Nicholas R, Greve, Ralf, Hoffman, Matthew J, Humbert, Angelika, Kazmierczak, Elise, Kleiner, Thomas, Leguy, Gunter R, Lipscomb, William H, Martin, Daniel, Morlighem, Mathieu, Nowicki, Sophie, Pollard, David, Price, Stephen, Quiquet, Aurélien, Seroussi, Hélène, Schlemm, Tanja, Sutter, Johannes, van de Wal, Roderik SW, Winkelmann, Ricarda, and Zhang, Tong

Subjects
Earth Sciences, Physical Geography and Environmental Geoscience, Geology, Climate Action, Antarctic glaciology, ice-sheet modelling, ice shelves, Meteorology & Atmospheric Sciences, Physical geography and environmental geoscience
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.

Published
2020

4. Projecting Antarctica's contribution to future sea level rise from basal ice shelf melt using linear response functions of 16 ice sheet models (LARMIP-2)

Author

Levermann, Anders, Winkelmann, Ricarda, Albrecht, Torsten, Goelzer, Heiko, Golledge, Nicholas R, Greve, Ralf, Huybrechts, Philippe, Jordan, Jim, Leguy, Gunter, Martin, Daniel, Morlighem, Mathieu, Pattyn, Frank, Pollard, David, Quiquet, Aurelien, Rodehacke, Christian, Seroussi, Helene, Sutter, Johannes, Zhang, Tong, Van Breedam, Jonas, Calov, Reinhard, DeConto, Robert, Dumas, Christophe, Garbe, Julius, Gudmundsson, G Hilmar, Hoffman, Matthew J, Humbert, Angelika, Kleiner, Thomas, Lipscomb, William H, Meinshausen, Malte, Ng, Esmond, Nowicki, Sophie MJ, Perego, Mauro, Price, Stephen F, Saito, Fuyuki, Schlegel, Nicole-Jeanne, Sun, Sainan, and van de Wal, Roderik SW

Subjects
Earth Sciences, Oceanography, Physical Geography and Environmental Geoscience, Geology, Climate Action, Atmospheric Sciences, Climate change science, Geoinformatics
Abstract

The sea level contribution of the Antarctic ice sheet constitutes a large uncertainty in future sea level projections. Here we apply a linear response theory approach to 16 state-of-the-art ice sheet models to estimate the Antarctic ice sheet contribution from basal ice shelf melting within the 21st century. The purpose of this computation is to estimate the uncertainty of Antarctica's future contribution to global sea level rise that arises from large uncertainty in the oceanic forcing and the associated ice shelf melting. Ice shelf melting is considered to be a major if not the largest perturbation of the ice sheet's flow into the ocean. However, by computing only the sea level contribution in response to ice shelf melting, our study is neglecting a number of processes such as surface-mass-balance-related contributions. In assuming linear response theory, we are able to capture complex temporal responses of the ice sheets, but we neglect any self-dampening or self-amplifying processes. This is particularly relevant in situations in which an instability is dominating the ice loss. The results obtained here are thus relevant, in particular wherever the ice loss is dominated by the forcing as opposed to an internal instability, for example in strong ocean warming scenarios. In order to allow for comparison the methodology was chosen to be exactly the same as in an earlier study (Levermann et al., 2014) but with 16 instead of 5 ice sheet models. We include uncertainty in the atmospheric warming response to carbon emissions (full range of CMIP5 climate model sensitivities), uncertainty in the oceanic transport to the Southern Ocean (obtained from the time-delayed and scaled oceanic subsurface warming in CMIP5 models in relation to the global mean surface warming), and the observed range of responses of basal ice shelf melting to oceanic warming outside the ice shelf cavity. This uncertainty in basal ice shelf melting is then convoluted with the linear response functions of each of the 16 ice sheet models to obtain the ice flow response to the individual global warming path. The model median for the observational period from 1992 to 2017 of the ice loss due to basal ice shelf melting is 10.2 mm, with a likely range between 5.2 and 21.3 mm. For the same period the Antarctic ice sheet lost mass equivalent to 7.4mm of global sea level rise, with a standard deviation of 3.7mm (Shepherd et al., 2018) including all processes, especially surface-mass-balance changes. For the unabated warming path, Representative Concentration Pathway 8.5 (RCP8.5), we obtain a median contribution of the Antarctic ice sheet to global mean sea level rise from basal ice shelf melting within the 21st century of 17 cm, with a likely range (66th percentile around the mean) between 9 and 36 cm and a very likely range (90th percentile around the mean) between 6 and 58 cm. For the RCP2.6 warming path, which will keep the global mean temperature below 2 °C of global warming and is thus consistent with the Paris Climate Agreement, the procedure yields a median of 13 cm of global mean sea level contribution. The likely range for the RCP2.6 scenario is between 7 and 24 cm, and the very likely range is between 4 and 37 cm. The structural uncertainties in the method do not allow for an interpretation of any higher uncertainty percentiles.We provide projections for the five Antarctic regions and for each model and each scenario separately. The rate of sea level contribution is highest under the RCP8.5 scenario. The maximum within the 21st century of the median value is 4 cm per decade, with a likely range between 2 and 9 cm per decade and a very likely range between 1 and 14 cm per decade.

Published
2020

6. New avenues for potentially seeking microbial responses to climate change beneath Antarctic ice shelves

Author

Universidad de Alicante. Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante. Instituto Multidisciplinar para el Estudio del Medio "Ramón Margalef", Llorenç-Vicedo, Aitana, Lluesma Gómez, Mónica, Zeising, Ole, Kleiner, Thomas, Freitag, Johannes, Martinez-Hernandez, Francisco, Wilhelms, Frank, Martinez-Garcia, Manuel, Universidad de Alicante. Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante. Instituto Multidisciplinar para el Estudio del Medio "Ramón Margalef", Llorenç-Vicedo, Aitana, Lluesma Gómez, Mónica, Zeising, Ole, Kleiner, Thomas, Freitag, Johannes, Martinez-Hernandez, Francisco, Wilhelms, Frank, and Martinez-Garcia, Manuel

Abstract

The signs of climate change are undeniable, and the impact of these changes on ecosystem function heavily depends on the response of microbes that underpin the food web. Antarctic ice shelf is a massive mass of floating ice that extends from the continent into the ocean, exerting a profound influence on global carbon cycles. Beneath Antarctic ice shelves, marine ice stores valuable genetic information, where marine microbial communities before the industrial revolution are archived. Here, in this proof-of-concept, by employing a combination of single-cell technologiesand metagenomics, we have been able to sequence frozen microbial DNA (≈300 years old) stored in the marine ice core B15 collected from the Filchnner-Ronne Ice Shelf. Metagenomic data indicated that Proteobacteria and Thaumarchaeota (e.g., Nitrosopumilus spp.), followed by Actinobacteria (e.g., Actinomarinales), were abundant. Remarkably, our data allow us to “travel to the past” and calibrate genomic and genetic evolutionary changes for ecologically relevant microbes and functions, such as Nitrosopumilus spp., preserved in the marine ice (≈300 years old) with those collected recently in seawater under an ice shelf (year 2017). The evolutionary divergence for the ammonia monooxygenase gene amoA involved in chemolithoautotrophy was about 0.88 amino acid and 2.8 nucleotide substitution rate per 100 sites in a century, while the accumulated rate of genomic SNPs was 2,467 per 1 Mb of genome and 100 years. Whether these evolutionary changes remained constant over the last 300 years or accelerated during post-industrial periods remains an open question that will be further elucidated.

Published
2024

7. Modelling calving front dynamics using a level-set method: application to Jakobshavn Isbræ, West Greenland

Author

Bondzio, Johannes H, Seroussi, Hélène, Morlighem, Mathieu, Kleiner, Thomas, Rückamp, Martin, Humbert, Angelika, and Larour, Eric Y

Subjects
Earth Sciences, Physical Geography and Environmental Geoscience, Climate Action, Oceanography, Meteorology & Atmospheric Sciences, Physical geography and environmental geoscience
Abstract

Calving is a major mechanism of ice discharge of the Antarctic and Greenland ice sheets, and a change in calving front position affects the entire stress regime of marine terminating glaciers. The representation of calving front dynamics in a 2-D or 3-D ice sheet model remains non-trivial. Here, we present the theoretical and technical framework for a level-set method, an implicit boundary tracking scheme, which we implement into the Ice Sheet System Model (ISSM). This scheme allows us to study the dynamic response of a drainage basin to user-defined calving rates. We apply the method to Jakobshavn Isbræ, a major marine terminating outlet glacier of the West Greenland Ice Sheet. The model robustly reproduces the high sensitivity of the glacier to calving, and we find that enhanced calving triggers significant acceleration of the ice stream. Upstream acceleration is sustained through a combination of mechanisms. However, both lateral stress and ice influx stabilize the ice stream. This study provides new insights into the ongoing changes occurring at Jakobshavn Isbræ and emphasizes that the incorporation of moving boundaries and dynamic lateral effects, not captured in flow-line models, is key for realistic model projections of sea level rise on centennial timescales.

Published
2016

9. Insights into the vulnerability of Antarctic glaciers from the ISMIP6 ice sheet model ensemble and associated uncertainty

Author

Seroussi, Hélène, primary, Verjans, Vincent, additional, Nowicki, Sophie, additional, Payne, Antony J., additional, Goelzer, Heiko, additional, Lipscomb, William H., additional, Abe-Ouchi, Ayako, additional, Agosta, Cécile, additional, Albrecht, Torsten, additional, Asay-Davis, Xylar, additional, Barthel, Alice, additional, Calov, Reinhard, additional, Cullather, Richard, additional, Dumas, Christophe, additional, Galton-Fenzi, Benjamin K., additional, Gladstone, Rupert, additional, Golledge, Nicholas R., additional, Gregory, Jonathan M., additional, Greve, Ralf, additional, Hattermann, Tore, additional, Hoffman, Matthew J., additional, Humbert, Angelika, additional, Huybrechts, Philippe, additional, Jourdain, Nicolas C., additional, Kleiner, Thomas, additional, Larour, Eric, additional, Leguy, Gunter R., additional, Lowry, Daniel P., additional, Little, Chistopher M., additional, Morlighem, Mathieu, additional, Pattyn, Frank, additional, Pelle, Tyler, additional, Price, Stephen F., additional, Quiquet, Aurélien, additional, Reese, Ronja, additional, Schlegel, Nicole-Jeanne, additional, Shepherd, Andrew, additional, Simon, Erika, additional, Smith, Robin S., additional, Straneo, Fiammetta, additional, Sun, Sainan, additional, Trusel, Luke D., additional, Van Breedam, Jonas, additional, Van Katwyk, Peter, additional, van de Wal, Roderik S. W., additional, Winkelmann, Ricarda, additional, Zhao, Chen, additional, Zhang, Tong, additional, and Zwinger, Thomas, additional

Published
2023
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13. Grounding-line migration in plan-view marine ice-sheet models: results of the ice2sea MISMIP3d intercomparison

Author

Pattyn, Frank, Perichon, Laura, Durand, Gael, Favier, Lionel, Gagliardini, Olivier, Hindmarsh, Richard C.A., Zwinger, Thomas, Albrecht, Torsten, Cornford, Stephen, Docquier, David, Furst, Johannes J, Goldberg, Daniel, Gudmundsson, G. Hilmar, Humbert, Angelika, Hutten, Moritz, Huybrechts, Philippe, Jouvet, Guillaume, Kleiner, Thomas, Larour, Eric, Martin, Daniel, Morlighem, Mathieu, Payne, Anthony J, Pollard, David, Ruckamp, Martin, Rybak, Oleg, Seroussi, Helene, Thoma, Malte, and Wilkens, Nina

Subjects
boundary layer, computer simulation, error analysis, ice sheet, modeling, prediction, spatial variation, steady-state equilibrium
Abstract

Predictions of marine ice-sheet behaviour require models able to simulate grounding-line migration. We present results of an intercomparison experiment for plan-view marine ice-sheet models. Verification is effected by comparison with approximate analytical solutions for flux across the grounding line using simplified geometrical configurations (no lateral variations, no buttressing effects from lateral drag). Perturbation experiments specifying spatial variation in basal sliding parameters permitted the evolution of curved grounding lines, generating buttressing effects. The experiments showed regions of compression and extensional flow across the grounding line, thereby invalidating the boundary layer theory. Steady-state grounding-line positions were found to be dependent on the level of physical model approximation. Resolving grounding lines requires inclusion of membrane stresses, a sufficiently small grid size (

Published
2013

15. Insights on the vulnerability of Antarctic glaciers from the ISMIP6 ice sheet model ensemble and associated uncertainty

Author

Seroussi, Hélène, primary, Verjans, Vincent, additional, Nowicki, Sophie, additional, Payne, Antony J., additional, Goelzer, Heiko, additional, Lipscomb, William H., additional, Abe Ouchi, Ayako, additional, Agosta, Cécile, additional, Albrecht, Torsten, additional, Asay-Davis, Xylar, additional, Barthel, Alice, additional, Calov, Reinhard, additional, Cullather, Richard, additional, Dumas, Christophe, additional, Galton-Fenzi, Benjamin K., additional, Gladstone, Rupert, additional, Golledge, Nicholas R., additional, Gregory, Jonathan M., additional, Greve, Ralf, additional, Hatterman, Tore, additional, Hoffman, Matthew J., additional, Humbert, Angelika, additional, Huybrechts, Philippe, additional, Jourdain, Nicolas C., additional, Kleiner, Thomas, additional, Larour, Eric, additional, Leguy, Gunter R., additional, Lowry, Daniel P., additional, Little, Chistopher M., additional, Morlighem, Mathieu, additional, Pattyn, Frank, additional, Pelle, Tyler, additional, Price, Stephen F., additional, Quiquet, Aurélien, additional, Reese, Ronja, additional, Schlegel, Nicole-Jeanne, additional, Shepherd, Andrew, additional, Simon, Erika, additional, Smith, Robin S., additional, Straneo, Fiametta, additional, Sun, Sainan, additional, Trusel, Luke D., additional, Van Breedam, Jonas, additional, Van Katwyk, Peter, additional, van de Wal, Roderik S. W., additional, Winkelmann, Ricarda, additional, Zhao, Chen, additional, Zhang, Tong, additional, and Zwinger, Thomas, additional

Published
2023
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16. Regularization and L-curves in ice sheet inverse models: a case study in the Filchner–Ronne catchment.

Author

Wolovick, Michael, Humbert, Angelika, Kleiner, Thomas, and Rückamp, Martin

Subjects
ICE sheets, COST functions, HYDROLOGIC models, INVERSE problems, CHARACTERISTIC functions, MATHEMATICAL regularization, INVERSIONS (Geometry)
Abstract

Over the past 3 decades, inversions for ice sheet basal drag have become commonplace in glaciological modeling. Such inversions require regularization to prevent over-fitting and ensure that the structure they recover is a robust inference from the observations, confidence which is required if they are to be used to draw conclusions about processes and properties of the ice base. While L-curve analysis can be used to select the optimal regularization level, the treatment of L-curve analysis in glaciological inverse modeling has been highly variable. Building on the history of glaciological inverse modeling, we demonstrate general best practices for regularizing glaciological inverse problems, using a domain in the Filchner–Ronne catchment of Antarctica as our test bed. We show a step-by-step approach to cost function normalization and L-curve analysis. We explore the spatial and spectral characteristics of the solution as a function of regularization, and we test the sensitivity of L-curve analysis and regularization to model resolution, effective pressure, sliding nonlinearity, and the flow equation. We find that the optimal regularization level converges towards a finite non-zero limit in the continuous problem, associated with a best knowable basal drag field. Nonlinear sliding laws outperform linear sliding in our analysis, with both a lower total variance and a more sharply cornered L-curve. By contrast, geometry-based approximations for effective pressure degrade inversion performance when added to a sliding law, but an actual hydrology model may marginally improve performance in some cases. Our results with 3D inversions suggest that the additional model complexity may not be justified by the 2D nature of the surface velocity data. We conclude with recommendations for best practices in future glaciological inversions. [ABSTRACT FROM AUTHOR]

Published
2023
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17. Temporal activity of subglacial channels around the grounding line of Roi Baudouin Ice Shelf, from ice-penetrating radar

Author

Zhou, Yan, Franke, Steven, Kleiner, Thomas, Drews, Reinhard, Humbert, Angelika, Jansen, Daniela, Eisen, Olaf, Zhou, Yan, Franke, Steven, Kleiner, Thomas, Drews, Reinhard, Humbert, Angelika, Jansen, Daniela, and Eisen, Olaf

Abstract

The existence of ice-shelf basal channels has a significant impact on both buttressing ability and basal melting of ice shelves in Antarctica. Although they can provide a unique perspective of processes for the mass transfer from grounded ice sheet to floating ice shelf, their origination and evolution are still not fully understood. Here we used airborne and ground-based radar to investigate the subglacial channel features at the grounding line (GL). We determined the geometry of five channels (two of which are characterized for the first time) in a set of flow-perpendicular radar profiles, also perpendicular to the channels. We found that the evolution from grounded subglacial channels to the ice-shelf basal channels mainly goes through three stages: (1) The grounded subglacial channels appear 4 to 5 km upstream of the GL and their incision into the ice sheet increases while approaching the GL; (2) as the subglacial channels extend into the grounding zone (1 to 2 km downstream of GL), their inner walls started melting, also they keep their roof-top features; (3) on the shelf interaction with the ocean, surface accumulation and ice dynamics further lead to flattening and widening, progressively turning them into generally known ice-shelf basal channels. Additionally to radar observations, we investigated the role of subglacial hydrology with two modelling approach (subglacial water flux with CUAS-MPI and water routing with CiDRE). A comparison shows that most channel locations in the radar profiles match with areas of higher subglacial water presence, consequently implying that subglacial water flux could mainly be responsible for maintaining the presence of subglacial channels. Based on the already earlier proposed relation that the presence of a sub-ice shelf basal channel is linked to a corresponding channel at the GL, we identify one now active channel at the GL to be related to one which was earlier until 59 years ago. This indicates that basal channels and co

Published
2023

18. A parallel implementation of the confined–unconfined aquifer system model for subglacial hydrology: design, verification, and performance analysis (CUAS-MPI v0.1.0)

Author

Fischler, Yannic, Kleiner, Thomas, Bischof, Christian, Schmiedel, Jeremie, Sayag, Roiy, Emunds, Raban, Oestreich, Lennart Frederik, Humbert, Angelika, Fischler, Yannic, Kleiner, Thomas, Bischof, Christian, Schmiedel, Jeremie, Sayag, Roiy, Emunds, Raban, Oestreich, Lennart Frederik, and Humbert, Angelika

Abstract

Abstract. The subglacial hydrological system affects (i) the motion of ice sheets through sliding, (ii) the location of lakes at the ice margin, and (iii) the ocean circulation by freshwater discharge directly at the grounding line or (iv) via rivers flowing over land. For modeling this hydrology system, a previously developed porous-media concept called the confined–unconfined aquifer system (CUAS) is used. To allow for realistic simulations at the ice sheet scale, we developed CUAS-MPI, an MPI-parallel C/C++ implementation of CUAS (MPI: Message Passing Interface), which employs the Portable, Extensible Toolkit for Scientific Computation (PETSc) infrastructure for handling grids and equation systems. We validate the accuracy of the numerical results by comparing them with a set of analytical solutions to the model equations, which involve two types of boundary conditions. We then investigate the scaling behavior of CUAS-MPI and show that CUAS-MPI scales up to 3840 MPI processes running a realistic Greenland setup on the Lichtenberg HPC system. Our measurements also show that CUAS-MPI reaches a throughput comparable to that of ice sheet simulations, e.g., the Ice-sheet and Sea-level System Model (ISSM). Lastly, we discuss opportunities for ice sheet modeling, explore future coupling possibilities of CUAS-MPI with other simulations, and consider throughput bottlenecks and limits of further scaling.

Published
2023

19. Insights into the vulnerability of Antarctic glaciers from the ISMIP6 ice sheet model ensemble and associated uncertainty

Author

Seroussi, Hélène, Verjans, Vincent, Nowicki, Sophie, Payne, Antony J., Goelzer, Heiko, Lipscomb, William H., Abe-Ouchi, Ayako, Agosta, Cécile, Albrecht, Torsten, Asay-Davis, Xylar, Barthel, Alice, Calov, Reinhard, Cullather, Richard, Dumas, Christophe, Galton-Fenzi, Benjamin K., Gladstone, Rupert, Golledge, Nicholas R., Gregory, Jonathan M., Greve, Ralf, Hattermann, Tore, Hoffman, Matthew J., Humbert, Angelika, Huybrechts, Philippe, Jourdain, Nicolas C., Kleiner, Thomas, Larour, Eric, Leguy, Gunter R., Lowry, Daniel P., Little, Chistopher M., Morlighem, Mathieu, Pattyn, Frank, Pelle, Tyler, Price, Stephen F., Quiquet, Aurélien, Reese, Ronja, Schlegel, Nicole Jeanne, Shepherd, Andrew, Simon, Erika, Smith, Robin S., Straneo, Fiammetta, Sun, Sainan, Trusel, Luke D., Van Breedam, Jonas, Van Katwyk, Peter, van de Wal, Roderik S.W., Winkelmann, Ricarda, Zhao, Chen, Zhang, Tong, Zwinger, Thomas, Seroussi, Hélène, Verjans, Vincent, Nowicki, Sophie, Payne, Antony J., Goelzer, Heiko, Lipscomb, William H., Abe-Ouchi, Ayako, Agosta, Cécile, Albrecht, Torsten, Asay-Davis, Xylar, Barthel, Alice, Calov, Reinhard, Cullather, Richard, Dumas, Christophe, Galton-Fenzi, Benjamin K., Gladstone, Rupert, Golledge, Nicholas R., Gregory, Jonathan M., Greve, Ralf, Hattermann, Tore, Hoffman, Matthew J., Humbert, Angelika, Huybrechts, Philippe, Jourdain, Nicolas C., Kleiner, Thomas, Larour, Eric, Leguy, Gunter R., Lowry, Daniel P., Little, Chistopher M., Morlighem, Mathieu, Pattyn, Frank, Pelle, Tyler, Price, Stephen F., Quiquet, Aurélien, Reese, Ronja, Schlegel, Nicole Jeanne, Shepherd, Andrew, Simon, Erika, Smith, Robin S., Straneo, Fiammetta, Sun, Sainan, Trusel, Luke D., Van Breedam, Jonas, Van Katwyk, Peter, van de Wal, Roderik S.W., Winkelmann, Ricarda, Zhao, Chen, Zhang, Tong, and Zwinger, Thomas

Abstract

The Antarctic Ice Sheet represents the largest source of uncertainty in future sea level rise projections, with a contribution to sea level by 2100 ranging from −5 to 43 cm of sea level equivalent under high carbon emission scenarios estimated by the recent Ice Sheet Model Intercomparison for CMIP6 (ISMIP6). ISMIP6 highlighted the different behaviors of the East and West Antarctic ice sheets, as well as the possible role of increased surface mass balance in offsetting the dynamic ice loss in response to changing oceanic conditions in ice shelf cavities. However, the detailed contribution of individual glaciers, as well as the partitioning of uncertainty associated with this ensemble, have not yet been investigated. Here, we analyze the ISMIP6 results for high carbon emission scenarios, focusing on key glaciers around the Antarctic Ice Sheet, and we quantify their projected dynamic mass loss, defined here as mass loss through increased ice discharge into the ocean in response to changing oceanic conditions. We highlight glaciers contributing the most to sea level rise, as well as their vulnerability to changes in oceanic conditions. We then investigate the different sources of uncertainty and their relative role in projections, for the entire continent and for key individual glaciers. We show that, in addition to Thwaites and Pine Island glaciers in West Antarctica, Totten and Moscow University glaciers in East Antarctica present comparable future dynamic mass loss and high sensitivity to ice shelf basal melt. The overall uncertainty in additional dynamic mass loss in response to changing oceanic conditions, compared to a scenario with constant oceanic conditions, is dominated by the choice of ice sheet model, accounting for 52 % of the total uncertainty of the Antarctic dynamic mass loss in 2100. Its relative role for the most dynamic glaciers varies between 14 % for MacAyeal and Whillans ice streams and 56 % for Pine Island Glacier at the end of the century. The

Published
2023

20. Insights into the vulnerability of Antarctic glaciers from the ISMIP6 ice sheet model ensemble and associated uncertainty

Author

Sub Dynamics Meteorology, Proceskunde, Sub Algemeen Marine & Atmospheric Res, Marine and Atmospheric Research, Seroussi, Hélène, Verjans, Vincent, Nowicki, Sophie, Payne, Antony J., Goelzer, Heiko, Lipscomb, William H., Abe-Ouchi, Ayako, Agosta, Cécile, Albrecht, Torsten, Asay-Davis, Xylar, Barthel, Alice, Calov, Reinhard, Cullather, Richard, Dumas, Christophe, Galton-Fenzi, Benjamin K., Gladstone, Rupert, Golledge, Nicholas R., Gregory, Jonathan M., Greve, Ralf, Hattermann, Tore, Hoffman, Matthew J., Humbert, Angelika, Huybrechts, Philippe, Jourdain, Nicolas C., Kleiner, Thomas, Larour, Eric, Leguy, Gunter R., Lowry, Daniel P., Little, Chistopher M., Morlighem, Mathieu, Pattyn, Frank, Pelle, Tyler, Price, Stephen F., Quiquet, Aurélien, Reese, Ronja, Schlegel, Nicole Jeanne, Shepherd, Andrew, Simon, Erika, Smith, Robin S., Straneo, Fiammetta, Sun, Sainan, Trusel, Luke D., Van Breedam, Jonas, Van Katwyk, Peter, van de Wal, Roderik S.W., Winkelmann, Ricarda, Zhao, Chen, Zhang, Tong, Zwinger, Thomas, Sub Dynamics Meteorology, Proceskunde, Sub Algemeen Marine & Atmospheric Res, Marine and Atmospheric Research, Seroussi, Hélène, Verjans, Vincent, Nowicki, Sophie, Payne, Antony J., Goelzer, Heiko, Lipscomb, William H., Abe-Ouchi, Ayako, Agosta, Cécile, Albrecht, Torsten, Asay-Davis, Xylar, Barthel, Alice, Calov, Reinhard, Cullather, Richard, Dumas, Christophe, Galton-Fenzi, Benjamin K., Gladstone, Rupert, Golledge, Nicholas R., Gregory, Jonathan M., Greve, Ralf, Hattermann, Tore, Hoffman, Matthew J., Humbert, Angelika, Huybrechts, Philippe, Jourdain, Nicolas C., Kleiner, Thomas, Larour, Eric, Leguy, Gunter R., Lowry, Daniel P., Little, Chistopher M., Morlighem, Mathieu, Pattyn, Frank, Pelle, Tyler, Price, Stephen F., Quiquet, Aurélien, Reese, Ronja, Schlegel, Nicole Jeanne, Shepherd, Andrew, Simon, Erika, Smith, Robin S., Straneo, Fiammetta, Sun, Sainan, Trusel, Luke D., Van Breedam, Jonas, Van Katwyk, Peter, van de Wal, Roderik S.W., Winkelmann, Ricarda, Zhao, Chen, Zhang, Tong, and Zwinger, Thomas

Published
2023

24. initMIP-Antarctica: an Ice Sheet Model Initialization Experiment of ISMIP6

Author

Seroussi, Helene, Nowicki, Sophie, Simon, Erika, Abe-Ouchi, Ayako, Albrecht, Torsten, Brondex, Julien, Cornford, Stephen, Dumas, Christophe, Gillet-Chaulet, Fabien, Goelzer, Heiko, Golledge, Nicholas R, Gregory, Jonathan M, Greve, Ralf, Hoffman, Matthew J, Humbert, Angelika, Huybrechts, Philippe, Kleiner, Thomas, Larour, Eric, Leguy, Gunter, Lipscomb, William H, Lowry, Daniel, Mengel, Matthias, Morlighem, Mathieu, Pattyn, Frank, Payne, Anthony J, Pollard, David, Price, Stephen F, Quiquet, Aurélien, Reerink, Thomas J, Reese, Ronja, Rodehacke, Christian B, Schlegel, Nicole-Jeanne, Shepherd, Andrew, Sun, Sainan, Sutter, Johannes, Breedam, Jonas Van, Wal, Roderik S. W. van de, Winkelmann, Ricarda, and Zhang, Tong

Subjects
Geosciences (General)
Abstract

Ice sheet numerical modeling is an important tool to estimate the dynamic contribution of the Antarctic ice sheet to sea level rise over the coming centuries. The influence of initial conditions on ice sheet model simulations, however, is still unclear. To better understand this influence, an initial state intercomparison exercise (initMIP) has been developed to compare, evaluate, and improve initialization procedures and estimate their impact on century-scale simulations. initMIP is the first set of experiments of the Ice Sheet Model Intercomparison Project for CMIP6 (ISMIP6), which is the primary Coupled Model Intercomparison Project Phase 6 (CMIP6) activity focusing on the Greenland and Antarctic ice sheets. Following initMIP-Greenland, initMIP-Antarctica has been designed to explore uncertainties associated with model initialization and spin-up and to evaluate the impact of changes in external forcings. Starting from the state of the Antarctic ice sheet at the end of the initialization procedure, three forward experiments are each run for 100 years: a control run, a run with a surface mass balance anomaly, and a run with a basal melting anomaly beneath floating ice. This study presents the results of initMIP-Antarctica from 25 simulations performed by 16 international modeling groups. The submitted results use different initial conditions and initialization methods, as well as ice flow model parameters and reference external forcings. We find a good agreement among model responses to the surface mass balance anomaly but large variations in responses to the basal melting anomaly. These variations can be attributed to differences in the extent of ice shelves and their upstream tributaries, the numerical treatment of grounding line, and the initial ocean conditions applied, suggesting that ongoing efforts to better represent ice shelves in continental-scale models should continue.

Published
2019
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26. Über numerische Strömungsmechanik und die Kondensation von Reinstoffen an horizontalen Rohren

Author

Kleiner, Thomas, Klein, Harald (Prof. Dr.), and Hinrichsen, Kai-Olaf Martin (Prof. Dr.)

Subjects
Ingenieurwissenschaften, ddc:660, Condensation, Phase change, Tube bundle condensers, CFD, Volume-of-Fluid method, OpenFOAM, Chemische Verfahrenstechnik, ddc:620, Kondensation, Phasenwechsel, Rohrbündelkondensator, CFD, Volume-of-Fluid Methode, OpenFOAM
Abstract

Pure substance condensation on horizontal low finned tubes was investigated with computational fluid dynamics. Highly resolved simulations were carried out using a rigorous simulation approach and the Volume-of-Fluid method. The simulations show excellent agreement with measurements found in literature and enable detailed investigations of condensation on horizontal tubes. Die Kondensation von Reinstoffen an niedrig berippten horizontalen Rohren wurde mittels numerischer Strömungsmechanik untersucht. Hierbei wurden hochaufgelöste Simulationen mit einem rigorosen Simulationsansatz unter Verwendung der Volume-of-Fluid-Methode durchgeführt. Die Simulationen zeigen sehr gute Übereinstimmungen mit Messergebnissen aus der Literatur und ermöglichen eine detaillierte Untersuchungen des Kondensationsvorgangs an horizontalen Rohren.

Published
2022

27. Impact of paleoclimate on present and future evolution of the Greenland Ice Sheet

Author

Yang, Hu, Krebs-Kanzow, Uta, Kleiner, Thomas, Sidorenko, Dmitry, Rodehacke, Christian, Shi, Xiaoxu, Gierz, Paul, Niu, Lu, Gowan, Evan, Hinck, Sebastian, Liu, Xingxing, Stap, Lennert, Lohmann, Gerrit, Yang, Hu, Krebs-Kanzow, Uta, Kleiner, Thomas, Sidorenko, Dmitry, Rodehacke, Christian, Shi, Xiaoxu, Gierz, Paul, Niu, Lu, Gowan, Evan, Hinck, Sebastian, Liu, Xingxing, Stap, Lennert, and Lohmann, Gerrit

Abstract

Using transient climate forcing based on simulations from the Alfred Wegener Institute Earth System Model (AWI-ESM), we simulate the evolution of the Greenland Ice Sheet (GrIS) from the last interglacial (125 ka, kiloyear before present) to 2100 AD with the Parallel Ice Sheet Model (PISM). The impact of paleoclimate, especially Holocene climate, on the present and future evolution of the GrIS is explored. Our simulations of the past show close agreement with reconstructions with respect to the recent timing of the peaks in ice volume and the climate of Greenland. The maximum and minimum ice volume at around 18–17 ka and 6–5 ka lag the respective extremes in climate by several thousand years, implying that the ice volume response of the GrIS strongly lags climatic changes. Given that Greenland’s climate was getting colder from the Holocene Thermal Maximum (i.e., 8 ka) to the Pre-Industrial era, our simulation implies that the GrIS experienced growth from the mid-Holocene to the industrial era. Due to this background trend, the GrIS still gains mass until the second half of the 20th century, even though anthropogenic warming begins around 1850 AD. This is also in agreement with observational evidence showing mass loss of the GrIS does not begin earlier than the late 20th century. Our results highlight that the present evolution of the GrIS is not only controlled by the recent climate changes, but is also affected by paleoclimate, especially the relatively warm Holocene climate. We propose that the GrIS was not in equilibrium throughout the entire Holocene and that the slow response to Holocene climate needs to be represented in ice sheet simulations in order to predict ice mass loss, and therefore sea level rise, accurately.

Published
2022

28. Impact of paleoclimate on present and future evolution of the Greenland Ice Sheet

Author

Sub Dynamics Meteorology, Marine and Atmospheric Research, Yang, Hu, Krebs-Kanzow, Uta, Kleiner, Thomas, Sidorenko, Dmitry, Rodehacke, Christian, Shi, Xiaoxu, Gierz, Paul, Niu, Lu, Gowan, Evan, Hinck, Sebastian, Liu, Xingxing, Stap, Lennert, Lohmann, Gerrit, Sub Dynamics Meteorology, Marine and Atmospheric Research, Yang, Hu, Krebs-Kanzow, Uta, Kleiner, Thomas, Sidorenko, Dmitry, Rodehacke, Christian, Shi, Xiaoxu, Gierz, Paul, Niu, Lu, Gowan, Evan, Hinck, Sebastian, Liu, Xingxing, Stap, Lennert, and Lohmann, Gerrit

Published
2022

29. Comparison of ice dynamics using full-Stokes and Blatter–Pattyn approximation: application to the Northeast Greenland Ice Stream

Author

Rückamp, Martin, Kleiner, Thomas, Humbert, Angelika, Rückamp, Martin, Kleiner, Thomas, and Humbert, Angelika

Abstract

Full-Stokes (FS) ice sheet models provide the most sophisticated formulation of ice sheet flow. However, their applicability is often limited due to the high computational demand and numerical challenges. To balance computational demand and accuracy, the so-called Blatter–Pattyn (BP) stress regime is frequently used. Here, we explore the dynamic consequences of using simplified approaches by solving FS and the BP stress regime applied to the Northeast Greenland Ice Stream. To ensure a consistent comparison, we use one single ice sheet model to run the simulations under identical numerical conditions. A sensitivity study to the horizontal grid resolution (from 12.8 to a resolution of 0.1 km) reveals that velocity differences between the FS and BP solution emerge below ∼ 1 km horizontal resolution and continuously increase with resolution. Over the majority of the modelling domain both models reveal similar surface velocity patterns. At the grounding line of the 79∘ North Glacier the simulations show considerable differences whereby the BP model overestimates ice discharge of up to 50 % compared to FS. A sensitivity study to the friction type reveals that differences are stronger for a power-law friction than a linear friction law. Model differences are attributed to topographic variability and the basal drag, in which neglected stress terms in BP become important.

Published
2022

30. About Computational Fluid Dynamics and the Simulation of Pure Substance Condensation on Horizontal Tubes

Author

Klein, Harald (Prof. Dr.), Klein, Harald (Prof. Dr.);Hinrichsen, Kai-Olaf Martin (Prof. Dr.), Kleiner, Thomas, Klein, Harald (Prof. Dr.), Klein, Harald (Prof. Dr.);Hinrichsen, Kai-Olaf Martin (Prof. Dr.), and Kleiner, Thomas

Abstract

Pure substance condensation on horizontal low finned tubes was investigated with computational fluid dynamics. Highly resolved simulations were carried out using a rigorous simulation approach and the Volume-of-Fluid method. The simulations show excellent agreement with measurements found in literature and enable detailed investigations of condensation on horizontal tubes., Die Kondensation von Reinstoffen an niedrig berippten horizontalen Rohren wurde mittels numerischer Strömungsmechanik untersucht. Hierbei wurden hochaufgelöste Simulationen mit einem rigorosen Simulationsansatz unter Verwendung der Volume-of-Fluid-Methode durchgeführt. Die Simulationen zeigen sehr gute Übereinstimmungen mit Messergebnissen aus der Literatur und ermöglichen eine detaillierte Untersuchungen des Kondensationsvorgangs an horizontalen Rohren.

Published
2022

35. Impact of paleoclimate on present and future evolution of the Greenland Ice Sheet

Author

Yang, Hu, primary, Krebs-Kanzow, Uta, additional, Kleiner, Thomas, additional, Sidorenko, Dmitry, additional, Rodehacke, Christian Bernd, additional, Shi, Xiaoxu, additional, Gierz, Paul, additional, Niu, Lu, additional, Gowan, Evan J., additional, Hinck, Sebastian, additional, Liu, Xingxing, additional, Stap, Lennert B., additional, and Lohmann, Gerrit, additional

Published
2022
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37. Future Sea Level Change Under Coupled Model Intercomparison Project Phase 5 and Phase 6 Scenarios From the Greenland and Antarctic Ice Sheets

Author

Payne, Antony J., primary, Nowicki, Sophie, additional, Abe‐Ouchi, Ayako, additional, Agosta, Cécile, additional, Alexander, Patrick, additional, Albrecht, Torsten, additional, Asay‐Davis, Xylar, additional, Aschwanden, Andy, additional, Barthel, Alice, additional, Bracegirdle, Thomas J., additional, Calov, Reinhard, additional, Chambers, Christopher, additional, Choi, Youngmin, additional, Cullather, Richard, additional, Cuzzone, Joshua, additional, Dumas, Christophe, additional, Edwards, Tamsin L., additional, Felikson, Denis, additional, Fettweis, Xavier, additional, Galton‐Fenzi, Benjamin K., additional, Goelzer, Heiko, additional, Gladstone, Rupert, additional, Golledge, Nicholas R., additional, Gregory, Jonathan M., additional, Greve, Ralf, additional, Hattermann, Tore, additional, Hoffman, Matthew J., additional, Humbert, Angelika, additional, Huybrechts, Philippe, additional, Jourdain, Nicolas C., additional, Kleiner, Thomas, additional, Munneke, Peter Kuipers, additional, Larour, Eric, additional, Le clec'h, Sebastien, additional, Lee, Victoria, additional, Leguy, Gunter, additional, Lipscomb, William H., additional, Little, Christopher M., additional, Lowry, Daniel P., additional, Morlighem, Mathieu, additional, Nias, Isabel, additional, Pattyn, Frank, additional, Pelle, Tyler, additional, Price, Stephen F., additional, Quiquet, Aurélien, additional, Reese, Ronja, additional, Rückamp, Martin, additional, Schlegel, Nicole‐Jeanne, additional, Seroussi, Hélène, additional, Shepherd, Andrew, additional, Simon, Erika, additional, Slater, Donald, additional, Smith, Robin S., additional, Straneo, Fiammetta, additional, Sun, Sainan, additional, Tarasov, Lev, additional, Trusel, Luke D., additional, Van Breedam, Jonas, additional, van de Wal, Roderik, additional, van den Broeke, Michiel, additional, Winkelmann, Ricarda, additional, Zhao, Chen, additional, Zhang, Tong, additional, and Zwinger, Thomas, additional

Published
2021
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39. Future Sea Level Change Under Coupled Model Intercomparison Project Phase 5 and Phase 6 Scenarios From the Greenland and Antarctic Ice Sheets

Author

Payne, Antony J., Nowicki, Sophie, Abe-Ouchi, Ayako, Agosta, Cécile, Alexander, Patrick, Albrecht, Torsten, Asay-Davis, Xylar, Aschwanden, Andy, Barthel, Alice, Bracegirdle, Thomas J., Calov, Reinhard, Chambers, Christopher, Choi, Youngmin, Cullather, Richard, Cuzzone, Joshua, Dumas, Christophe, Edwards, Tamsin L., Felikson, Denis, Fettweis, Xavier, Galton-Fenzi, Benjamin K., Goelzer, Heiko, Gladstone, Rupert, Golledge, Nicholas R., Gregory, Jonathan M., Greve, Ralf, Hattermann, Tore, Hoffman, Matthew J., Humbert, Angelika, Huybrechts, Philippe, Jourdain, Nicolas C., Kleiner, Thomas, Munneke, Peter Kuipers, Larour, Eric, Le clec'h, Sebastien, Lee, Victoria, Leguy, Gunter, Lipscomb, William H., Little, Christopher M., Lowry, Daniel P., Morlighem, Mathieu, Nias, Isabel, Pattyn, Frank, Pelle, Tyler, Price, Stephen F., Quiquet, Aurélien, Reese, Ronja, Rückamp, Martin, Schlegel, Nicole Jeanne, Seroussi, Hélène, Shepherd, Andrew, Simon, Erika, Slater, Donald, Smith, Robin S., Straneo, Fiammetta, Sun, Sainan, Tarasov, Lev, Trusel, Luke D., Van Breedam, Jonas, van de Wal, Roderik, van den Broeke, Michiel, Winkelmann, Ricarda, Zhao, Chen, Zhang, Tong, Zwinger, Thomas, Payne, Antony J., Nowicki, Sophie, Abe-Ouchi, Ayako, Agosta, Cécile, Alexander, Patrick, Albrecht, Torsten, Asay-Davis, Xylar, Aschwanden, Andy, Barthel, Alice, Bracegirdle, Thomas J., Calov, Reinhard, Chambers, Christopher, Choi, Youngmin, Cullather, Richard, Cuzzone, Joshua, Dumas, Christophe, Edwards, Tamsin L., Felikson, Denis, Fettweis, Xavier, Galton-Fenzi, Benjamin K., Goelzer, Heiko, Gladstone, Rupert, Golledge, Nicholas R., Gregory, Jonathan M., Greve, Ralf, Hattermann, Tore, Hoffman, Matthew J., Humbert, Angelika, Huybrechts, Philippe, Jourdain, Nicolas C., Kleiner, Thomas, Munneke, Peter Kuipers, Larour, Eric, Le clec'h, Sebastien, Lee, Victoria, Leguy, Gunter, Lipscomb, William H., Little, Christopher M., Lowry, Daniel P., Morlighem, Mathieu, Nias, Isabel, Pattyn, Frank, Pelle, Tyler, Price, Stephen F., Quiquet, Aurélien, Reese, Ronja, Rückamp, Martin, Schlegel, Nicole Jeanne, Seroussi, Hélène, Shepherd, Andrew, Simon, Erika, Slater, Donald, Smith, Robin S., Straneo, Fiammetta, Sun, Sainan, Tarasov, Lev, Trusel, Luke D., Van Breedam, Jonas, van de Wal, Roderik, van den Broeke, Michiel, Winkelmann, Ricarda, Zhao, Chen, Zhang, Tong, and Zwinger, Thomas

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.

Published
2021

40. Projected land ice contributions to twenty-first-century sea level rise

Author

Edwards, Tamsin L., Nowicki, Sophie, Marzeion, Ben, Hock, Regine, Goelzer, Heiko, Seroussi, Hélène, Jourdain, Nicolas C., Slater, Donald A., Turner, Fiona E., Smith, Christopher J., McKenna, Christine M., Simon, Erika, Abe-Ouchi, Ayako, Gregory, Jonathan M., Larour, Eric, Lipscomb, William H., Payne, Antony J., Shepherd, Andrew, Agosta, Cécile, Alexander, Patrick, Albrecht, Torsten, Anderson, Brian, Asay-Davis, Xylar, Aschwanden, Andy, Barthel, Alice, Bliss, Andrew, Calov, Reinhard, Chambers, Christopher, Champollion, Nicolas, Choi, Youngmin, Cullather, Richard, Cuzzone, Joshua, Dumas, Christophe, Felikson, Denis, Fettweis, Xavier, Fujita, Koji, Galton-Fenzi, Benjamin K., Gladstone, Rupert, Golledge, Nicholas R., Greve, Ralf, Hattermann, Tore, Hoffman, Matthew J., Humbert, Angelika, Huss, Matthias, Huybrechts, Philippe, Immerzeel, Walter, Kleiner, Thomas, Kraaijenbrink, Philip, Le clec’h, Sébastien, Lee, Victoria, Leguy, Gunter R., Little, Christopher M., Lowry, Daniel P., Malles, Jan-Hendrik, Martin, Daniel F., Maussion, Fabien, Morlighem, Mathieu, O’Neill, James F., Nias, Isabel, Pattyn, Frank, Pelle, Tyler, Price, Stephen F., Quiquet, Aurélien, Radić, Valentina, Reese, Ronja, Rounce, David R., Rückamp, Martin, Sakai, Akiko, Shafer, Courtney, Schlegel, Nicole-Jeanne, Shannon, Sarah, Smith, Robin S., Straneo, Fiammetta, Sun, Sainan, Tarasov, Lev, Trusel, Luke D., Van Breedam, Jonas, van de Wal, Roderik, van den Broeke, Michiel, Winkelmann, Ricarda, Zekollari, Harry, Zhao, Chen, Zhang, Tong, Zwinger, Thomas, Edwards, Tamsin L., Nowicki, Sophie, Marzeion, Ben, Hock, Regine, Goelzer, Heiko, Seroussi, Hélène, Jourdain, Nicolas C., Slater, Donald A., Turner, Fiona E., Smith, Christopher J., McKenna, Christine M., Simon, Erika, Abe-Ouchi, Ayako, Gregory, Jonathan M., Larour, Eric, Lipscomb, William H., Payne, Antony J., Shepherd, Andrew, Agosta, Cécile, Alexander, Patrick, Albrecht, Torsten, Anderson, Brian, Asay-Davis, Xylar, Aschwanden, Andy, Barthel, Alice, Bliss, Andrew, Calov, Reinhard, Chambers, Christopher, Champollion, Nicolas, Choi, Youngmin, Cullather, Richard, Cuzzone, Joshua, Dumas, Christophe, Felikson, Denis, Fettweis, Xavier, Fujita, Koji, Galton-Fenzi, Benjamin K., Gladstone, Rupert, Golledge, Nicholas R., Greve, Ralf, Hattermann, Tore, Hoffman, Matthew J., Humbert, Angelika, Huss, Matthias, Huybrechts, Philippe, Immerzeel, Walter, Kleiner, Thomas, Kraaijenbrink, Philip, Le clec’h, Sébastien, Lee, Victoria, Leguy, Gunter R., Little, Christopher M., Lowry, Daniel P., Malles, Jan-Hendrik, Martin, Daniel F., Maussion, Fabien, Morlighem, Mathieu, O’Neill, James F., Nias, Isabel, Pattyn, Frank, Pelle, Tyler, Price, Stephen F., Quiquet, Aurélien, Radić, Valentina, Reese, Ronja, Rounce, David R., Rückamp, Martin, Sakai, Akiko, Shafer, Courtney, Schlegel, Nicole-Jeanne, Shannon, Sarah, Smith, Robin S., Straneo, Fiammetta, Sun, Sainan, Tarasov, Lev, Trusel, Luke D., Van Breedam, Jonas, van de Wal, Roderik, van den Broeke, Michiel, Winkelmann, Ricarda, Zekollari, Harry, Zhao, Chen, Zhang, Tong, and Zwinger, Thomas

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.

Published
2021
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41. Future Sea Level Change Under Coupled Model Intercomparison Project Phase 5 and Phase 6 Scenarios From the Greenland and Antarctic Ice Sheets

Author

Marine and Atmospheric Research, Sub Dynamics Meteorology, Proceskunde, Sub Algemeen Marine & Atmospheric Res, Payne, Antony J., Nowicki, Sophie, Abe-Ouchi, Ayako, Agosta, Cécile, Alexander, Patrick, Albrecht, Torsten, Asay-Davis, Xylar, Aschwanden, Andy, Barthel, Alice, Bracegirdle, Thomas J., Calov, Reinhard, Chambers, Christopher, Choi, Youngmin, Cullather, Richard, Cuzzone, Joshua, Dumas, Christophe, Edwards, Tamsin L., Felikson, Denis, Fettweis, Xavier, Galton-Fenzi, Benjamin K., Goelzer, Heiko, Gladstone, Rupert, Golledge, Nicholas R., Gregory, Jonathan M., Greve, Ralf, Hattermann, Tore, Hoffman, Matthew J., Humbert, Angelika, Huybrechts, Philippe, Jourdain, Nicolas C., Kleiner, Thomas, Munneke, Peter Kuipers, Larour, Eric, Le clec'h, Sebastien, Lee, Victoria, Leguy, Gunter, Lipscomb, William H., Little, Christopher M., Lowry, Daniel P., Morlighem, Mathieu, Nias, Isabel, Pattyn, Frank, Pelle, Tyler, Price, Stephen F., Quiquet, Aurélien, Reese, Ronja, Rückamp, Martin, Schlegel, Nicole Jeanne, Seroussi, Hélène, Shepherd, Andrew, Simon, Erika, Slater, Donald, Smith, Robin S., Straneo, Fiammetta, Sun, Sainan, Tarasov, Lev, Trusel, Luke D., Van Breedam, Jonas, van de Wal, Roderik, van den Broeke, Michiel, Winkelmann, Ricarda, Zhao, Chen, Zhang, Tong, Zwinger, Thomas, Marine and Atmospheric Research, Sub Dynamics Meteorology, Proceskunde, Sub Algemeen Marine & Atmospheric Res, Payne, Antony J., Nowicki, Sophie, Abe-Ouchi, Ayako, Agosta, Cécile, Alexander, Patrick, Albrecht, Torsten, Asay-Davis, Xylar, Aschwanden, Andy, Barthel, Alice, Bracegirdle, Thomas J., Calov, Reinhard, Chambers, Christopher, Choi, Youngmin, Cullather, Richard, Cuzzone, Joshua, Dumas, Christophe, Edwards, Tamsin L., Felikson, Denis, Fettweis, Xavier, Galton-Fenzi, Benjamin K., Goelzer, Heiko, Gladstone, Rupert, Golledge, Nicholas R., Gregory, Jonathan M., Greve, Ralf, Hattermann, Tore, Hoffman, Matthew J., Humbert, Angelika, Huybrechts, Philippe, Jourdain, Nicolas C., Kleiner, Thomas, Munneke, Peter Kuipers, Larour, Eric, Le clec'h, Sebastien, Lee, Victoria, Leguy, Gunter, Lipscomb, William H., Little, Christopher M., Lowry, Daniel P., Morlighem, Mathieu, Nias, Isabel, Pattyn, Frank, Pelle, Tyler, Price, Stephen F., Quiquet, Aurélien, Reese, Ronja, Rückamp, Martin, Schlegel, Nicole Jeanne, Seroussi, Hélène, Shepherd, Andrew, Simon, Erika, Slater, Donald, Smith, Robin S., Straneo, Fiammetta, Sun, Sainan, Tarasov, Lev, Trusel, Luke D., Van Breedam, Jonas, van de Wal, Roderik, van den Broeke, Michiel, Winkelmann, Ricarda, Zhao, Chen, Zhang, Tong, and Zwinger, Thomas

Published
2021

42. Projected land ice contributions to twenty-first-century sea level rise

Author

Sub Dynamics Meteorology, Hydrologie, Landscape functioning, Geocomputation and Hydrology, Proceskunde, Sub Algemeen Marine & Atmospheric Res, Edwards, Tamsin L, Nowicki, Sophie, Marzeion, Ben, Hock, Regine, Goelzer, Heiko, Seroussi, Hélène, Jourdain, Nicolas C, Slater, Donald A, Turner, Fiona E, Smith, Christopher J, McKenna, Christine M, Simon, Erika, Abe-Ouchi, Ayako, Gregory, Jonathan M, Larour, Eric, Lipscomb, William H, Payne, Antony J, Shepherd, Andrew, Agosta, Cécile, Alexander, Patrick, Albrecht, Torsten, Anderson, Brian, Asay-Davis, Xylar, Aschwanden, Andy, Barthel, Alice, Bliss, Andrew, Calov, Reinhard, Chambers, Christopher, Champollion, Nicolas, Choi, Youngmin, Cullather, Richard, Cuzzone, Joshua, Dumas, Christophe, Felikson, Denis, Fettweis, Xavier, Fujita, Koji, Galton-Fenzi, Benjamin K, Gladstone, Rupert, Golledge, Nicholas R, Greve, Ralf, Hattermann, Tore, Hoffman, Matthew J, Humbert, Angelika, Huss, Matthias, Huybrechts, Philippe, Immerzeel, Walter, Kleiner, Thomas, Kraaijenbrink, Philip, Le Clec'h, Sébastien, Lee, Victoria, Leguy, Gunter R, Little, Christopher M, Lowry, Daniel P, Malles, Jan-Hendrik, Martin, Daniel F, Maussion, Fabien, Morlighem, Mathieu, O'Neill, James F, Nias, Isabel, Pattyn, Frank, Pelle, Tyler, Price, Stephen F, Quiquet, Aurélien, Radić, Valentina, Reese, Ronja, Rounce, David R, Rückamp, Martin, Sakai, Akiko, Shafer, Courtney, Schlegel, Nicole-Jeanne, Shannon, Sarah, Smith, Robin S, Straneo, Fiammetta, Sun, Sainan, Tarasov, Lev, Trusel, Luke D, Van Breedam, Jonas, van de Wal, Roderik, van den Broeke, Michiel, Winkelmann, Ricarda, Zekollari, Harry, Zhao, Chen, Zhang, Tong, Zwinger, Thomas, Sub Dynamics Meteorology, Hydrologie, Landscape functioning, Geocomputation and Hydrology, Proceskunde, Sub Algemeen Marine & Atmospheric Res, Edwards, Tamsin L, Nowicki, Sophie, Marzeion, Ben, Hock, Regine, Goelzer, Heiko, Seroussi, Hélène, Jourdain, Nicolas C, Slater, Donald A, Turner, Fiona E, Smith, Christopher J, McKenna, Christine M, Simon, Erika, Abe-Ouchi, Ayako, Gregory, Jonathan M, Larour, Eric, Lipscomb, William H, Payne, Antony J, Shepherd, Andrew, Agosta, Cécile, Alexander, Patrick, Albrecht, Torsten, Anderson, Brian, Asay-Davis, Xylar, Aschwanden, Andy, Barthel, Alice, Bliss, Andrew, Calov, Reinhard, Chambers, Christopher, Champollion, Nicolas, Choi, Youngmin, Cullather, Richard, Cuzzone, Joshua, Dumas, Christophe, Felikson, Denis, Fettweis, Xavier, Fujita, Koji, Galton-Fenzi, Benjamin K, Gladstone, Rupert, Golledge, Nicholas R, Greve, Ralf, Hattermann, Tore, Hoffman, Matthew J, Humbert, Angelika, Huss, Matthias, Huybrechts, Philippe, Immerzeel, Walter, Kleiner, Thomas, Kraaijenbrink, Philip, Le Clec'h, Sébastien, Lee, Victoria, Leguy, Gunter R, Little, Christopher M, Lowry, Daniel P, Malles, Jan-Hendrik, Martin, Daniel F, Maussion, Fabien, Morlighem, Mathieu, O'Neill, James F, Nias, Isabel, Pattyn, Frank, Pelle, Tyler, Price, Stephen F, Quiquet, Aurélien, Radić, Valentina, Reese, Ronja, Rounce, David R, Rückamp, Martin, Sakai, Akiko, Shafer, Courtney, Schlegel, Nicole-Jeanne, Shannon, Sarah, Smith, Robin S, Straneo, Fiammetta, Sun, Sainan, Tarasov, Lev, Trusel, Luke D, Van Breedam, Jonas, van de Wal, Roderik, van den Broeke, Michiel, Winkelmann, Ricarda, Zekollari, Harry, Zhao, Chen, Zhang, Tong, and Zwinger, Thomas

Published
2021

43. Future sea level change under Coupled Model Intercomparison Project phase 5 and 6 scenarios from the Greenland and Antarctic ice sheets

Author

Payne, Antony J., Nowicki, Sophie, Abe‐Ouchi, Ayako, Agosta, Cécile, Alexander, Patrick, Albrecht, Torsten, Asay‐Davis, Xylar, Aschwanden, Andy, Barthel, Alice, Bracegirdle, Thomas J., Calov, Reinhard, Chambers, Christopher, Choi, Youngmin, Cullather, Richard, Cuzzone, Joshua, Dumas, Christophe, Edwards, Tamsin L., Felikson, Denis, Fettweis, Xavier, Galton‐Fenzi, Benjamin K., Goelzer, Heiko, Gladstone, Rupert, Golledge, Nicholas R., Gregory, Jonathan M., Greve, Ralf, Hattermann, Tore, Hoffman, Matthew J., Humbert, Angelika, Huybrechts, Philippe, Jourdain, Nicolas C., Kleiner, Thomas, Munneke, Peter Kuipers, Larour, Eric, Le clec'h, Sebastien, Lee, Victoria, Leguy, Gunter, Lipscomb, William H., Little, Christopher M., Lowry, Daniel P., Morlighem, Mathieu, Nias, Isabel, Pattyn, Frank, Pelle, Tyler, Price, Stephen F., Quiquet, Aurélien, Reese, Ronja, Rückamp, Martin, Schlegel, Nicole‐Jeanne, Seroussi, Hélène, Shepherd, Andrew, Simon, Erika, Slater, Donald, Smith, Robin S., Straneo, Fiammetta, Sun, Sainan, Tarasov, Lev, Trusel, Luke D., Van Breedam, Jonas, van de Wal, Roderik, van den Broeke, Michiel, Winkelmann, Ricarda, Zhao, Chen, Zhang, Tong, Zwinger, Thomas, Payne, Antony J., Nowicki, Sophie, Abe‐Ouchi, Ayako, Agosta, Cécile, Alexander, Patrick, Albrecht, Torsten, Asay‐Davis, Xylar, Aschwanden, Andy, Barthel, Alice, Bracegirdle, Thomas J., Calov, Reinhard, Chambers, Christopher, Choi, Youngmin, Cullather, Richard, Cuzzone, Joshua, Dumas, Christophe, Edwards, Tamsin L., Felikson, Denis, Fettweis, Xavier, Galton‐Fenzi, Benjamin K., Goelzer, Heiko, Gladstone, Rupert, Golledge, Nicholas R., Gregory, Jonathan M., Greve, Ralf, Hattermann, Tore, Hoffman, Matthew J., Humbert, Angelika, Huybrechts, Philippe, Jourdain, Nicolas C., Kleiner, Thomas, Munneke, Peter Kuipers, Larour, Eric, Le clec'h, Sebastien, Lee, Victoria, Leguy, Gunter, Lipscomb, William H., Little, Christopher M., Lowry, Daniel P., Morlighem, Mathieu, Nias, Isabel, Pattyn, Frank, Pelle, Tyler, Price, Stephen F., Quiquet, Aurélien, Reese, Ronja, Rückamp, Martin, Schlegel, Nicole‐Jeanne, Seroussi, Hélène, Shepherd, Andrew, Simon, Erika, Slater, Donald, Smith, Robin S., Straneo, Fiammetta, Sun, Sainan, Tarasov, Lev, Trusel, Luke D., Van Breedam, Jonas, van de Wal, Roderik, van den Broeke, Michiel, Winkelmann, Ricarda, Zhao, Chen, Zhang, Tong, and Zwinger, Thomas

Abstract

Projections of the sea level contribution from the Greenland and Antarctic ice sheets 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 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.

Published
2021

44. Future Sea Level Change Under Coupled Model Intercomparison Project Phase 5 and Phase 6 Scenarios From the Greenland and Antarctic Ice Sheets

Author

Payne, Antony J, Nowicki, Sophie, Abe‐Ouchi, Ayako, Agosta, Cécile, Alexander, Patrick, Albrecht, Torsten, Asay‐Davis, Xylar, Aschwanden, Andy, Barthel, Alice, Bracegirdle, Thomas J, Calov, Reinhard, Chambers, Christopher, Choi, Youngmin, Cullather, Richard, Cuzzone, Joshua, Dumas, Christophe, Edwards, Tamsin L, Felikson, Denis, Fettweis, Xavier, Galton‐Fenzi, Benjamin K, Goelzer, Heiko, Gladstone, Rupert, Golledge, Nicholas R, Gregory, Jonathan M, Greve, Ralf, Hattermann, Tore, Hoffman, Matthew J, Humbert, Angelika, Huybrechts, Philippe, Jourdain, Nicolas C, Kleiner, Thomas, Munneke, Peter Kuipers, Larour, Eric, Le clec'h, Sebastien, Lee, Victoria, Leguy, Gunter, Lipscomb, William H, Little, Christopher M, Lowry, Daniel P, Morlighem, Mathieu, Nias, Isabel, Pattyn, Frank, Pelle, Tyler, Price, Stephen F, Quiquet, Aurélien, Reese, Ronja, Rückamp, Martin, Schlegel, Nicole‐Jeanne, Seroussi, Hélène, Shepherd, Andrew, Simon, Erika, Slater, Donald, Smith, Robin S, Straneo, Fiammetta, Sun, Sainan, Tarasov, Lev, Trusel, Luke D, Van Breedam, Jonas, Wal, Roderik, Broeke, Michiel, Winkelmann, Ricarda, Zhao, Chen, Zhang, Tong, Zwinger, Thomas, Payne, Antony J, Nowicki, Sophie, Abe‐Ouchi, Ayako, Agosta, Cécile, Alexander, Patrick, Albrecht, Torsten, Asay‐Davis, Xylar, Aschwanden, Andy, Barthel, Alice, Bracegirdle, Thomas J, Calov, Reinhard, Chambers, Christopher, Choi, Youngmin, Cullather, Richard, Cuzzone, Joshua, Dumas, Christophe, Edwards, Tamsin L, Felikson, Denis, Fettweis, Xavier, Galton‐Fenzi, Benjamin K, Goelzer, Heiko, Gladstone, Rupert, Golledge, Nicholas R, Gregory, Jonathan M, Greve, Ralf, Hattermann, Tore, Hoffman, Matthew J, Humbert, Angelika, Huybrechts, Philippe, Jourdain, Nicolas C, Kleiner, Thomas, Munneke, Peter Kuipers, Larour, Eric, Le clec'h, Sebastien, Lee, Victoria, Leguy, Gunter, Lipscomb, William H, Little, Christopher M, Lowry, Daniel P, Morlighem, Mathieu, Nias, Isabel, Pattyn, Frank, Pelle, Tyler, Price, Stephen F, Quiquet, Aurélien, Reese, Ronja, Rückamp, Martin, Schlegel, Nicole‐Jeanne, Seroussi, Hélène, Shepherd, Andrew, Simon, Erika, Slater, Donald, Smith, Robin S, Straneo, Fiammetta, Sun, Sainan, Tarasov, Lev, Trusel, Luke D, Van Breedam, Jonas, Wal, Roderik, Broeke, Michiel, Winkelmann, Ricarda, Zhao, Chen, Zhang, Tong, and Zwinger, Thomas

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.

Published
2021

45. Future sea level change under CMIP5 and CMIP6 scenarios from the Greenland and Antarctic ice sheets

Author

Payne, Antony J., Nowicki, Sophie, Abe-Ouchi, Ayako, Agosta, Cecile, Alexander, Patrick, Albrecht, Torsten, Asay‐Davis, Xylar, Aschwanden, Andy, Barthel, Alice, Bracegirdle, Thomas J., Calov, Reinhard, Chambers, Christopher, Choi, Youngmin, Cullather, Richard, Cuzzone, Joshua, Dumas, Christophe, Edwards, Tamsin L, Felikson, Denis, Fettweis, Xavier, Galton‐Fenzi, Benjamin K., Goelzer, Heiko, Gladstone, Rupert R.M., Golledge, Nicholas R., Gregory, Jonathan M., Greve, Ralf, Hattermann, Tore, Hoffman, Matthew J., Humbert, Angelika, Huybrechts, Philippe, Jourdain, Nicolas C., Kleiner, Thomas, Munneke, Peter Kuipers, Larour, Eric, Le clec'h, Sebastien, Lee, Victoria, Leguy, Gunter, Lipscomb, William H., Little, Christopher M., Lowry, Daniel P., Morlighem, Mathieu, Nias, Isabel, Pattyn, Frank, Pelle, Tyler, Price, Stephen F., Quiquet, Aurelien, Reese, Ronja, Rückamp, Martin, Schlegel, Nicole-Jeanne, Seroussi, Helene, Shepherd, Andrew, Simon, Erika, Slater, Donald, Smith, Robin R.S., Straneo, Fiammetta, Sun, Sainan, Tarasov, Lev, Trusel, Luke D., Van Breedam, Jonas, van de Wal, Roderik S W, Van den Broeke, Michiel, Winkelmann, Ricarda, Zhao, Cheng, Zhang, Tong, Zwinger, Thomas, Payne, Antony J., Nowicki, Sophie, Abe-Ouchi, Ayako, Agosta, Cecile, Alexander, Patrick, Albrecht, Torsten, Asay‐Davis, Xylar, Aschwanden, Andy, Barthel, Alice, Bracegirdle, Thomas J., Calov, Reinhard, Chambers, Christopher, Choi, Youngmin, Cullather, Richard, Cuzzone, Joshua, Dumas, Christophe, Edwards, Tamsin L, Felikson, Denis, Fettweis, Xavier, Galton‐Fenzi, Benjamin K., Goelzer, Heiko, Gladstone, Rupert R.M., Golledge, Nicholas R., Gregory, Jonathan M., Greve, Ralf, Hattermann, Tore, Hoffman, Matthew J., Humbert, Angelika, Huybrechts, Philippe, Jourdain, Nicolas C., Kleiner, Thomas, Munneke, Peter Kuipers, Larour, Eric, Le clec'h, Sebastien, Lee, Victoria, Leguy, Gunter, Lipscomb, William H., Little, Christopher M., Lowry, Daniel P., Morlighem, Mathieu, Nias, Isabel, Pattyn, Frank, Pelle, Tyler, Price, Stephen F., Quiquet, Aurelien, Reese, Ronja, Rückamp, Martin, Schlegel, Nicole-Jeanne, Seroussi, Helene, Shepherd, Andrew, Simon, Erika, Slater, Donald, Smith, Robin R.S., Straneo, Fiammetta, Sun, Sainan, Tarasov, Lev, Trusel, Luke D., Van Breedam, Jonas, van de Wal, Roderik S W, Van den Broeke, Michiel, Winkelmann, Ricarda, Zhao, Cheng, Zhang, Tong, and Zwinger, Thomas

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., SCOPUS: ar.j, info:eu-repo/semantics/published

Published
2021

46. Future sea level contribution from Antarcticainferred from CMIP5 model forcing and itsdependence on precipitation ansatz

Author

Rodehacke, Christian B., Pfeiffer, Madlene, Semmler, Tido, Gurses, Özgür, and Kleiner, Thomas

Abstract

Various observational estimates indicate growing mass loss at Antarctica's margins but also heavier precipitation across the continent. In the future, heavier precipitation fallen on Antarctica will counteract any stronger iceberg discharge and increased basal melting of floating ice shelves driven by a warming ocean. Here, we use from nine CMIP5 models future projections, ranging from strong mitigation efforts to business-as-usual, to run an ensemble of ice-sheet simulations. We test, how the precipitation boundary condition determines Antarctica's sea-level contribution. The spatial and temporal varying climate forcings drive ice-sheet simulations. Hence, our ensemble inherits all spatial and temporal climate patterns, which is in contrast to a spatial mean forcing. Regardless of the applied boundary condition and forcing, some areas will lose ice in the future, such as the glaciers from the West Antarctic Ice Sheet draining into the Amundsen Sea. In general the simulated ice-sheet thickness grows in a broad marginal strip, where incoming storms deliver topographically controlled precipitation. This strip shows the largest ice thickness differences between the applied precipitation boundary conditions too. On average Antarctica's ice mass shrinks for all future scenarios if the precipitation is scaled by the spatial temperature anomalies coming from the CMIP5 models. In this approach, we use the relative precipitation increment per degree warming as invariant scaling constant. In contrast, Antarctica gains mass in our simulations if we apply the simulated precipitation anomalies of the CMIP5 models directly. Here, the scaling factors show a distinct spatial pattern across Antarctica. Furthermore, the diagnosed mean scaling across all considered climate forcings is larger than the values deduced from ice cores. In general, the scaling is higher across the East Antarctic Ice Sheet, lower across the West Antarctic Ice Sheet, and lowest around the Siple Coast. The latter is located on the east side of the Ross Ice Shelf.

Published
2020
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47. Greenland's glacier tidal response and ice sheet motion  

Author

Christmann, Julia, primary, Helm, Veit, additional, Khan, Shfaqat Abbas, additional, Kleiner, Thomas, additional, Müller, Ralf, additional, Morlighem, Mathieu, additional, Neckel, Niklas, additional, Rückamp, Martin, additional, Steinhage, Daniel, additional, Zeising, Ole, additional, and Humbert, Angelika, additional

Published
2021
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49. ISMIP6 Antarctica: a multi-model ensemble of the Antarctic ice sheet evolution over the 21st century

Author

Seroussi, Helene, Nowicki, Sophie, Payne, Antony J., Goelzer, Heiko, Lipscomb, William H., Abe Ouchi, Ayako, Agosta, Cecile, Albrecht, Torsten, Asay-Davis, Xylar, Barthel, Alice, Calov, Reinhard, Cullather, Richard, Dumas, Christophe, Gladstone, Rupert, Golledge, Nicholas, Gregory, Jonathan M., Greve, Ralf, Hatterman, Tore, Hoffman, Matthew J., Humbert, Angelika, Huybrechts, Philippe, Jourdain, Nicolas C., Kleiner, Thomas, Larour, Eric, Leguy, Gunter R., Lowry, Daniel P., Little, Chistopher M., Morlighem, Mathieu, Pattyn, Frank, Pelle, Tyler, Price, Stephen F., Quiquet, Aurélien, Reese, Ronja, Schlegel, Nicole-Jeanne, Shepherd, Andrew, Simon, Erika, Smith, Robin S., Straneo, Fiammetta, Sun, Sainan, Trusel, Luke D., Breedam, Jonas, Wal, Roderik S. W., Winkelmann, Ricarda, Zhao, Chen, Zhang, Tong, and Zwinger, Thomas

Abstract

Ice flow models of the Antarctic ice sheet are commonly used to simulate its future evolution in response to different climate scenarios and inform on the mass loss that would contribute to future sea level rise. However, there is currently no consensus on estimated the future mass balance of the ice sheet, primarily because of differences in the representation of physical processes and the forcings employed. This study presents results from 18 simulations from 15 international groups focusing on the evolution of the Antarctic ice sheet during the period 2015–2100, forced with different scenarios from the Coupled Model Intercomparison Project Phase 5 (CMIP5) representative of the spread in climate model results. The contribution of the Antarctic ice sheet in response to increased warming during this period varies between −7.8 and 30.0 cm of Sea Level Equivalent (SLE). The evolution of the West Antarctic Ice Sheet varies widely among models, with an overall mass loss up to 21.0 cm SLE in response to changes in oceanic conditions. East Antarctica mass change varies between −6.5 and 16.5 cm SLE, with a significant increase in surface mass balance outweighing the increased ice discharge under most RCP 8.5 scenario forcings. The inclusion of ice shelf collapse, here assumed to be caused by large amounts of liquid water ponding at the surface of ice shelves, yields an additional mass loss of 8 mm compared to simulations without ice shelf collapse. The largest sources of uncertainty come from the ocean-induced melt rates, the calibration of these melt rates based on oceanic conditions taken outside of ice shelf cavities and the ice sheet dynamic response to these oceanic changes. Results under RCP 2.6 scenario based on two CMIP5 AOGCMs show an overall mass loss of 10 mm SLE compared to simulations done under present-day conditions, with limited mass gain in East Antarctica.

Published
2020
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50. ISMIP6 Antarctica

Author

Seroussi, Helene, Nowicki, Sophie, Payne, Antony J., Goelzer, Heiko, Lipscomb, William H., Abe-Ouchi, Ayako, Agosta, Cecile, Albrecht, Torsten, Asay-Davis, Xylar, Barthel, Alice, Calov, Reinhard, Cullather, Richard, Dumas, Christophe, Galton-Fenzi, Benjamin K., Gladstone, Rupert, Golledge, Nicholas R., Gregory, Jonathan M., Greve, Ralf, Hattermann, Tore, Hoffman, Matthew J., Humbert, Angelika, Huybrechts, Philippe, Jourdain, Nicolas C., Kleiner, Thomas, Larour, Eric, Leguy, Gunter R., Lowry, Daniel P., Little, Chistopher M., Morlighem, Mathieu, Pattyn, Frank, Pelle, Tyler, Price, Stephen F., Quiquet, Aurelien, Reese, Ronja, Schlegel, Nicole-Jeanne, Shepherd, Andrew, Simon, Erika, Smith, Robin S., Straneo, Fiammetta, Sun, Sainan, Trusel, Luke D., Van Breedam, Jonas, van de Wal, Roderik S. W., Winkelmann, Ricarda (Prof. Dr.), Zhao, Chen, Zhang, Tong, and Zwinger, Thomas

Subjects
Institut für Physik und Astronomie, ddc:530
Abstract

Ice flow models of the Antarctic ice sheet are commonly used to simulate its future evolution in response to different climate scenarios and assess the mass loss that would contribute to future sea level rise. However, there is currently no consensus on estimates of the future mass balance of the ice sheet, primarily because of differences in the representation of physical processes, forcings employed and initial states of ice sheet models. This study presents results from ice flow model simulations from 13 international groups focusing on the evolution of the Antarctic ice sheet during the period 2015-2100 as part of the Ice Sheet Model Intercomparison for CMIP6 (ISMIP6). They are forced with outputs from a subset of models from the Coupled Model Intercomparison Project Phase 5 (CMIP5), representative of the spread in climate model results. Simulations of the Antarctic ice sheet contribution to sea level rise in response to increased warming during this period varies between 7:8 and 30.0 cm of sea level equivalent (SLE) under Representative Concentration Pathway (RCP) 8.5 scenario forcing. These numbers are relative to a control experiment with constant climate conditions and should therefore be added to the mass loss contribution under climate conditions similar to present-day conditions over the same period. The simulated evolution of the West Antarctic ice sheet varies widely among models, with an overall mass loss, up to 18.0 cm SLE, in response to changes in oceanic conditions. East Antarctica mass change varies between 6 :1 and 8.3 cm SLE in the simulations, with a significant increase in surface mass balance outweighing the increased ice discharge under most RCP 8.5 scenario forcings. The inclusion of ice shelf collapse, here assumed to be caused by large amounts of liquid water ponding at the surface of ice shelves, yields an additional simulated mass loss of 28mm compared to simulations without ice shelf collapse. The largest sources of uncertainty come from the climate forcing, the ocean-induced melt rates, the calibration of these melt rates based on oceanic conditions taken outside of ice shelf cavities and the ice sheet dynamic response to these oceanic changes. Results under RCP 2.6 scenario based on two CMIP5 climate models show an additional mass loss of 0 and 3 cm of SLE on average compared to simulations done under present-day conditions for the two CMIP5 forcings used and display limited mass gain in East Antarctica.

Published
2020

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