Articles | Volume 18, issue 4
https://doi.org/10.5194/tc-18-1863-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/tc-18-1863-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
22 Apr 2024
Research article |
| 22 Apr 2024
| 22 Apr 2024
Geometric amplification and suppression of ice-shelf basal melt in West Antarctica
Department of Geography and Environmental Sciences, Northumbria University, Newcastle upon Tyne, UK
Kaitlin Naughten
British Antarctic Survey, Cambridge, UK
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Pine Island Glacier has contributed more to sea-level rise over the past decades than any other glacier in Antarctica. Ice-flow modelling studies have shown that it can undergo periods of rapid mass loss, but no study has shown that these future changes could cross a tipping point and therefore be effectively irreversible. Here, we assess the stability of Pine Island Glacier, quantifying the changes in ocean temperatures required to cross future tipping points using statistical methods.
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We used satellite observations and numerical simulations of Pine Island Glacier, West Antarctica, between 1996 and 2016 to show that the recent increase in its flow speed can only be reproduced by computer models if stringent assumptions are made about the material properties of the ice and its underlying bed. These assumptions are not commonly adopted in ice flow modelling, and our results therefore have implications for future simulations of Antarctic ice flow and sea level projections.
Cited articles
Adusumilli, S., Fricker, H. A., Medley, B., Padman, L., and Siegfried, M. R.: Interannual variations in meltwater input to the Southern Ocean from Antarctic ice shelves, Nat. Geosci., 13, 616–620, https://doi.org/10.1038/s41561-020-0616-z, 2018. a, b, c, d
Arthern, R. J. and Williams, C. R.: The sensitivity of West Antarctica to the submarine melting feedback, Geophys. Res. Lett., 44, 2352–2359, https://doi.org/10.1002/2017GL072514, 2017. a, b
Bamber, J. L., Gomez-Dans, J. L., and Griggs, J. A.: A new 1 km digital elevation model of the Antarctic derived from combined satellite radar and laser data – Part 1: Data and methods, The Cryosphere, 3, 101–111, https://doi.org/10.5194/tc-3-101-2009, 2009. a
Barnes, J. M., Dias dos Santos, T., Goldberg, D., Gudmundsson, G. H., Morlighem, M., and De Rydt, J.: The transferability of adjoint inversion products between different ice flow models, The Cryosphere, 15, 1975–2000, https://doi.org/10.5194/tc-15-1975-2021, 2021. a
Bradley, A. T., Bett, D. T., Dutrieux, P., De Rydt, J., and Holland, P. R.: The Influence of Pine Island Ice Shelf Calving on Basal Melting, J. Geophys. Res.-Oceans, 127, e2022JC018621, https://doi.org/10.1029/2022JC018621, 2022. a, b, c, d
Cornford, S. L., Martin, D. F., Lee, V., Payne, A. J., and Ng, E. G.: Adaptive mesh refinement versus subgrid friction interpolation in simulations of Antarctic ice dynamics, Ann. Glaciol., 57, 1–9, https://doi.org/10.1017/aog.2016.13, 2016. a
Davison, B. J., Hogg, A. E., Rigby, R., Veldhuijsen, S., van Wessem, J. M., van den Broeke, M. R., Holland, P. R., Selley, H. L., and Dutrieux, P.: Sea level rise from West Antarctic mass loss significantly modified by large snowfall anomalies, Nat. Commun., 14, 1479, https://doi.org/10.1038/s41467-023-36990-3, 2023. a
Depoorter, M. A., Bamber, J. L., Griggs, J. A., Lenaerts, J. T., Ligtenberg, S. R., Van Den Broeke, M. R., and Moholdt, G.: Calving fluxes and basal melt rates of Antarctic ice shelves, Nature, 502, 89–92, https://doi.org/10.1038/nature12567, 2013. a
De Rydt, J.: Model output for “Geometric amplification and suppression of ice-shelf basal melt in West Antarctica” (Version v1), Zenodo [data set], https://doi.org/10.5281/zenodo.10778033, 2024. a, b
De Rydt, J. and Gudmundsson, G. H.: Coupled ice shelf-ocean modeling and complex grounding line retreat from a seabed ridge, J. Geophys. Res. Res.-Earth Surf., 121, 865–880, https://doi.org/10.1002/2015JF003791, 2016. a, b, c
De Rydt, J., Holland, P. R., Dutrieux, P., and Jenkins, A.: Geometric and oceanographic controls on melting beneath Pine Island Glacier, J. Geophys. Res.-Oceans, 119, 2420–2438, https://doi.org/10.1002/2013JC009513, 2014. a
De Rydt, J., Reese, R., Paolo, F. S., and Gudmundsson, G. H.: Drivers of Pine Island Glacier speed-up between 1996 and 2016, The Cryosphere, 15, 113–132, https://doi.org/10.5194/tc-15-113-2021, 2021. a, b, c, d
Dutrieux, P., De Rydt, J., Jenkins, A., Holland, P. R., Ha, H. K., Lee, S. H., Steig, E. J., Ding, Q., Abrahamsen, E. P., and Schröder, M.: Strong sensitivity of pine Island ice-shelf melting to climatic variability, Science, 343, 174–178, https://doi.org/10.1126/science.1244341, 2014. a, b, c, d
Edwards, T. L., Nowicki, S., Marzeion, B., Hock, R., Goelzer, H., Seroussi, H., Jourdain, N. C., Slater, D. A., Turner, F. E., Smith, C. J., McKenna, C. M., Simon, E., Abe-Ouchi, A., Gregory, J. M., Larour, E., Lipscomb, W. H., Payne, A. J., Shepherd, A., Agosta, C., Alexander, P., Albrecht, T., Anderson, B., Asay-Davis, X., Aschwanden, A., Barthel, A., Bliss, A., Calov, R., Chambers, C., Champollion, N., Choi, Y., Cullather, R., Cuzzone, J., Dumas, C., Felikson, D., Fettweis, X., Fujita, K., Galton-Fenzi, B. K., Gladstone, R., Golledge, N. R., Greve, R., Hattermann, T., Hoffman, M. J., Humbert, A., Huss, M., Huybrechts, P., Immerzeel, W., Kleiner, T., Kraaijenbrink, P., Le clec’h, S., Lee, V., Leguy, G. R., Little, C. M., Lowry, D. P., Malles, J. H., Martin, D. F., Maussion, F., Morlighem, M., O’Neill, J. F., Nias, I., Pattyn, F., Pelle, T., Price, S. F., Quiquet, A., Radić, V., Reese, R., Rounce, D. R., Rückamp, M., Sakai, A., Shafer, C., Schlegel, N. J., Shannon, S., Smith, R. S., Straneo, F., Sun, S., Tarasov, L., Trusel, L. D., Van Breedam, J., van de Wal, R., van den Broeke, M., Winkelmann, R., Zekollari, H., Zhao, C., Zhang, T., and Zwinger, T.: Projected land ice contributions to twenty-first-century sea level rise, Nature, 593, 74–82, https://doi.org/10.1038/s41586-021-03302-y, 2021. a, b
Goldberg, D. N. and Holland, P. R.: The Relative Impacts of Initialization and Climate Forcing in Coupled Ice Sheet-Ocean Modeling: Application to Pope, Smith, and Kohler Glaciers, J. Geophys. Res.-Earth Surf., 127, e2021JF006570, https://doi.org/10.1029/2021JF006570, 2022. a, b
Goldberg, D. N., Gourmelen, N., Kimura, S., Millan, R., and Snow, K.: How Accurately Should We Model Ice Shelf Melt Rates?, Geophys. Res. Lett., 46, 189–199, https://doi.org/10.1029/2018GL080383, 2019. a
Gourmelen, N., Goldberg, D. N., Snow, K., Henley, S. F., Bingham, R. G., Kimura, S., Hogg, A. E., Shepherd, A., Mouginot, J., Lenaerts, J. T., Ligtenberg, S. R., and van de Berg, W. J.: Channelized Melting Drives Thinning Under a Rapidly Melting Antarctic Ice Shelf, Geophys. Res. Lett., 44, 9796–9804, https://doi.org/10.1002/2017GL074929, 2017. a
Gudmundsson, G. H.: GHilmarG/UaSource: Ua2019b, Zenodo [code], https://doi.org/10.5281/zenodo.3706623, 2020. a, b
Gudmundsson, G. H., Krug, J., Durand, G., Favier, L., and Gagliardini, O.: The stability of grounding lines on retrograde slopes, The Cryosphere, 6, 1497–1505, https://doi.org/10.5194/tc-6-1497-2012, 2012. a
Gudmundsson, G. H., Paolo, F. S., Adusumilli, S., and Fricker, H. A.: Instantaneous Antarctic ice sheet mass loss driven by thinning ice shelves, Geophys. Res. Lett., 46, 13903–13909, https://doi.org/10.1029/2019GL085027, 2019. a, b
Haseloff, M. and Sergienko, O. V.: The effect of buttressing on grounding line dynamics, J. Glaciol., 64, 417–431, https://doi.org/10.1017/jog.2018.30, 2018. a
Heywood, K. J., Biddle, L. C., Boehme, L., Fedak, M., Dutrieux, P., Jenkins, A., Kaiser, J., Mallett, H., Jones, R. W., Naveira Garabato, A. C., Renfrew, I. A., Stevens, D. P., and Webber, B. G.: Between the devil and the deep blue sea: The role of the Amundsen Sea continental shelf in exchanges between ocean and ice shelves, Oceanography, 29, 118–129, https://doi.org/10.5670/oceanog.2016.104, 2016. a
Holland, D. M. and Jenkins, A.: Modeling thermodynamic ice-ocean interactions at the base of an ice shelf, J. Phys. Oceanogr., 29, 1787–1800, https://doi.org/10.1175/1520-0485(1999)029<1787:mtioia>2.0.co;2, 1999. a
Holland, P. R., Jenkins, A., and Holland, D. M.: The response of Ice shelf basal melting to variations in ocean temperature, J. Climate, 21, 2558–2572, https://doi.org/10.1175/2007JCLI1909.1, 2008. a, b, c
Holland, P. R., O'Connor, G. K., Bracegirdle, T. J., Dutrieux, P., Naughten, K. A., Steig, E. J., Schneider, D. P., Jenkins, A., and Smith, J. A.: Anthropogenic and internal drivers of wind changes over the Amundsen Sea, West Antarctica, during the 20th and 21st centuries, The Cryosphere, 16, 5085–5105, https://doi.org/10.5194/tc-16-5085-2022, 2022. a
Holland, P. R., Bevan, S. L., and Luckman, A. J.: Strong Ocean Melting Feedback During the Recent Retreat of Thwaites Glacier, Geophys. Res. Lett., 50, e2023GL103088, https://doi.org/10.1029/2023GL103088, 2023. a, b, c
IMBIE Team: Mass balance of the Antarctic Ice Sheet from 1992 to 2017, Nature, 558, 219–222, https://doi.org/10.1038/s41586-018-0179-y, 2018. a, b
Jacobs, S. S. and Hellmer, H. H.: Freshening Could Come From Other Melting Ice in the, Observatory, 23, 957–960, 1996. a
Jenkins, A.: A one-dimensional model of ice shelf-ocean interaction, J. Geophys. Res., 96, 20671, https://doi.org/10.1029/91jc01842, 1991. a
Jenkins, A. and Bombosch, A.: Modeling the effects of frazil ice crystals on the dynamics and thermodynamics of Ice Shelf Water plumes, J. Geophys. Res., 100, 6967, https://doi.org/10.1029/94JC03227, 1995. a
Jenkins, A., Nicholls, K. W., and Corr, H. F.: Observation and parameterization of ablation at the base of Ronne Ice Ahelf, Antarctica, J. Phys. Oceanogr., 40, 2298–2312, https://doi.org/10.1175/2010JPO4317.1, 2010. a
Jenkins, A., Dutrieux, P., Jacobs, S., Steig, E. J., Gudmundsson, G. H., Smith, J., and Heywood, K. J.: Decadal ocean forcing and Antarctic ice sheet response: Lessons from the Amundsen Sea, Oceanography, 29, 106–117, https://doi.org/10.5670/oceanog.2016.103, 2016. a
Jenkins, A., Shoosmith, D., Dutrieux, P., Jacobs, S., Kim, T. W., Lee, S. H., Ha, H. K., and Stammerjohn, S.: West Antarctic Ice Sheet retreat in the Amundsen Sea driven by decadal oceanic variability, Nat. Geosci., 11, 733–738, https://doi.org/10.1038/s41561-018-0207-4, 2018. a, b, c
Joughin, I., Smith, B. E., and Schoof, C. G.: Regularized Coulomb Friction Laws for Ice Sheet Sliding: Application to Pine Island Glacier, Antarctica, Geophys. Res. Lett., 46, 4764–4771, https://doi.org/10.1029/2019GL082526, 2019. a
Joughin, I., Shapero, D., Smith, B., Dutrieux, P., and Barham, M.: Ice-shelf retreat drives recent Pine Island Glacier speedup, Sci. Adv., 7, 3080–3091, https://doi.org/10.1126/sciadv.abg3080, 2021. a, b
Jourdain, N. C., Mathiot, P., Merino, N., Durand, G. G., Le Sommer, J., Spence, P., Dutrieux, P., Madec, G., Sommer, J. L., Spence, P., Dutrieux, P., and Madec, G.: Ocean circulation and sea-ice thinning induced by melting ice shelves in the Amundsen Sea, J. Geophys. Res.-Oceans, 122, 2550–2573, https://doi.org/10.1002/2016JC012509, 2017. a
Jourdain, N. C., Mathiot, P., Burgard, C., Caillet, J., and Kittel, C.: Ice Shelf Basal Melt Rates in the Amundsen Sea at the End of the 21st Century, Geophys. Res. Lett., 49, e2022GL100629, https://doi.org/10.1029/2022GL100629, 2022. a, b, c
Kimura, S., Jenkins, A., Regan, H., Holland, P. R., Assmann, K. M., Whitt, D. B., Van Wessem, M., van de Berg, W. J., Reijmer, C. H., and Dutrieux, P.: Oceanographic Controls on the Variability of Ice-Shelf Basal Melting and Circulation of Glacial Meltwater in the Amundsen Sea Embayment, Antarctica, J. Geophys. Res.-Oceans, 122, 10131–10155, https://doi.org/10.1002/2017JC012926, 2017. a, b, c, d, e, f, g
Lazeroms, W. M., Jenkins, A., Rienstra, S. W., and Van De Wal, R. S.: An analytical derivation of ice-shelf basal melt based on the dynamics of meltwater plumes, J. Phys. Oceanogr., 49, 917–939, https://doi.org/10.1175/JPO-D-18-0131.1, 2019. a
Lhermitte, S., Sun, S., Shuman, C., Wouters, B., Pattyn, F., Wuite, J., Berthier, E., and Nagler, T.: Damage accelerates ice shelf instability and mass loss in Amundsen Sea Embayment, P. Natl. Acad. Sci. USA, 117, 24735–24741, https://doi.org/10.1073/pnas.1912890117, 2020. a
Losch, M.: Modeling ice shelf cavities in a z coordinate ocean general circulation model, J. Geophys. Res.-Oceans, 113, https://doi.org/10.1029/2007JC004368, 2008. a, b
Macayeal, D. R.: The basal stress distribution of ice stream E, Antarctica, inferred by control methods, J. Geophys. Res., 97, 595–603, https://doi.org/10.1029/91JB02454, 1992. a
Marshall, J., Hill, C., Perelman, L., and Adcroft, A.: NON-HYDRQ, 102, 5733–5752, 1997. a
Milillo, P., Rignot, E., Rizzoli, P., Scheuchl, B., Mouginot, J., Bueso-Bello, J., and Prats-Iraola, P.: Heterogeneous retreat and ice melt of thwaites glacier, West Antarctica, Sci. Adv., 5, 1–9, https://doi.org/10.1126/sciadv.aau3433, 2019. a
Milillo, P., Rignot, E., Rizzoli, P., Scheuchl, B., Mouginot, J., Bueso-Bello, J. L., Prats-Iraola, P., and Dini, L.: Rapid glacier retreat rates observed in West Antarctica, Nat. Geosci., 15, 48–53, https://doi.org/10.1038/s41561-021-00877-z, 2022. a
Morlighem, M., Rignot, E., Binder, T., Blankenship, D., Drews, R., Eagles, G., Eisen, O., Ferraccioli, F., Forsberg, R., Fretwell, P., Goel, V., Greenbaum, J. S., Gudmundsson, H., Guo, J., Helm, V., Hofstede, C., Howat, I., Humbert, A., Jokat, W., Karlsson, N. B., Lee, W. S., Matsuoka, K., Millan, R., Mouginot, J., Paden, J., Pattyn, F., Roberts, J., Rosier, S., Ruppel, A., Seroussi, H., Smith, E. C., Steinhage, D., Sun, B., Broeke, M. R. d., Ommen, T. D., Wessem, M. v., and Young, D. A.: Deep glacial troughs and stabilizing ridges unveiled beneath the margins of the Antarctic ice sheet, Nat. Geosci., 13, 132–137, https://doi.org/10.1038/s41561-019-0510-8, 2020. a, b, c
Mouginot, J., Rignot, E., and Scheuchl, B.: Sustained increase in ice discharge from the Amundsen Sea Embayment, West Antarctica, from 1973 to 2013, Geophys. Res. Lett., 41, 1576–1584, https://doi.org/10.1002/2013GL059069, 2014. a
Naughten, K. A. and De Rydt, J.: Ua-MITgcm PTDC configuration (Version 1.2), Zenodo [code], https://doi.org/10.5281/zenodo.7989869, 2023. a, b, c
Naughten, K. A., Meissner, K. J., Galton-Fenzi, B. K., England, M. H., Timmermann, R., and Hellmer, H. H.: Future Projections of Antarctic Ice Shelf Melting Based on CMIP5 Scenarios, J. Climate, 31, 5243–5261, https://doi.org/10.1175/JCLI-D-17-0854.s1, 2018. a
Naughten, K. A., De Rydt, J., Rosier, S. H., Jenkins, A., Holland, P. R., and Ridley, J. K.: Two-timescale response of a large Antarctic ice shelf to climate change, Nat. Commun., 12, 1991, https://doi.org/10.1038/s41467-021-22259-0, 2021. a
Naughten, K. A., Holland, P. R., and De Rydt, J.: Unavoidable future increase in West Antarctic ice-shelf melting over the twenty-first century, Nat. Clim. Change, 13, 1222–1228, https://doi.org/10.1038/s41558-023-01818-x, 2023. a
Otosaka, I. N., Shepherd, A., Ivins, E. R., Schlegel, N.-J., Amory, C., van den Broeke, M. R., Horwath, M., Joughin, I., King, M. D., Krinner, G., Nowicki, S., Payne, A. J., Rignot, E., Scambos, T., Simon, K. M., Smith, B. E., Sørensen, L. S., Velicogna, I., Whitehouse, P. L., A, G., Agosta, C., Ahlstrøm, A. P., Blazquez, A., Colgan, W., Engdahl, M. E., Fettweis, X., Forsberg, R., Gallée, H., Gardner, A., Gilbert, L., Gourmelen, N., Groh, A., Gunter, B. C., Harig, C., Helm, V., Khan, S. A., Kittel, C., Konrad, H., Langen, P. L., Lecavalier, B. S., Liang, C.-C., Loomis, B. D., McMillan, M., Melini, D., Mernild, S. H., Mottram, R., Mouginot, J., Nilsson, J., Noël, B., Pattle, M. E., Peltier, W. R., Pie, N., Roca, M., Sasgen, I., Save, H. V., Seo, K.-W., Scheuchl, B., Schrama, E. J. O., Schröder, L., Simonsen, S. B., Slater, T., Spada, G., Sutterley, T. C., Vishwakarma, B. D., van Wessem, J. M., Wiese, D., van der Wal, W., and Wouters, B.: Mass balance of the Greenland and Antarctic ice sheets from 1992 to 2020, Earth Syst. Sci. Data, 15, 1597–1616, https://doi.org/10.5194/essd-15-1597-2023, 2023. a
Paolo, F. S., Fricker, H. A., and Padman, L.: Volume loss from Antarctic ice shelves is accelerating, Science, 348, 327–331, https://doi.org/10.1126/science.aaa0940, 2015. a
Paolo, F. S., Gardner, A. S., Greene, C. A., Nilsson, J., Schodlok, M. P., Schlegel, N.-J., and Fricker, H. A.: Widespread slowdown in thinning rates of West Antarctic ice shelves, The Cryosphere, 17, 3409–3433, https://doi.org/10.5194/tc-17-3409-2023, 2023. a, b
Patmore, R. D., Holland, P. R., Munday, D. R., Naveira Garabato, A. C., Stevens, D. P., Meredith, M. P., Patmore, R. D., Holland, P. R., Munday, D. R., Garabato, A. C. N., Stevens, D. P., and Meredith, M. P.: Topographic Control of Southern Ocean Gyres and the Antarctic Circumpolar Current: A Barotropic Perspective, J. Phys. Oceanogr., 49, 3221–3244, https://doi.org/10.1175/JPO-D-19-0083.1, 2019. a, b
Pattyn, F., Schoof, C., Perichon, L., Hindmarsh, R. C. A., Bueler, E., de Fleurian, B., Durand, G., Gagliardini, O., Gladstone, R., Goldberg, D., Gudmundsson, G. H., Huybrechts, P., Lee, V., Nick, F. M., Payne, A. J., Pollard, D., Rybak, O., Saito, F., and Vieli, A.: Results of the Marine Ice Sheet Model Intercomparison Project, MISMIP, The Cryosphere, 6, 573–588, https://doi.org/10.5194/tc-6-573-2012, 2012. a
Pedersen, F. B.: Dense bottom currents in rotating ocean, J. Hydraul. Div. Am. Soc. Civ. Eng., 106, 1291–1308, 1980. a
Pegler, S. S.: Marine ice sheet dynamics: The impacts of ice-shelf buttressing, J. Fluid Mech., 857, 605–647, https://doi.org/10.1017/jfm.2018.741, 2018. a
Pritchard, H. D., Ligtenberg, S. R., Fricker, H. A., Vaughan, D. G., Van Den Broeke, M. R., and Padman, L.: Antarctic ice-sheet loss driven by basal melting of ice shelves, Nature, 484, 502–505, https://doi.org/10.1038/nature10968, 2012. a
Reese, R., Garbe, J., Hill, E. A., Urruty, B., Naughten, K. A., Gagliardini, O., Durand, G., Gillet-Chaulet, F., Gudmundsson, G. H., Chandler, D., Langebroek, P. M., and Winkelmann, R.: The stability of present-day Antarctic grounding lines – Part 2: Onset of irreversible retreat of Amundsen Sea glaciers under current climate on centennial timescales cannot be excluded, The Cryosphere, 17, 3761–3783, https://doi.org/10.5194/tc-17-3761-2023, 2023. a
Rignot, E., Thomas, R. H., Kanagaratnam, P., Casassa, G., Frederick, E., Gogineni, S., Krabill, W., Rivera, A., Russell, R., Sonntag, J., Swift, R., and Yungel, J.: Improved estimation of the mass balance of glaciers draining into the Amundsen Sea sector of West Antarctica from the CECS/NASA 2002 campaign, Ann. Glaciol., 39, 231–237, https://doi.org/10.3189/172756404781813916, 2004. a
Rignot, E., Mouginot, J., and Scheuchl, B.: MEaSUREs Antarctic Grounding Line from Differential Satellite Radar Interferometry, Version 2, Bouler, Colorado USA, NASA National Snow and Ice Data Center Distributed Active Archive Center [data set], https://doi.org/10.5067/D7GK8F5J8M8R, 2016. a, b
Rignot, E., Mouginot, J., and Scheuchl, B.: MEaSUREs InSAR-Based Antarctica Ice Velocity Map, Version 2, Boulder, Colorado USA, NASA National Snow and Ice Data Center Distributed Active Archive Center [data set], https://doi.org/10.5067/IKBWW4RYHF1Q, 2017. a
Rignot, E., Mouginot, J., Scheuchl, B., Van Den Broeke, M., Van Wessem, M. J., and Morlighem, M.: Four decades of Antarctic ice sheet mass balance from 1979–2017, P. Natl. Acad. Sci. USA, 116, 1095–1103, https://doi.org/10.1073/pnas.1812883116, 2019. a, b, c
Seroussi, H. and Morlighem, M.: Representation of basal melting at the grounding line in ice flow models, The Cryosphere, 12, 3085–3096, https://doi.org/10.5194/tc-12-3085-2018, 2018. a
Seroussi, H., Nowicki, S., Simon, E., Abe-Ouchi, A., Albrecht, T., Brondex, J., Cornford, S., Dumas, C., Gillet-Chaulet, F., Goelzer, H., Golledge, N. R., Gregory, J. M., Greve, R., Hoffman, M. J., Humbert, A., Huybrechts, P., Kleiner, T., Larour, E., Leguy, G., Lipscomb, W. H., Lowry, D., Mengel, M., Morlighem, M., Pattyn, F., Payne, A. J., Pollard, D., Price, S. F., Quiquet, A., Reerink, T. J., Reese, R., Rodehacke, C. B., Schlegel, N.-J., Shepherd, A., Sun, S., Sutter, J., Van Breedam, J., van de Wal, R. S. W., Winkelmann, R., and Zhang, T.: initMIP-Antarctica: an ice sheet model initialization experiment of ISMIP6, The Cryosphere, 13, 1441–1471, https://doi.org/10.5194/tc-13-1441-2019, 2019. a
Seroussi, H., Nowicki, S., Payne, A. J., Goelzer, H., Lipscomb, W. H., Abe-Ouchi, A., Agosta, C., Albrecht, T., Asay-Davis, X., Barthel, A., Calov, R., Cullather, R., Dumas, C., Galton-Fenzi, B. K., Gladstone, R., Golledge, N. R., Gregory, J. M., Greve, R., Hattermann, T., Hoffman, M. J., Humbert, A., Huybrechts, P., Jourdain, N. C., Kleiner, T., Larour, E., Leguy, G. R., Lowry, D. P., Little, C. M., Morlighem, M., Pattyn, F., Pelle, T., Price, S. F., Quiquet, A., Reese, R., Schlegel, N.-J., Shepherd, A., Simon, E., Smith, R. S., Straneo, F., Sun, S., Trusel, L. D., Van Breedam, J., van de Wal, R. S. W., Winkelmann, R., Zhao, C., Zhang, T., and Zwinger, T.: ISMIP6 Antarctica: a multi-model ensemble of the Antarctic ice sheet evolution over the 21st century, The Cryosphere, 14, 3033–3070, https://doi.org/10.5194/tc-14-3033-2020, 2020. a
Shepherd, A., Gilbert, L., Muir, A. S., Konrad, H., McMillan, M., Slater, T., Briggs, K. H., Sundal, A. V., Hogg, A. E., and Engdahl, M. E.: Trends in Antarctic Ice Sheet Elevation and Mass, Geophys. Res. Lett., 46, 8174–8183, https://doi.org/10.1029/2019GL082182, 2019. a
Siahaan, A., Smith, R. S., Holland, P. R., Jenkins, A., Gregory, J. M., Lee, V., Mathiot, P., Payne, A. J. ., Ridley, J. K. ., and Jones, C. G.: The Antarctic contribution to 21st-century sea-level rise predicted by the UK Earth System Model with an interactive ice sheet, The Cryosphere, 16, 4053–4086, https://doi.org/10.5194/tc-16-4053-2022, 2022. a, b
Silvano, A., Holland, P. R., Naughten, K. A., Dragomir, O., Dutrieux, P., Jenkins, A., Si, Y., Stewart, A. L., Peña Molino, B., Janzing, G. W., Dotto, T. S., and Naveira Garabato, A. C.: Baroclinic Ocean Response to Climate Forcing Regulates Decadal Variability of Ice-Shelf Melting in the Amundsen Sea, Geophys. Res. Lett., 49, e2022GL100646, https://doi.org/10.1029/2022GL100646, 2022. a
Smith, B., Fricker, H. A., Gardner, A. S., Medley, B., Nilsson, J., Paolo, F. S., Holschuh, N., Adusumilli, S., Brunt, K., Csatho, B., Harbeck, K., Markus, T., Neumann, T., Siegfried, M. R., and Zwally, H. J.: Pervasive ice sheet mass loss reflects competing ocean and atmosphere processes, Science, 368, 1239–1242, https://doi.org/10.1126/science.aaz5845, 2020. a
Smith, J. A., Andersen, T. J., Shortt, M., Gaffney, A. M., Truffer, M., Stanton, T. P., Bindschadler, R., Dutrieux, P., Jenkins, A., Hillenbrand, C. D., Ehrmann, W., Corr, H. F., Farley, N., Crowhurst, S., and Vaughan, D. G.: Sub-ice-shelf sediments record history of twentieth-century retreat of Pine Island Glacier, Nature, 541, 77–80, https://doi.org/10.1038/nature20136, 2017. a
Surawy-Stepney, T., Hogg, A. E., Cornford, S. L., and Davison, B. J.: Episodic dynamic change linked to damage on the thwaites glacier ice tongue, Nat. Geosci., 16, 37–43, https://doi.org/10.1038/s41561-022-01097-9, 2023. a
Timmermann, R. and Hellmer, H. H.: Southern Ocean warming and increased ice shelf basal melting in the twenty-first and twenty-second centuries based on coupled ice-ocean finite-element modelling, Ocean Dynam., 63, 1011–1026, https://doi.org/10.1007/s10236-013-0642-0, 2013. a
van Wessem, J. M., van de Berg, W. J., Noël, B. P. Y., van Meijgaard, E., Amory, C., Birnbaum, G., Jakobs, C. L., Krüger, K., Lenaerts, J. T. M., Lhermitte, S., Ligtenberg, S. R. M., Medley, B., Reijmer, C. H., van Tricht, K., Trusel, L. D., van Ulft, L. H., Wouters, B., Wuite, J., and van den Broeke, M. R.: Modelling the climate and surface mass balance of polar ice sheets using RACMO2 – Part 2: Antarctica (1979–2016), The Cryosphere, 12, 1479–1498, https://doi.org/10.5194/tc-12-1479-2018, 2018. a, b
Weertman, J.: Stability of the Junction of an Ice Sheet and an Ice Shelf, J. Glaciol., 13, 3–11, https://doi.org/10.3189/s0022143000023327, 1974. a
Zhao, K. X., Stewart, A. L., and McWilliams, J. C.: Sill-Influenced Exchange Flows in Ice Shelf Cavities, J. Phys. Oceanogr., 49, 163–191, https://doi.org/10.1175/JPO-D-18-0076.1, 2019. a
Short summary
The West Antarctic Ice Sheet is losing ice at an accelerating pace. This is largely due to the presence of warm ocean water around the periphery of the Antarctic continent, which melts the ice. It is generally assumed that the strength of this process is controlled by the temperature of the ocean. However, in this study we show that an equally important role is played by the changing geometry of the ice sheet, which affects the strength of the ocean currents and thereby the melt rates.
The West Antarctic Ice Sheet is losing ice at an accelerating pace. This is largely due to the...
