The role of history and strength of the oceanic forcing in sea level projections from Antarctica with the Parallel Ice Sheet Model
Mass loss from the Antarctic Ice Sheet constitutes the largest uncertainty in projections of future sea level rise. Ocean-driven melting underneath the floating ice shelves and subsequent acceleration of the inland ice streams are the major reasons for currently observed mass loss from Antarctica an...
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Copernicus Publications
2020
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00053203 2023-05-15T13:54:46+02:00 The role of history and strength of the oceanic forcing in sea level projections from Antarctica with the Parallel Ice Sheet Model Reese, Ronja Levermann, Anders Albrecht, Torsten Seroussi, Hélène Winkelmann, Ricarda 2020-09 electronic https://doi.org/10.5194/tc-14-3097-2020 https://noa.gwlb.de/receive/cop_mods_00053203 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00052856/tc-14-3097-2020.pdf https://tc.copernicus.org/articles/14/3097/2020/tc-14-3097-2020.pdf eng eng Copernicus Publications The Cryosphere -- ˜Theœ Cryosphere -- http://www.bibliothek.uni-regensburg.de/ezeit/?2393169 -- http://www.the-cryosphere.net/ -- 1994-0424 https://doi.org/10.5194/tc-14-3097-2020 https://noa.gwlb.de/receive/cop_mods_00053203 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00052856/tc-14-3097-2020.pdf https://tc.copernicus.org/articles/14/3097/2020/tc-14-3097-2020.pdf https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess CC-BY article Verlagsveröffentlichung article Text doc-type:article 2020 ftnonlinearchiv https://doi.org/10.5194/tc-14-3097-2020 2022-02-08T22:35:36Z Mass loss from the Antarctic Ice Sheet constitutes the largest uncertainty in projections of future sea level rise. Ocean-driven melting underneath the floating ice shelves and subsequent acceleration of the inland ice streams are the major reasons for currently observed mass loss from Antarctica and are expected to become more important in the future. Here we show that for projections of future mass loss from the Antarctic Ice Sheet, it is essential (1) to better constrain the sensitivity of sub-shelf melt rates to ocean warming and (2) to include the historic trajectory of the ice sheet. In particular, we find that while the ice sheet response in simulations using the Parallel Ice Sheet Model is comparable to the median response of models in three Antarctic Ice Sheet Intercomparison projects – initMIP, LARMIP-2 and ISMIP6 – conducted with a range of ice sheet models, the projected 21st century sea level contribution differs significantly depending on these two factors. For the highest emission scenario RCP8.5, this leads to projected ice loss ranging from 1.4 to 4.0 cm of sea level equivalent in simulations in which ISMIP6 ocean forcing drives the PICO ocean box model where parameter tuning leads to a comparably low sub-shelf melt sensitivity and in which no surface forcing is applied. This is opposed to a likely range of 9.1 to 35.8 cm using the exact same initial setup, but emulated from the LARMIP-2 experiments with a higher melt sensitivity, even though both projects use forcing from climate models and melt rates are calibrated with previous oceanographic studies. Furthermore, using two initial states, one with a previous historic simulation from 1850 to 2014 and one starting from a steady state, we show that while differences between the ice sheet configurations in 2015 seem marginal at first sight, the historic simulation increases the susceptibility of the ice sheet to ocean warming, thereby increasing mass loss from 2015 to 2100 by 5 % to 50 %. Hindcasting past ice sheet changes with numerical models would thus provide valuable tools to better constrain projections. Our results emphasize that the uncertainty that arises from the forcing is of the same order of magnitude as the ice dynamic response for future sea level projections. Article in Journal/Newspaper Antarc* Antarctic Antarctica Ice Sheet Ice Shelves The Cryosphere Niedersächsisches Online-Archiv NOA Antarctic The Antarctic The Cryosphere 14 9 3097 3110 |
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English |
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article Verlagsveröffentlichung |
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article Verlagsveröffentlichung Reese, Ronja Levermann, Anders Albrecht, Torsten Seroussi, Hélène Winkelmann, Ricarda The role of history and strength of the oceanic forcing in sea level projections from Antarctica with the Parallel Ice Sheet Model |
topic_facet |
article Verlagsveröffentlichung |
description |
Mass loss from the Antarctic Ice Sheet constitutes the largest uncertainty in projections of future sea level rise. Ocean-driven melting underneath the floating ice shelves and subsequent acceleration of the inland ice streams are the major reasons for currently observed mass loss from Antarctica and are expected to become more important in the future. Here we show that for projections of future mass loss from the Antarctic Ice Sheet, it is essential (1) to better constrain the sensitivity of sub-shelf melt rates to ocean warming and (2) to include the historic trajectory of the ice sheet. In particular, we find that while the ice sheet response in simulations using the Parallel Ice Sheet Model is comparable to the median response of models in three Antarctic Ice Sheet Intercomparison projects – initMIP, LARMIP-2 and ISMIP6 – conducted with a range of ice sheet models, the projected 21st century sea level contribution differs significantly depending on these two factors. For the highest emission scenario RCP8.5, this leads to projected ice loss ranging from 1.4 to 4.0 cm of sea level equivalent in simulations in which ISMIP6 ocean forcing drives the PICO ocean box model where parameter tuning leads to a comparably low sub-shelf melt sensitivity and in which no surface forcing is applied. This is opposed to a likely range of 9.1 to 35.8 cm using the exact same initial setup, but emulated from the LARMIP-2 experiments with a higher melt sensitivity, even though both projects use forcing from climate models and melt rates are calibrated with previous oceanographic studies. Furthermore, using two initial states, one with a previous historic simulation from 1850 to 2014 and one starting from a steady state, we show that while differences between the ice sheet configurations in 2015 seem marginal at first sight, the historic simulation increases the susceptibility of the ice sheet to ocean warming, thereby increasing mass loss from 2015 to 2100 by 5 % to 50 %. Hindcasting past ice sheet changes with numerical models would thus provide valuable tools to better constrain projections. Our results emphasize that the uncertainty that arises from the forcing is of the same order of magnitude as the ice dynamic response for future sea level projections. |
format |
Article in Journal/Newspaper |
author |
Reese, Ronja Levermann, Anders Albrecht, Torsten Seroussi, Hélène Winkelmann, Ricarda |
author_facet |
Reese, Ronja Levermann, Anders Albrecht, Torsten Seroussi, Hélène Winkelmann, Ricarda |
author_sort |
Reese, Ronja |
title |
The role of history and strength of the oceanic forcing in sea level projections from Antarctica with the Parallel Ice Sheet Model |
title_short |
The role of history and strength of the oceanic forcing in sea level projections from Antarctica with the Parallel Ice Sheet Model |
title_full |
The role of history and strength of the oceanic forcing in sea level projections from Antarctica with the Parallel Ice Sheet Model |
title_fullStr |
The role of history and strength of the oceanic forcing in sea level projections from Antarctica with the Parallel Ice Sheet Model |
title_full_unstemmed |
The role of history and strength of the oceanic forcing in sea level projections from Antarctica with the Parallel Ice Sheet Model |
title_sort |
role of history and strength of the oceanic forcing in sea level projections from antarctica with the parallel ice sheet model |
publisher |
Copernicus Publications |
publishDate |
2020 |
url |
https://doi.org/10.5194/tc-14-3097-2020 https://noa.gwlb.de/receive/cop_mods_00053203 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00052856/tc-14-3097-2020.pdf https://tc.copernicus.org/articles/14/3097/2020/tc-14-3097-2020.pdf |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Antarctica Ice Sheet Ice Shelves The Cryosphere |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Ice Shelves The Cryosphere |
op_relation |
The Cryosphere -- ˜Theœ Cryosphere -- http://www.bibliothek.uni-regensburg.de/ezeit/?2393169 -- http://www.the-cryosphere.net/ -- 1994-0424 https://doi.org/10.5194/tc-14-3097-2020 https://noa.gwlb.de/receive/cop_mods_00053203 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00052856/tc-14-3097-2020.pdf https://tc.copernicus.org/articles/14/3097/2020/tc-14-3097-2020.pdf |
op_rights |
https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/tc-14-3097-2020 |
container_title |
The Cryosphere |
container_volume |
14 |
container_issue |
9 |
container_start_page |
3097 |
op_container_end_page |
3110 |
_version_ |
1766260874541006848 |