Downscaled surface mass balance in Antarctica: impacts of subsurface processes and large-scale atmospheric circulation
Antarctic surface mass balance (SMB) is largely determined by precipitation over the continent and subject to regional climate variability related to the Southern Annular Mode (SAM) and other climatic drivers at the large scale. Locally however, firn and snowpack processes are important in determini...
Published in: | The Cryosphere |
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Copernicus Publications
2021
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00058093 2023-05-15T13:37:33+02:00 Downscaled surface mass balance in Antarctica: impacts of subsurface processes and large-scale atmospheric circulation Hansen, Nicolaj Langen, Peter L. Boberg, Fredrik Forsberg, Rene Simonsen, Sebastian B. Thejll, Peter Vandecrux, Baptiste Mottram, Ruth 2021-09 electronic https://doi.org/10.5194/tc-15-4315-2021 https://noa.gwlb.de/receive/cop_mods_00058093 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00057743/tc-15-4315-2021.pdf https://tc.copernicus.org/articles/15/4315/2021/tc-15-4315-2021.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-15-4315-2021 https://noa.gwlb.de/receive/cop_mods_00058093 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00057743/tc-15-4315-2021.pdf https://tc.copernicus.org/articles/15/4315/2021/tc-15-4315-2021.pdf https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess CC-BY article Verlagsveröffentlichung article Text doc-type:article 2021 ftnonlinearchiv https://doi.org/10.5194/tc-15-4315-2021 2022-02-08T22:33:15Z Antarctic surface mass balance (SMB) is largely determined by precipitation over the continent and subject to regional climate variability related to the Southern Annular Mode (SAM) and other climatic drivers at the large scale. Locally however, firn and snowpack processes are important in determining SMB and the total mass balance of Antarctica and global sea level. Here, we examine factors that influence Antarctic SMB and attempt to reconcile the outcome with estimates for total mass balance determined from the GRACE satellites. This is done by having the regional climate model HIRHAM5 forcing two versions of an offline subsurface model, to estimate Antarctic ice sheet (AIS) SMB from 1980 to 2017. The Lagrangian subsurface model estimates Antarctic SMB of 2473.5±114.4 Gt yr−1, while the Eulerian subsurface model variant results in slightly higher modelled SMB of 2564.8±113.7 Gt yr−1. The majority of this difference in modelled SMB is due to melt and refreezing over ice shelves and demonstrates the importance of firn modelling in areas with substantial melt. Both the Eulerian and the Lagrangian SMB estimates are within uncertainty ranges of each other and within the range of other SMB studies. However, the Lagrangian version has better statistics when modelling the densities. Further, analysis of the relationship between SMB in individual drainage basins and the SAM is carried out using a bootstrapping approach. This shows a robust relationship between SAM and SMB in half of the basins (13 out of 27). In general, when SAM is positive there is a lower SMB over the plateau and a higher SMB on the westerly side of the Antarctic Peninsula, and vice versa when the SAM is negative. Finally, we compare the modelled SMB to GRACE data by subtracting the solid ice discharge, and we find that there is a good agreement in East Antarctica but large disagreements over the Antarctic Peninsula. There is a large difference between published estimates of discharge that make it challenging to use mass reconciliation in evaluating SMB models on the basin scale. Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Antarctica East Antarctica Ice Sheet Ice Shelves The Cryosphere Niedersächsisches Online-Archiv NOA Antarctic Antarctic Peninsula East Antarctica The Antarctic The Cryosphere 15 9 4315 4333 |
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Niedersächsisches Online-Archiv NOA |
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English |
topic |
article Verlagsveröffentlichung |
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article Verlagsveröffentlichung Hansen, Nicolaj Langen, Peter L. Boberg, Fredrik Forsberg, Rene Simonsen, Sebastian B. Thejll, Peter Vandecrux, Baptiste Mottram, Ruth Downscaled surface mass balance in Antarctica: impacts of subsurface processes and large-scale atmospheric circulation |
topic_facet |
article Verlagsveröffentlichung |
description |
Antarctic surface mass balance (SMB) is largely determined by precipitation over the continent and subject to regional climate variability related to the Southern Annular Mode (SAM) and other climatic drivers at the large scale. Locally however, firn and snowpack processes are important in determining SMB and the total mass balance of Antarctica and global sea level. Here, we examine factors that influence Antarctic SMB and attempt to reconcile the outcome with estimates for total mass balance determined from the GRACE satellites. This is done by having the regional climate model HIRHAM5 forcing two versions of an offline subsurface model, to estimate Antarctic ice sheet (AIS) SMB from 1980 to 2017. The Lagrangian subsurface model estimates Antarctic SMB of 2473.5±114.4 Gt yr−1, while the Eulerian subsurface model variant results in slightly higher modelled SMB of 2564.8±113.7 Gt yr−1. The majority of this difference in modelled SMB is due to melt and refreezing over ice shelves and demonstrates the importance of firn modelling in areas with substantial melt. Both the Eulerian and the Lagrangian SMB estimates are within uncertainty ranges of each other and within the range of other SMB studies. However, the Lagrangian version has better statistics when modelling the densities. Further, analysis of the relationship between SMB in individual drainage basins and the SAM is carried out using a bootstrapping approach. This shows a robust relationship between SAM and SMB in half of the basins (13 out of 27). In general, when SAM is positive there is a lower SMB over the plateau and a higher SMB on the westerly side of the Antarctic Peninsula, and vice versa when the SAM is negative. Finally, we compare the modelled SMB to GRACE data by subtracting the solid ice discharge, and we find that there is a good agreement in East Antarctica but large disagreements over the Antarctic Peninsula. There is a large difference between published estimates of discharge that make it challenging to use mass reconciliation in evaluating SMB models on the basin scale. |
format |
Article in Journal/Newspaper |
author |
Hansen, Nicolaj Langen, Peter L. Boberg, Fredrik Forsberg, Rene Simonsen, Sebastian B. Thejll, Peter Vandecrux, Baptiste Mottram, Ruth |
author_facet |
Hansen, Nicolaj Langen, Peter L. Boberg, Fredrik Forsberg, Rene Simonsen, Sebastian B. Thejll, Peter Vandecrux, Baptiste Mottram, Ruth |
author_sort |
Hansen, Nicolaj |
title |
Downscaled surface mass balance in Antarctica: impacts of subsurface processes and large-scale atmospheric circulation |
title_short |
Downscaled surface mass balance in Antarctica: impacts of subsurface processes and large-scale atmospheric circulation |
title_full |
Downscaled surface mass balance in Antarctica: impacts of subsurface processes and large-scale atmospheric circulation |
title_fullStr |
Downscaled surface mass balance in Antarctica: impacts of subsurface processes and large-scale atmospheric circulation |
title_full_unstemmed |
Downscaled surface mass balance in Antarctica: impacts of subsurface processes and large-scale atmospheric circulation |
title_sort |
downscaled surface mass balance in antarctica: impacts of subsurface processes and large-scale atmospheric circulation |
publisher |
Copernicus Publications |
publishDate |
2021 |
url |
https://doi.org/10.5194/tc-15-4315-2021 https://noa.gwlb.de/receive/cop_mods_00058093 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00057743/tc-15-4315-2021.pdf https://tc.copernicus.org/articles/15/4315/2021/tc-15-4315-2021.pdf |
geographic |
Antarctic Antarctic Peninsula East Antarctica The Antarctic |
geographic_facet |
Antarctic Antarctic Peninsula East Antarctica The Antarctic |
genre |
Antarc* Antarctic Antarctic Peninsula Antarctica East Antarctica Ice Sheet Ice Shelves The Cryosphere |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Antarctica East 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-15-4315-2021 https://noa.gwlb.de/receive/cop_mods_00058093 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00057743/tc-15-4315-2021.pdf https://tc.copernicus.org/articles/15/4315/2021/tc-15-4315-2021.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-15-4315-2021 |
container_title |
The Cryosphere |
container_volume |
15 |
container_issue |
9 |
container_start_page |
4315 |
op_container_end_page |
4333 |
_version_ |
1766094001705844736 |