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...
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ftdoajarticles:oai:doaj.org/article:8988152ffc2541a2a1b07cff5bdadac7 2023-05-15T13:30:42+02:00 Downscaled surface mass balance in Antarctica: impacts of subsurface processes and large-scale atmospheric circulation N. Hansen P. L. Langen F. Boberg R. Forsberg S. B. Simonsen P. Thejll B. Vandecrux R. Mottram 2021-09-01T00:00:00Z https://doi.org/10.5194/tc-15-4315-2021 https://doaj.org/article/8988152ffc2541a2a1b07cff5bdadac7 EN eng Copernicus Publications https://tc.copernicus.org/articles/15/4315/2021/tc-15-4315-2021.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-15-4315-2021 1994-0416 1994-0424 https://doaj.org/article/8988152ffc2541a2a1b07cff5bdadac7 The Cryosphere, Vol 15, Pp 4315-4333 (2021) Environmental sciences GE1-350 Geology QE1-996.5 article 2021 ftdoajarticles https://doi.org/10.5194/tc-15-4315-2021 2022-12-31T05:58:29Z 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 ... Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Antarctica East Antarctica Ice Sheet Ice Shelves The Cryosphere Directory of Open Access Journals: DOAJ Articles Antarctic The Antarctic Antarctic Peninsula East Antarctica The Cryosphere 15 9 4315 4333 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 N. Hansen P. L. Langen F. Boberg R. Forsberg S. B. Simonsen P. Thejll B. Vandecrux R. Mottram Downscaled surface mass balance in Antarctica: impacts of subsurface processes and large-scale atmospheric circulation |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
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 ... |
format |
Article in Journal/Newspaper |
author |
N. Hansen P. L. Langen F. Boberg R. Forsberg S. B. Simonsen P. Thejll B. Vandecrux R. Mottram |
author_facet |
N. Hansen P. L. Langen F. Boberg R. Forsberg S. B. Simonsen P. Thejll B. Vandecrux R. Mottram |
author_sort |
N. Hansen |
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://doaj.org/article/8988152ffc2541a2a1b07cff5bdadac7 |
geographic |
Antarctic The Antarctic Antarctic Peninsula East Antarctica |
geographic_facet |
Antarctic The Antarctic Antarctic Peninsula East Antarctica |
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_source |
The Cryosphere, Vol 15, Pp 4315-4333 (2021) |
op_relation |
https://tc.copernicus.org/articles/15/4315/2021/tc-15-4315-2021.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-15-4315-2021 1994-0416 1994-0424 https://doaj.org/article/8988152ffc2541a2a1b07cff5bdadac7 |
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 |
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1766011465288908800 |