Interannual variability of summer surface mass balance and surface melting in the Amundsen sector, West Antarctica
Understanding the interannual variability of surface mass balance (SMB) and surface melting in Antarctica is key to quantify the signal-to-noise ratio in climate trends, identify opportunities for multi-year climate predictions and assess the ability of climate models to respond to climate variabili...
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ftdoajarticles:oai:doaj.org/article:6c1e7fbdf89043e680fc31aa0a60e466 2023-05-15T13:23:49+02:00 Interannual variability of summer surface mass balance and surface melting in the Amundsen sector, West Antarctica M. Donat-Magnin N. C. Jourdain H. Gallée C. Amory C. Kittel X. Fettweis J. D. Wille V. Favier A. Drira C. Agosta 2020-01-01T00:00:00Z https://doi.org/10.5194/tc-14-229-2020 https://doaj.org/article/6c1e7fbdf89043e680fc31aa0a60e466 EN eng Copernicus Publications https://www.the-cryosphere.net/14/229/2020/tc-14-229-2020.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-14-229-2020 1994-0416 1994-0424 https://doaj.org/article/6c1e7fbdf89043e680fc31aa0a60e466 The Cryosphere, Vol 14, Pp 229-249 (2020) Environmental sciences GE1-350 Geology QE1-996.5 article 2020 ftdoajarticles https://doi.org/10.5194/tc-14-229-2020 2022-12-31T11:56:32Z Understanding the interannual variability of surface mass balance (SMB) and surface melting in Antarctica is key to quantify the signal-to-noise ratio in climate trends, identify opportunities for multi-year climate predictions and assess the ability of climate models to respond to climate variability. Here we simulate summer SMB and surface melting from 1979 to 2017 using the Regional Atmosphere Model (MAR) at 10 km resolution over the drainage basins of the Amundsen Sea glaciers in West Antarctica. Our simulations reproduce the mean present-day climate in terms of near-surface temperature (mean overestimation of 0.10 ∘ C), near-surface wind speed (mean underestimation of 0.42 m s −1 ), and SMB (relative bias <20 % over Thwaites glacier). The simulated interannual variability of SMB and melting is also close to observation-based estimates. For all the Amundsen glacial drainage basins, the interannual variability of summer SMB and surface melting is driven by two distinct mechanisms: high summer SMB tends to occur when the Amundsen Sea Low (ASL) is shifted southward and westward, while high summer melt rates tend to occur when ASL is shallower (i.e. anticyclonic anomaly). Both mechanisms create a northerly flow anomaly that increases moisture convergence and cloud cover over the Amundsen Sea and therefore favors snowfall and downward longwave radiation over the ice sheet. The part of interannual summer SMB variance explained by the ASL longitudinal migrations increases westward and reaches 40 % for Getz. Interannual variation in the ASL relative central pressure is the largest driver of melt rate variability, with 11 % to 21 % of explained variance (increasing westward). While high summer SMB and melt rates are both favored by positive phases of El Niño–Southern Oscillation (ENSO), the Southern Oscillation Index (SOI) only explains 5 % to 16 % of SMB or melt rate interannual variance in our simulations, with moderate statistical significance. However, the part explained by SOI in the previous austral winter ... Article in Journal/Newspaper Amundsen Sea Antarc* Antarctica Ice Sheet The Cryosphere Thwaites Glacier West Antarctica Directory of Open Access Journals: DOAJ Articles Austral West Antarctica Amundsen Sea Soi ENVELOPE(30.704,30.704,66.481,66.481) Thwaites Glacier ENVELOPE(-106.750,-106.750,-75.500,-75.500) Getz ENVELOPE(-145.217,-145.217,-76.550,-76.550) The Cryosphere 14 1 229 249 |
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 M. Donat-Magnin N. C. Jourdain H. Gallée C. Amory C. Kittel X. Fettweis J. D. Wille V. Favier A. Drira C. Agosta Interannual variability of summer surface mass balance and surface melting in the Amundsen sector, West Antarctica |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Understanding the interannual variability of surface mass balance (SMB) and surface melting in Antarctica is key to quantify the signal-to-noise ratio in climate trends, identify opportunities for multi-year climate predictions and assess the ability of climate models to respond to climate variability. Here we simulate summer SMB and surface melting from 1979 to 2017 using the Regional Atmosphere Model (MAR) at 10 km resolution over the drainage basins of the Amundsen Sea glaciers in West Antarctica. Our simulations reproduce the mean present-day climate in terms of near-surface temperature (mean overestimation of 0.10 ∘ C), near-surface wind speed (mean underestimation of 0.42 m s −1 ), and SMB (relative bias <20 % over Thwaites glacier). The simulated interannual variability of SMB and melting is also close to observation-based estimates. For all the Amundsen glacial drainage basins, the interannual variability of summer SMB and surface melting is driven by two distinct mechanisms: high summer SMB tends to occur when the Amundsen Sea Low (ASL) is shifted southward and westward, while high summer melt rates tend to occur when ASL is shallower (i.e. anticyclonic anomaly). Both mechanisms create a northerly flow anomaly that increases moisture convergence and cloud cover over the Amundsen Sea and therefore favors snowfall and downward longwave radiation over the ice sheet. The part of interannual summer SMB variance explained by the ASL longitudinal migrations increases westward and reaches 40 % for Getz. Interannual variation in the ASL relative central pressure is the largest driver of melt rate variability, with 11 % to 21 % of explained variance (increasing westward). While high summer SMB and melt rates are both favored by positive phases of El Niño–Southern Oscillation (ENSO), the Southern Oscillation Index (SOI) only explains 5 % to 16 % of SMB or melt rate interannual variance in our simulations, with moderate statistical significance. However, the part explained by SOI in the previous austral winter ... |
format |
Article in Journal/Newspaper |
author |
M. Donat-Magnin N. C. Jourdain H. Gallée C. Amory C. Kittel X. Fettweis J. D. Wille V. Favier A. Drira C. Agosta |
author_facet |
M. Donat-Magnin N. C. Jourdain H. Gallée C. Amory C. Kittel X. Fettweis J. D. Wille V. Favier A. Drira C. Agosta |
author_sort |
M. Donat-Magnin |
title |
Interannual variability of summer surface mass balance and surface melting in the Amundsen sector, West Antarctica |
title_short |
Interannual variability of summer surface mass balance and surface melting in the Amundsen sector, West Antarctica |
title_full |
Interannual variability of summer surface mass balance and surface melting in the Amundsen sector, West Antarctica |
title_fullStr |
Interannual variability of summer surface mass balance and surface melting in the Amundsen sector, West Antarctica |
title_full_unstemmed |
Interannual variability of summer surface mass balance and surface melting in the Amundsen sector, West Antarctica |
title_sort |
interannual variability of summer surface mass balance and surface melting in the amundsen sector, west antarctica |
publisher |
Copernicus Publications |
publishDate |
2020 |
url |
https://doi.org/10.5194/tc-14-229-2020 https://doaj.org/article/6c1e7fbdf89043e680fc31aa0a60e466 |
long_lat |
ENVELOPE(30.704,30.704,66.481,66.481) ENVELOPE(-106.750,-106.750,-75.500,-75.500) ENVELOPE(-145.217,-145.217,-76.550,-76.550) |
geographic |
Austral West Antarctica Amundsen Sea Soi Thwaites Glacier Getz |
geographic_facet |
Austral West Antarctica Amundsen Sea Soi Thwaites Glacier Getz |
genre |
Amundsen Sea Antarc* Antarctica Ice Sheet The Cryosphere Thwaites Glacier West Antarctica |
genre_facet |
Amundsen Sea Antarc* Antarctica Ice Sheet The Cryosphere Thwaites Glacier West Antarctica |
op_source |
The Cryosphere, Vol 14, Pp 229-249 (2020) |
op_relation |
https://www.the-cryosphere.net/14/229/2020/tc-14-229-2020.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-14-229-2020 1994-0416 1994-0424 https://doaj.org/article/6c1e7fbdf89043e680fc31aa0a60e466 |
op_doi |
https://doi.org/10.5194/tc-14-229-2020 |
container_title |
The Cryosphere |
container_volume |
14 |
container_issue |
1 |
container_start_page |
229 |
op_container_end_page |
249 |
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1766375550676369408 |