Anthropogenic and internal drivers of wind changes over the Amundsen Sea, West Antarctica, during the 20th and 21st centuries
Ocean-driven ice loss from the West Antarctic Ice Sheet is a significant contributor to sea-level rise. Recent ocean variability in the Amundsen Sea is controlled by near-surface winds. We combine palaeoclimate reconstructions and climate model simulations to understand past and future influences on...
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ftcopernicus:oai:publications.copernicus.org:tc104635 2023-05-15T13:23:30+02:00 Anthropogenic and internal drivers of wind changes over the Amundsen Sea, West Antarctica, during the 20th and 21st centuries Holland, Paul R. O'Connor, Gemma K. Bracegirdle, Thomas J. Dutrieux, Pierre Naughten, Kaitlin A. Steig, Eric J. Schneider, David P. Jenkins, Adrian Smith, James A. 2022-12-22 application/pdf https://doi.org/10.5194/tc-16-5085-2022 https://tc.copernicus.org/articles/16/5085/2022/ eng eng doi:10.5194/tc-16-5085-2022 https://tc.copernicus.org/articles/16/5085/2022/ eISSN: 1994-0424 Text 2022 ftcopernicus https://doi.org/10.5194/tc-16-5085-2022 2022-12-26T17:22:42Z Ocean-driven ice loss from the West Antarctic Ice Sheet is a significant contributor to sea-level rise. Recent ocean variability in the Amundsen Sea is controlled by near-surface winds. We combine palaeoclimate reconstructions and climate model simulations to understand past and future influences on Amundsen Sea winds from anthropogenic forcing and internal climate variability. The reconstructions show strong historical wind trends. External forcing from greenhouse gases and stratospheric ozone depletion drove zonally uniform westerly wind trends centred over the deep Southern Ocean. Internally generated trends resemble a South Pacific Rossby wave train and were highly influential over the Amundsen Sea continental shelf. There was strong interannual and interdecadal variability over the Amundsen Sea, with periods of anticyclonic wind anomalies in the 1940s and 1990s, when rapid ice-sheet loss was initiated. Similar anticyclonic anomalies probably occurred prior to the 20th century but without causing the present ice loss. This suggests that ice loss may have been triggered naturally in the 1940s but failed to recover subsequently due to the increasing importance of anthropogenic forcing from greenhouse gases (since the 1960s) and ozone depletion (since the 1980s). Future projections also feature strong wind trends. Emissions mitigation influences wind trends over the deep Southern Ocean but has less influence on winds over the Amundsen Sea shelf, where internal variability creates a large and irreducible uncertainty. This suggests that strong emissions mitigation is needed to minimise ice loss this century but that the uncontrollable future influence of internal climate variability could be equally important. Text Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet Southern Ocean West Antarctica Copernicus Publications: E-Journals Amundsen Sea Antarctic Pacific Southern Ocean West Antarctic Ice Sheet West Antarctica The Cryosphere 16 12 5085 5105 |
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Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
Ocean-driven ice loss from the West Antarctic Ice Sheet is a significant contributor to sea-level rise. Recent ocean variability in the Amundsen Sea is controlled by near-surface winds. We combine palaeoclimate reconstructions and climate model simulations to understand past and future influences on Amundsen Sea winds from anthropogenic forcing and internal climate variability. The reconstructions show strong historical wind trends. External forcing from greenhouse gases and stratospheric ozone depletion drove zonally uniform westerly wind trends centred over the deep Southern Ocean. Internally generated trends resemble a South Pacific Rossby wave train and were highly influential over the Amundsen Sea continental shelf. There was strong interannual and interdecadal variability over the Amundsen Sea, with periods of anticyclonic wind anomalies in the 1940s and 1990s, when rapid ice-sheet loss was initiated. Similar anticyclonic anomalies probably occurred prior to the 20th century but without causing the present ice loss. This suggests that ice loss may have been triggered naturally in the 1940s but failed to recover subsequently due to the increasing importance of anthropogenic forcing from greenhouse gases (since the 1960s) and ozone depletion (since the 1980s). Future projections also feature strong wind trends. Emissions mitigation influences wind trends over the deep Southern Ocean but has less influence on winds over the Amundsen Sea shelf, where internal variability creates a large and irreducible uncertainty. This suggests that strong emissions mitigation is needed to minimise ice loss this century but that the uncontrollable future influence of internal climate variability could be equally important. |
format |
Text |
author |
Holland, Paul R. O'Connor, Gemma K. Bracegirdle, Thomas J. Dutrieux, Pierre Naughten, Kaitlin A. Steig, Eric J. Schneider, David P. Jenkins, Adrian Smith, James A. |
spellingShingle |
Holland, Paul R. O'Connor, Gemma K. Bracegirdle, Thomas J. Dutrieux, Pierre Naughten, Kaitlin A. Steig, Eric J. Schneider, David P. Jenkins, Adrian Smith, James A. Anthropogenic and internal drivers of wind changes over the Amundsen Sea, West Antarctica, during the 20th and 21st centuries |
author_facet |
Holland, Paul R. O'Connor, Gemma K. Bracegirdle, Thomas J. Dutrieux, Pierre Naughten, Kaitlin A. Steig, Eric J. Schneider, David P. Jenkins, Adrian Smith, James A. |
author_sort |
Holland, Paul R. |
title |
Anthropogenic and internal drivers of wind changes over the Amundsen Sea, West Antarctica, during the 20th and 21st centuries |
title_short |
Anthropogenic and internal drivers of wind changes over the Amundsen Sea, West Antarctica, during the 20th and 21st centuries |
title_full |
Anthropogenic and internal drivers of wind changes over the Amundsen Sea, West Antarctica, during the 20th and 21st centuries |
title_fullStr |
Anthropogenic and internal drivers of wind changes over the Amundsen Sea, West Antarctica, during the 20th and 21st centuries |
title_full_unstemmed |
Anthropogenic and internal drivers of wind changes over the Amundsen Sea, West Antarctica, during the 20th and 21st centuries |
title_sort |
anthropogenic and internal drivers of wind changes over the amundsen sea, west antarctica, during the 20th and 21st centuries |
publishDate |
2022 |
url |
https://doi.org/10.5194/tc-16-5085-2022 https://tc.copernicus.org/articles/16/5085/2022/ |
geographic |
Amundsen Sea Antarctic Pacific Southern Ocean West Antarctic Ice Sheet West Antarctica |
geographic_facet |
Amundsen Sea Antarctic Pacific Southern Ocean West Antarctic Ice Sheet West Antarctica |
genre |
Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet Southern Ocean West Antarctica |
genre_facet |
Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet Southern Ocean West Antarctica |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-16-5085-2022 https://tc.copernicus.org/articles/16/5085/2022/ |
op_doi |
https://doi.org/10.5194/tc-16-5085-2022 |
container_title |
The Cryosphere |
container_volume |
16 |
container_issue |
12 |
container_start_page |
5085 |
op_container_end_page |
5105 |
_version_ |
1766372776272199680 |