Sea ice drift in the Southern Ocean: Regional patterns, variability, and trends
Understanding long-term changes in large-scale sea ice drift in the Southern Ocean is of considerable interest given its contribution to ice extent, to ice production in open waters, with associated dense water formation and heat flux to the atmosphere, and thus to the climate system. In this paper,...
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crunicaliforniap:10.1525/elementa.226 2024-05-19T07:28:22+00:00 Sea ice drift in the Southern Ocean: Regional patterns, variability, and trends Kwok, Ron Pang, Shirley S. Kacimi, Sahra Deming, Jody W. Carmack, Eddy C. 2017 http://dx.doi.org/10.1525/elementa.226 http://online.ucpress.edu/elementa/article-pdf/doi/10.1525/elementa.226/473095/226-3251-1-pb.pdf en eng University of California Press http://creativecommons.org/licenses/by/4.0/ Elementa: Science of the Anthropocene volume 5 ISSN 2325-1026 journal-article 2017 crunicaliforniap https://doi.org/10.1525/elementa.226 2024-05-02T10:03:49Z Understanding long-term changes in large-scale sea ice drift in the Southern Ocean is of considerable interest given its contribution to ice extent, to ice production in open waters, with associated dense water formation and heat flux to the atmosphere, and thus to the climate system. In this paper, we examine the trends and variability of this ice drift in a 34-year record (1982–2015) derived from satellite observations. Uncertainties in drift (~3 to 4 km day–1) were assessed with higher resolution observations. In a linear model, drift speeds were ~1.4% of the geostrophic wind from reanalyzed sea-level pressure, nearly 50% higher than that of the Arctic. This result suggests an ice cover in the Southern Ocean that is thinner, weaker, and less compact. Geostrophic winds explained all but ~40% of the variance in ice drift. Three spatially distinct drift patterns were shown to be controlled by the location and depth of atmospheric lows centered over the Amundsen, Riiser-Larsen, and Davis seas. Positively correlated changes in sea-level pressures at the three centers (up to 0.64) suggest correlated changes in the wind-driven drift patterns. Seasonal trends in ice edge are linked to trends in meridional winds and also to on-ice/off-ice trends in zonal winds, due to zonal asymmetry of the Antarctic ice cover. Sea ice area export at flux gates that parallel the 1000-m isobath were extended to cover the 34-year record. Interannual variability in ice export in the Ross and Weddell seas linked to the depth and location of the Amundsen Sea and Riiser-Larsen Sea lows to their east. Compared to shorter records, where there was a significant positive trend in Ross Sea ice area flux, the longer 34-year trends of outflow from both seas are now statistically insignificant. Article in Journal/Newspaper Amundsen Sea Antarc* Antarctic Arctic Riiser-Larsen Sea Ross Sea Sea ice Southern Ocean University of California Press Elementa: Science of the Anthropocene 5 |
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Open Polar |
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University of California Press |
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crunicaliforniap |
language |
English |
description |
Understanding long-term changes in large-scale sea ice drift in the Southern Ocean is of considerable interest given its contribution to ice extent, to ice production in open waters, with associated dense water formation and heat flux to the atmosphere, and thus to the climate system. In this paper, we examine the trends and variability of this ice drift in a 34-year record (1982–2015) derived from satellite observations. Uncertainties in drift (~3 to 4 km day–1) were assessed with higher resolution observations. In a linear model, drift speeds were ~1.4% of the geostrophic wind from reanalyzed sea-level pressure, nearly 50% higher than that of the Arctic. This result suggests an ice cover in the Southern Ocean that is thinner, weaker, and less compact. Geostrophic winds explained all but ~40% of the variance in ice drift. Three spatially distinct drift patterns were shown to be controlled by the location and depth of atmospheric lows centered over the Amundsen, Riiser-Larsen, and Davis seas. Positively correlated changes in sea-level pressures at the three centers (up to 0.64) suggest correlated changes in the wind-driven drift patterns. Seasonal trends in ice edge are linked to trends in meridional winds and also to on-ice/off-ice trends in zonal winds, due to zonal asymmetry of the Antarctic ice cover. Sea ice area export at flux gates that parallel the 1000-m isobath were extended to cover the 34-year record. Interannual variability in ice export in the Ross and Weddell seas linked to the depth and location of the Amundsen Sea and Riiser-Larsen Sea lows to their east. Compared to shorter records, where there was a significant positive trend in Ross Sea ice area flux, the longer 34-year trends of outflow from both seas are now statistically insignificant. |
author2 |
Deming, Jody W. Carmack, Eddy C. |
format |
Article in Journal/Newspaper |
author |
Kwok, Ron Pang, Shirley S. Kacimi, Sahra |
spellingShingle |
Kwok, Ron Pang, Shirley S. Kacimi, Sahra Sea ice drift in the Southern Ocean: Regional patterns, variability, and trends |
author_facet |
Kwok, Ron Pang, Shirley S. Kacimi, Sahra |
author_sort |
Kwok, Ron |
title |
Sea ice drift in the Southern Ocean: Regional patterns, variability, and trends |
title_short |
Sea ice drift in the Southern Ocean: Regional patterns, variability, and trends |
title_full |
Sea ice drift in the Southern Ocean: Regional patterns, variability, and trends |
title_fullStr |
Sea ice drift in the Southern Ocean: Regional patterns, variability, and trends |
title_full_unstemmed |
Sea ice drift in the Southern Ocean: Regional patterns, variability, and trends |
title_sort |
sea ice drift in the southern ocean: regional patterns, variability, and trends |
publisher |
University of California Press |
publishDate |
2017 |
url |
http://dx.doi.org/10.1525/elementa.226 http://online.ucpress.edu/elementa/article-pdf/doi/10.1525/elementa.226/473095/226-3251-1-pb.pdf |
genre |
Amundsen Sea Antarc* Antarctic Arctic Riiser-Larsen Sea Ross Sea Sea ice Southern Ocean |
genre_facet |
Amundsen Sea Antarc* Antarctic Arctic Riiser-Larsen Sea Ross Sea Sea ice Southern Ocean |
op_source |
Elementa: Science of the Anthropocene volume 5 ISSN 2325-1026 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1525/elementa.226 |
container_title |
Elementa: Science of the Anthropocene |
container_volume |
5 |
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1799472600929271808 |