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,...
Published in: | Elementa: Science of the Anthropocene |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
BioOne
2017
|
Subjects: | |
Online Access: | https://doi.org/10.1525/elementa.226 https://doaj.org/article/d8338ec62b004c289af0c368fa6158c2 |
id |
ftdoajarticles:oai:doaj.org/article:d8338ec62b004c289af0c368fa6158c2 |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:d8338ec62b004c289af0c368fa6158c2 2023-05-15T13:24:16+02:00 Sea ice drift in the Southern Ocean: Regional patterns, variability, and trends Ron Kwok Shirley S. Pang Sahra Kacimi 2017-06-01T00:00:00Z https://doi.org/10.1525/elementa.226 https://doaj.org/article/d8338ec62b004c289af0c368fa6158c2 EN eng BioOne https://www.elementascience.org/articles/226 https://doaj.org/toc/2325-1026 2325-1026 doi:10.1525/elementa.226 https://doaj.org/article/d8338ec62b004c289af0c368fa6158c2 Elementa: Science of the Anthropocene, Vol 5 (2017) Southern Ocean sea ice drift export sea ice edge Environmental sciences GE1-350 article 2017 ftdoajarticles https://doi.org/10.1525/elementa.226 2022-12-31T06:47:19Z 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. Copyright: © 2017 California Institute of Technology. U.S. Government sponsorship acknowledged. Article in Journal/Newspaper Amundsen Sea Antarc* Antarctic Arctic Riiser-Larsen Sea Ross Sea Sea ice Southern Ocean Directory of Open Access Journals: DOAJ Articles Amundsen Sea Antarctic Arctic Riiser-Larsen ENVELOPE(50.667,50.667,-66.783,-66.783) Riiser-Larsen Sea ENVELOPE(24.000,24.000,-68.000,-68.000) Ross Sea Southern Ocean The Antarctic Weddell Elementa: Science of the Anthropocene 5 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Southern Ocean sea ice drift export sea ice edge Environmental sciences GE1-350 |
spellingShingle |
Southern Ocean sea ice drift export sea ice edge Environmental sciences GE1-350 Ron Kwok Shirley S. Pang Sahra Kacimi Sea ice drift in the Southern Ocean: Regional patterns, variability, and trends |
topic_facet |
Southern Ocean sea ice drift export sea ice edge Environmental sciences GE1-350 |
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. Copyright: © 2017 California Institute of Technology. U.S. Government sponsorship acknowledged. |
format |
Article in Journal/Newspaper |
author |
Ron Kwok Shirley S. Pang Sahra Kacimi |
author_facet |
Ron Kwok Shirley S. Pang Sahra Kacimi |
author_sort |
Ron Kwok |
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 |
BioOne |
publishDate |
2017 |
url |
https://doi.org/10.1525/elementa.226 https://doaj.org/article/d8338ec62b004c289af0c368fa6158c2 |
long_lat |
ENVELOPE(50.667,50.667,-66.783,-66.783) ENVELOPE(24.000,24.000,-68.000,-68.000) |
geographic |
Amundsen Sea Antarctic Arctic Riiser-Larsen Riiser-Larsen Sea Ross Sea Southern Ocean The Antarctic Weddell |
geographic_facet |
Amundsen Sea Antarctic Arctic Riiser-Larsen Riiser-Larsen Sea Ross Sea Southern Ocean The Antarctic Weddell |
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, Vol 5 (2017) |
op_relation |
https://www.elementascience.org/articles/226 https://doaj.org/toc/2325-1026 2325-1026 doi:10.1525/elementa.226 https://doaj.org/article/d8338ec62b004c289af0c368fa6158c2 |
op_doi |
https://doi.org/10.1525/elementa.226 |
container_title |
Elementa: Science of the Anthropocene |
container_volume |
5 |
_version_ |
1766378430685773824 |