Southern Ocean heat storage, reemergence, and winter sea ice decline induced by summertime winds
The observational record shows a substantial 40-yr upward trend in summertime westerly winds over the Southern Ocean, as characterized by the southern annular mode (SAM) index. Enhanced summertime westerly winds have been linked to cold summertime sea surface temperature (SST) anomalies. Previous st...
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ftunivtasmania:oai:eprints.utas.edu.au:36020 2023-05-15T18:16:33+02:00 Southern Ocean heat storage, reemergence, and winter sea ice decline induced by summertime winds Doddridge, EW Marshall, J Song, H Campin, J-M Kelley, M 2021 application/pdf https://eprints.utas.edu.au/36020/ https://eprints.utas.edu.au/36020/1/142582%20-%20Southern%20Ocean%20heat%20storage,%20reemergence,%20and%20winter%20sea%20ice%20decline%20induced.pdf en eng Amer Meteorological Soc https://eprints.utas.edu.au/36020/1/142582%20-%20Southern%20Ocean%20heat%20storage,%20reemergence,%20and%20winter%20sea%20ice%20decline%20induced.pdf Doddridge, EW orcid:0000-0002-6097-5729 , Marshall, J, Song, H, Campin, J-M and Kelley, M 2021 , 'Southern Ocean heat storage, reemergence, and winter sea ice decline induced by summertime winds' , Journal of Climate, vol. 34, no. 4 , 1403–1415 , doi:10.1175/JCLI-D-20-0322.1 <http://dx.doi.org/10.1175/JCLI-D-20-0322.1>. Southern Ocean sea ice mixing wind atmosphere-ocean interactions oceanic mixed layer sea surface temperature Article PeerReviewed 2021 ftunivtasmania https://doi.org/10.1175/JCLI-D-20-0322.1 2021-10-04T22:19:48Z The observational record shows a substantial 40-yr upward trend in summertime westerly winds over the Southern Ocean, as characterized by the southern annular mode (SAM) index. Enhanced summertime westerly winds have been linked to cold summertime sea surface temperature (SST) anomalies. Previous studies have suggested that Ekman transport or upwelling is responsible for this seasonal cooling. Here, another process is presented in which enhanced vertical mixing, driven by summertime wind anomalies, moves heat downward, cooling the sea surface and simultaneously warming the subsurface waters. The anomalously cold SSTs draw heat from the atmosphere into the ocean, leading to increased depth-integrated ocean heat content. The subsurface heat is returned to the surface mixed layer during the autumn and winter as the mixed layer deepens, leading to anomalously warm SSTs and potentially reducing sea ice cover. Observational analyses and numerical experiments support our proposed mechanism, showing that enhanced vertical mixing produces subsurface warming and cools the surface mixed layer. Nevertheless, the dominant driver of surface cooling remains uncertain; the relative importance of advective and mixing contributions to the surface cooling is model dependent. Modeling results suggest that sea ice volume is more sensitive to summertime winds than sea ice extent, implying that enhanced summertime westerly winds may lead to thinner sea ice in the following winter, if not lesser ice extent. Thus, strong summertime winds could precondition the sea ice cover for a rapid retreat in the following melt season. Article in Journal/Newspaper Sea ice Southern Ocean University of Tasmania: UTas ePrints Southern Ocean Journal of Climate 34 4 1403 1415 |
institution |
Open Polar |
collection |
University of Tasmania: UTas ePrints |
op_collection_id |
ftunivtasmania |
language |
English |
topic |
Southern Ocean sea ice mixing wind atmosphere-ocean interactions oceanic mixed layer sea surface temperature |
spellingShingle |
Southern Ocean sea ice mixing wind atmosphere-ocean interactions oceanic mixed layer sea surface temperature Doddridge, EW Marshall, J Song, H Campin, J-M Kelley, M Southern Ocean heat storage, reemergence, and winter sea ice decline induced by summertime winds |
topic_facet |
Southern Ocean sea ice mixing wind atmosphere-ocean interactions oceanic mixed layer sea surface temperature |
description |
The observational record shows a substantial 40-yr upward trend in summertime westerly winds over the Southern Ocean, as characterized by the southern annular mode (SAM) index. Enhanced summertime westerly winds have been linked to cold summertime sea surface temperature (SST) anomalies. Previous studies have suggested that Ekman transport or upwelling is responsible for this seasonal cooling. Here, another process is presented in which enhanced vertical mixing, driven by summertime wind anomalies, moves heat downward, cooling the sea surface and simultaneously warming the subsurface waters. The anomalously cold SSTs draw heat from the atmosphere into the ocean, leading to increased depth-integrated ocean heat content. The subsurface heat is returned to the surface mixed layer during the autumn and winter as the mixed layer deepens, leading to anomalously warm SSTs and potentially reducing sea ice cover. Observational analyses and numerical experiments support our proposed mechanism, showing that enhanced vertical mixing produces subsurface warming and cools the surface mixed layer. Nevertheless, the dominant driver of surface cooling remains uncertain; the relative importance of advective and mixing contributions to the surface cooling is model dependent. Modeling results suggest that sea ice volume is more sensitive to summertime winds than sea ice extent, implying that enhanced summertime westerly winds may lead to thinner sea ice in the following winter, if not lesser ice extent. Thus, strong summertime winds could precondition the sea ice cover for a rapid retreat in the following melt season. |
format |
Article in Journal/Newspaper |
author |
Doddridge, EW Marshall, J Song, H Campin, J-M Kelley, M |
author_facet |
Doddridge, EW Marshall, J Song, H Campin, J-M Kelley, M |
author_sort |
Doddridge, EW |
title |
Southern Ocean heat storage, reemergence, and winter sea ice decline induced by summertime winds |
title_short |
Southern Ocean heat storage, reemergence, and winter sea ice decline induced by summertime winds |
title_full |
Southern Ocean heat storage, reemergence, and winter sea ice decline induced by summertime winds |
title_fullStr |
Southern Ocean heat storage, reemergence, and winter sea ice decline induced by summertime winds |
title_full_unstemmed |
Southern Ocean heat storage, reemergence, and winter sea ice decline induced by summertime winds |
title_sort |
southern ocean heat storage, reemergence, and winter sea ice decline induced by summertime winds |
publisher |
Amer Meteorological Soc |
publishDate |
2021 |
url |
https://eprints.utas.edu.au/36020/ https://eprints.utas.edu.au/36020/1/142582%20-%20Southern%20Ocean%20heat%20storage,%20reemergence,%20and%20winter%20sea%20ice%20decline%20induced.pdf |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Sea ice Southern Ocean |
genre_facet |
Sea ice Southern Ocean |
op_relation |
https://eprints.utas.edu.au/36020/1/142582%20-%20Southern%20Ocean%20heat%20storage,%20reemergence,%20and%20winter%20sea%20ice%20decline%20induced.pdf Doddridge, EW orcid:0000-0002-6097-5729 , Marshall, J, Song, H, Campin, J-M and Kelley, M 2021 , 'Southern Ocean heat storage, reemergence, and winter sea ice decline induced by summertime winds' , Journal of Climate, vol. 34, no. 4 , 1403–1415 , doi:10.1175/JCLI-D-20-0322.1 <http://dx.doi.org/10.1175/JCLI-D-20-0322.1>. |
op_doi |
https://doi.org/10.1175/JCLI-D-20-0322.1 |
container_title |
Journal of Climate |
container_volume |
34 |
container_issue |
4 |
container_start_page |
1403 |
op_container_end_page |
1415 |
_version_ |
1766190231107665920 |