On the Generation of Weddell Sea Polynyas in a High-Resolution Earth System Model
<jats:title>Abstract</jats:title><jats:p>Larger Weddell Sea polynyas (WSPs), differentiated in this study from the smaller Maud Rise Polynyas (MRPs) that form to the east of the prime meridian in the proximity of the Maud Rise seamount, have last been observed in the 1970s. We inve...
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Online Access: | http://www.osti.gov/servlets/purl/1807832 https://www.osti.gov/biblio/1807832 https://doi.org/10.1175/jcli-d-20-0229.1 |
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ftosti:oai:osti.gov:1807832 2023-07-30T03:59:21+02:00 On the Generation of Weddell Sea Polynyas in a High-Resolution Earth System Model Kurtakoti, Prajvala Veneziani, Milena Stössel, Achim Weijer, Wilbert Maltrud, Mathew 2023-02-23 application/pdf http://www.osti.gov/servlets/purl/1807832 https://www.osti.gov/biblio/1807832 https://doi.org/10.1175/jcli-d-20-0229.1 unknown http://www.osti.gov/servlets/purl/1807832 https://www.osti.gov/biblio/1807832 https://doi.org/10.1175/jcli-d-20-0229.1 doi:10.1175/jcli-d-20-0229.1 2023 ftosti https://doi.org/10.1175/jcli-d-20-0229.1 2023-07-11T10:05:26Z <jats:title>Abstract</jats:title><jats:p>Larger Weddell Sea polynyas (WSPs), differentiated in this study from the smaller Maud Rise Polynyas (MRPs) that form to the east of the prime meridian in the proximity of the Maud Rise seamount, have last been observed in the 1970s. We investigate WSPs that grow realistically out of MRPs in a high-resolution preindustrial simulation with the Energy Exascale Earth System Model, version 0.1. The formation of MRPs requires high resolution to simulate the detailed flow around Maud Rise, whereas the realistic formation of WSPs requires a model to produce MRPs. Furthermore, WSPs tend to follow periods of a prolonged buildup of a heat reservoir at depth and weakly negative wind stress curl in association with the core of the Southern Hemisphere westerlies at an anomalously northern position. While this scenario also leads to drier conditions over the central Weddell Sea, which some literature claims to be a necessary condition for the formation of WSPs, our model results indicate that open-ocean polynyas do not occur during periods of weakly negative wind stress curl despite drier atmospheric conditions. Our study supports the hypothesis noted in earlier studies that a shift from a weakly negative to a strongly negative wind stress curl over the Weddell Sea is a prerequisite for WSPs to form, together with a large heat reservoir at depth. However, the ultimate trigger is a pronounced MRP, whose associated convection creates high surface salinity anomalies that propagate westward with the flow of the Weddell Gyre. If large enough, these anomalies trigger the formation of a WSP and a pulse of newly formed Antarctic Bottom Water.</jats:p> Other/Unknown Material Antarc* Antarctic Weddell Sea SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) Antarctic Weddell Sea Weddell Curl ENVELOPE(-63.071,-63.071,-70.797,-70.797) Maud Rise ENVELOPE(3.000,3.000,-66.000,-66.000) Journal of Climate 34 7 2491 2510 |
institution |
Open Polar |
collection |
SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) |
op_collection_id |
ftosti |
language |
unknown |
description |
<jats:title>Abstract</jats:title><jats:p>Larger Weddell Sea polynyas (WSPs), differentiated in this study from the smaller Maud Rise Polynyas (MRPs) that form to the east of the prime meridian in the proximity of the Maud Rise seamount, have last been observed in the 1970s. We investigate WSPs that grow realistically out of MRPs in a high-resolution preindustrial simulation with the Energy Exascale Earth System Model, version 0.1. The formation of MRPs requires high resolution to simulate the detailed flow around Maud Rise, whereas the realistic formation of WSPs requires a model to produce MRPs. Furthermore, WSPs tend to follow periods of a prolonged buildup of a heat reservoir at depth and weakly negative wind stress curl in association with the core of the Southern Hemisphere westerlies at an anomalously northern position. While this scenario also leads to drier conditions over the central Weddell Sea, which some literature claims to be a necessary condition for the formation of WSPs, our model results indicate that open-ocean polynyas do not occur during periods of weakly negative wind stress curl despite drier atmospheric conditions. Our study supports the hypothesis noted in earlier studies that a shift from a weakly negative to a strongly negative wind stress curl over the Weddell Sea is a prerequisite for WSPs to form, together with a large heat reservoir at depth. However, the ultimate trigger is a pronounced MRP, whose associated convection creates high surface salinity anomalies that propagate westward with the flow of the Weddell Gyre. If large enough, these anomalies trigger the formation of a WSP and a pulse of newly formed Antarctic Bottom Water.</jats:p> |
author |
Kurtakoti, Prajvala Veneziani, Milena Stössel, Achim Weijer, Wilbert Maltrud, Mathew |
spellingShingle |
Kurtakoti, Prajvala Veneziani, Milena Stössel, Achim Weijer, Wilbert Maltrud, Mathew On the Generation of Weddell Sea Polynyas in a High-Resolution Earth System Model |
author_facet |
Kurtakoti, Prajvala Veneziani, Milena Stössel, Achim Weijer, Wilbert Maltrud, Mathew |
author_sort |
Kurtakoti, Prajvala |
title |
On the Generation of Weddell Sea Polynyas in a High-Resolution Earth System Model |
title_short |
On the Generation of Weddell Sea Polynyas in a High-Resolution Earth System Model |
title_full |
On the Generation of Weddell Sea Polynyas in a High-Resolution Earth System Model |
title_fullStr |
On the Generation of Weddell Sea Polynyas in a High-Resolution Earth System Model |
title_full_unstemmed |
On the Generation of Weddell Sea Polynyas in a High-Resolution Earth System Model |
title_sort |
on the generation of weddell sea polynyas in a high-resolution earth system model |
publishDate |
2023 |
url |
http://www.osti.gov/servlets/purl/1807832 https://www.osti.gov/biblio/1807832 https://doi.org/10.1175/jcli-d-20-0229.1 |
long_lat |
ENVELOPE(-63.071,-63.071,-70.797,-70.797) ENVELOPE(3.000,3.000,-66.000,-66.000) |
geographic |
Antarctic Weddell Sea Weddell Curl Maud Rise |
geographic_facet |
Antarctic Weddell Sea Weddell Curl Maud Rise |
genre |
Antarc* Antarctic Weddell Sea |
genre_facet |
Antarc* Antarctic Weddell Sea |
op_relation |
http://www.osti.gov/servlets/purl/1807832 https://www.osti.gov/biblio/1807832 https://doi.org/10.1175/jcli-d-20-0229.1 doi:10.1175/jcli-d-20-0229.1 |
op_doi |
https://doi.org/10.1175/jcli-d-20-0229.1 |
container_title |
Journal of Climate |
container_volume |
34 |
container_issue |
7 |
container_start_page |
2491 |
op_container_end_page |
2510 |
_version_ |
1772810127689121792 |