Antarctic Thermocline Dynamics along a Narrow Shelf with Easterly Winds
Determining the role of Southern Ocean warm intermediate water for driving melting of the Antarctic ice sheet is a major challenge in assessing future sea level rise. Analysis of 2859 CTD profiles obtained between 1977 and 2016 by ships and instrumented seals at the Weddell Sea continental slope rev...
Published in: | Journal of Physical Oceanography |
---|---|
Main Author: | |
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
2018
|
Subjects: | |
Online Access: | https://epic.awi.de/id/eprint/48202/ https://epic.awi.de/id/eprint/48202/1/Hattermann_JPO-2018.pdf https://doi.org/10.1175/JPO-D-18-0064.1 https://hdl.handle.net/10013/epic.eea13e81-3df6-497b-bd43-f79bb710371a |
id |
ftawi:oai:epic.awi.de:48202 |
---|---|
record_format |
openpolar |
spelling |
ftawi:oai:epic.awi.de:48202 2024-09-15T17:44:22+00:00 Antarctic Thermocline Dynamics along a Narrow Shelf with Easterly Winds Hattermann, Tore 2018 application/pdf https://epic.awi.de/id/eprint/48202/ https://epic.awi.de/id/eprint/48202/1/Hattermann_JPO-2018.pdf https://doi.org/10.1175/JPO-D-18-0064.1 https://hdl.handle.net/10013/epic.eea13e81-3df6-497b-bd43-f79bb710371a unknown https://epic.awi.de/id/eprint/48202/1/Hattermann_JPO-2018.pdf Hattermann, T. (2018) Antarctic Thermocline Dynamics along a Narrow Shelf with Easterly Winds , Journal of Physical Oceanography, 48 (10), pp. 2419-2443 . doi:10.1175/JPO-D-18-0064.1 <https://doi.org/10.1175/JPO-D-18-0064.1> , hdl:10013/epic.eea13e81-3df6-497b-bd43-f79bb710371a EPIC3Journal of Physical Oceanography, 48(10), pp. 2419-2443, ISSN: 0022-3670 Article isiRev 2018 ftawi https://doi.org/10.1175/JPO-D-18-0064.1 2024-06-24T04:21:00Z Determining the role of Southern Ocean warm intermediate water for driving melting of the Antarctic ice sheet is a major challenge in assessing future sea level rise. Analysis of 2859 CTD profiles obtained between 1977 and 2016 by ships and instrumented seals at the Weddell Sea continental slope reveals a seasonal rise of the Antarctic Slope Front thermocline by more than 100 m during the summer. The signal at Kapp Norvegia (17°W) corresponds with a seasonal warming downstream at the Filchner Trough (40°W), indicating that a coherent evolution of the slope front along the shelf break regulates the onshore flow of warm deep water. Climatological cross sections of the slope front hydrography show that downwelling of Antarctic Surface Water forms a secondary front above the warm deep water interface during summer. Enhanced baroclinic growth rates at this front suggest that the wind-driven suppression of the thermocline is partially compensated by a shallower eddy overturning cell when surface water is present. A simple model of the Weddell Gyre boundary current reveals that wintertime densification of surface waters is crucial for maintaining the deep thermocline along the eastern Weddell Sea coast. The sensitivity of the warm inflow to the cross-frontal density gradient implies a positive feedback with ice shelf melting that may lead to an abrupt transition into a high melting state once warm water rises over the shelf break depth. Despite its regional focus, this study highlights the role of upper ocean buoyancy fluxes for controlling the thermocline depth along seasonally ice-covered narrow shelf regions with cyclonic along-slope winds. Article in Journal/Newspaper Antarc* Antarctic Ice Sheet Ice Shelf Southern Ocean Weddell Sea Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Journal of Physical Oceanography 48 10 2419 2443 |
institution |
Open Polar |
collection |
Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
op_collection_id |
ftawi |
language |
unknown |
description |
Determining the role of Southern Ocean warm intermediate water for driving melting of the Antarctic ice sheet is a major challenge in assessing future sea level rise. Analysis of 2859 CTD profiles obtained between 1977 and 2016 by ships and instrumented seals at the Weddell Sea continental slope reveals a seasonal rise of the Antarctic Slope Front thermocline by more than 100 m during the summer. The signal at Kapp Norvegia (17°W) corresponds with a seasonal warming downstream at the Filchner Trough (40°W), indicating that a coherent evolution of the slope front along the shelf break regulates the onshore flow of warm deep water. Climatological cross sections of the slope front hydrography show that downwelling of Antarctic Surface Water forms a secondary front above the warm deep water interface during summer. Enhanced baroclinic growth rates at this front suggest that the wind-driven suppression of the thermocline is partially compensated by a shallower eddy overturning cell when surface water is present. A simple model of the Weddell Gyre boundary current reveals that wintertime densification of surface waters is crucial for maintaining the deep thermocline along the eastern Weddell Sea coast. The sensitivity of the warm inflow to the cross-frontal density gradient implies a positive feedback with ice shelf melting that may lead to an abrupt transition into a high melting state once warm water rises over the shelf break depth. Despite its regional focus, this study highlights the role of upper ocean buoyancy fluxes for controlling the thermocline depth along seasonally ice-covered narrow shelf regions with cyclonic along-slope winds. |
format |
Article in Journal/Newspaper |
author |
Hattermann, Tore |
spellingShingle |
Hattermann, Tore Antarctic Thermocline Dynamics along a Narrow Shelf with Easterly Winds |
author_facet |
Hattermann, Tore |
author_sort |
Hattermann, Tore |
title |
Antarctic Thermocline Dynamics along a Narrow Shelf with Easterly Winds |
title_short |
Antarctic Thermocline Dynamics along a Narrow Shelf with Easterly Winds |
title_full |
Antarctic Thermocline Dynamics along a Narrow Shelf with Easterly Winds |
title_fullStr |
Antarctic Thermocline Dynamics along a Narrow Shelf with Easterly Winds |
title_full_unstemmed |
Antarctic Thermocline Dynamics along a Narrow Shelf with Easterly Winds |
title_sort |
antarctic thermocline dynamics along a narrow shelf with easterly winds |
publishDate |
2018 |
url |
https://epic.awi.de/id/eprint/48202/ https://epic.awi.de/id/eprint/48202/1/Hattermann_JPO-2018.pdf https://doi.org/10.1175/JPO-D-18-0064.1 https://hdl.handle.net/10013/epic.eea13e81-3df6-497b-bd43-f79bb710371a |
genre |
Antarc* Antarctic Ice Sheet Ice Shelf Southern Ocean Weddell Sea |
genre_facet |
Antarc* Antarctic Ice Sheet Ice Shelf Southern Ocean Weddell Sea |
op_source |
EPIC3Journal of Physical Oceanography, 48(10), pp. 2419-2443, ISSN: 0022-3670 |
op_relation |
https://epic.awi.de/id/eprint/48202/1/Hattermann_JPO-2018.pdf Hattermann, T. (2018) Antarctic Thermocline Dynamics along a Narrow Shelf with Easterly Winds , Journal of Physical Oceanography, 48 (10), pp. 2419-2443 . doi:10.1175/JPO-D-18-0064.1 <https://doi.org/10.1175/JPO-D-18-0064.1> , hdl:10013/epic.eea13e81-3df6-497b-bd43-f79bb710371a |
op_doi |
https://doi.org/10.1175/JPO-D-18-0064.1 |
container_title |
Journal of Physical Oceanography |
container_volume |
48 |
container_issue |
10 |
container_start_page |
2419 |
op_container_end_page |
2443 |
_version_ |
1810491898504151040 |