Seasonality of warm water intrusions onto the continental shelf near the Totten Glacier
Warm Modified Circumpolar Deep Water (MCDW) from the Southern Ocean drives rapid basal melt of the Totten Ice Shelf on the Sabrina Coast (East Antarctica), affecting the mass balance of the grounded Totten Glacier. Recent observations show that MCDW intrudes onto the continental shelf through a depr...
Published in: | Journal of Geophysical Research: Oceans |
---|---|
Main Authors: | , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Wiley-Blackwell Publishing
2019
|
Subjects: | |
Online Access: | https://espace.library.uq.edu.au/view/UQ:5f00701/UQ5f00701_OA.pdf https://espace.library.uq.edu.au/view/UQ:5f00701 |
id |
ftunivqespace:oai:espace.library.uq.edu.au:UQ:5f00701 |
---|---|
record_format |
openpolar |
spelling |
ftunivqespace:oai:espace.library.uq.edu.au:UQ:5f00701 2023-05-15T13:24:12+02:00 Seasonality of warm water intrusions onto the continental shelf near the Totten Glacier Silvano, Alessandro Rintoul, Stephen R. Kusahara, Kazuya Pena-Molino, Beatriz van Wijk, Esmee Gwyther, David E. Williams, Guy D. 2019-06-01 https://espace.library.uq.edu.au/view/UQ:5f00701/UQ5f00701_OA.pdf https://espace.library.uq.edu.au/view/UQ:5f00701 eng eng Wiley-Blackwell Publishing doi:10.1029/2018JC014634 issn:2169-9275 issn:2169-9291 orcid:0000-0002-7218-2785 Not set Circumpolar Deep-Water Ice Mass-Loss Pine Island Glacier Amundsen Sea Submarine Canyons East Antarctica Circulation Transport Variability Meltwater Journal Article 2019 ftunivqespace https://doi.org/10.1029/2018JC014634 2020-12-08T07:45:46Z Warm Modified Circumpolar Deep Water (MCDW) from the Southern Ocean drives rapid basal melt of the Totten Ice Shelf on the Sabrina Coast (East Antarctica), affecting the mass balance of the grounded Totten Glacier. Recent observations show that MCDW intrudes onto the continental shelf through a depression at the shelf break. Here we investigate such intrusions by combining (1) new oceanographic and bathymetric observations collected for two consecutive years by profiling floats in the depression south of the shelf break, (2) oceanographic measurements collected by conductivity-temperature-depth-instrumented seals on continental slope, and (3) an ocean model. The depression provides a pathway for persistent inflow of warm (0-1 degrees C) MCDW to the inner shelf. In austral autumn and early winter MCDW intrusions were up to 0.5 degrees C warmer and were similar to 75 m thicker than in spring and summer. The seasonality of the flow on the continental slope explains the seasonality of the intrusions. The MCDW layer on the continental slope is warmer and thicker to the east of the depression than to the west. In autumn and early winter a strong, top-to-bottom westward current (Antarctic Slope Current) transports the warmer and thicker MCDW layer along the slope and is diverted poleward at the eastern entrance of the depression. A bottom-intensified eastward current (Antarctic Slope Undercurrent) develops in other months, allowing cooler and thinner intrusions to enter the depression from the west. Our study illustrates how circulation on the Antarctic slope regulates the ocean heat delivery to the continental shelf and ultimately to the ice shelves. Article in Journal/Newspaper Amundsen Sea Antarc* Antarctic Antarctica East Antarctica Ice Shelf Ice Shelves Pine Island Pine Island Glacier Southern Ocean Totten Glacier Totten Ice Shelf The University of Queensland: UQ eSpace Amundsen Sea Antarctic Austral East Antarctica Eastern Entrance ENVELOPE(-132.987,-132.987,69.458,69.458) Glacier Amundsen ENVELOPE(-159.000,-159.000,-85.583,-85.583) Pine Island Glacier ENVELOPE(-101.000,-101.000,-75.000,-75.000) Sabrina Coast ENVELOPE(118.550,118.550,-67.000,-67.000) Southern Ocean The Antarctic Totten Glacier ENVELOPE(116.333,116.333,-66.833,-66.833) Journal of Geophysical Research: Oceans 124 6 4272 4289 |
institution |
Open Polar |
collection |
The University of Queensland: UQ eSpace |
op_collection_id |
ftunivqespace |
language |
English |
topic |
Circumpolar Deep-Water Ice Mass-Loss Pine Island Glacier Amundsen Sea Submarine Canyons East Antarctica Circulation Transport Variability Meltwater |
spellingShingle |
Circumpolar Deep-Water Ice Mass-Loss Pine Island Glacier Amundsen Sea Submarine Canyons East Antarctica Circulation Transport Variability Meltwater Silvano, Alessandro Rintoul, Stephen R. Kusahara, Kazuya Pena-Molino, Beatriz van Wijk, Esmee Gwyther, David E. Williams, Guy D. Seasonality of warm water intrusions onto the continental shelf near the Totten Glacier |
topic_facet |
Circumpolar Deep-Water Ice Mass-Loss Pine Island Glacier Amundsen Sea Submarine Canyons East Antarctica Circulation Transport Variability Meltwater |
description |
Warm Modified Circumpolar Deep Water (MCDW) from the Southern Ocean drives rapid basal melt of the Totten Ice Shelf on the Sabrina Coast (East Antarctica), affecting the mass balance of the grounded Totten Glacier. Recent observations show that MCDW intrudes onto the continental shelf through a depression at the shelf break. Here we investigate such intrusions by combining (1) new oceanographic and bathymetric observations collected for two consecutive years by profiling floats in the depression south of the shelf break, (2) oceanographic measurements collected by conductivity-temperature-depth-instrumented seals on continental slope, and (3) an ocean model. The depression provides a pathway for persistent inflow of warm (0-1 degrees C) MCDW to the inner shelf. In austral autumn and early winter MCDW intrusions were up to 0.5 degrees C warmer and were similar to 75 m thicker than in spring and summer. The seasonality of the flow on the continental slope explains the seasonality of the intrusions. The MCDW layer on the continental slope is warmer and thicker to the east of the depression than to the west. In autumn and early winter a strong, top-to-bottom westward current (Antarctic Slope Current) transports the warmer and thicker MCDW layer along the slope and is diverted poleward at the eastern entrance of the depression. A bottom-intensified eastward current (Antarctic Slope Undercurrent) develops in other months, allowing cooler and thinner intrusions to enter the depression from the west. Our study illustrates how circulation on the Antarctic slope regulates the ocean heat delivery to the continental shelf and ultimately to the ice shelves. |
format |
Article in Journal/Newspaper |
author |
Silvano, Alessandro Rintoul, Stephen R. Kusahara, Kazuya Pena-Molino, Beatriz van Wijk, Esmee Gwyther, David E. Williams, Guy D. |
author_facet |
Silvano, Alessandro Rintoul, Stephen R. Kusahara, Kazuya Pena-Molino, Beatriz van Wijk, Esmee Gwyther, David E. Williams, Guy D. |
author_sort |
Silvano, Alessandro |
title |
Seasonality of warm water intrusions onto the continental shelf near the Totten Glacier |
title_short |
Seasonality of warm water intrusions onto the continental shelf near the Totten Glacier |
title_full |
Seasonality of warm water intrusions onto the continental shelf near the Totten Glacier |
title_fullStr |
Seasonality of warm water intrusions onto the continental shelf near the Totten Glacier |
title_full_unstemmed |
Seasonality of warm water intrusions onto the continental shelf near the Totten Glacier |
title_sort |
seasonality of warm water intrusions onto the continental shelf near the totten glacier |
publisher |
Wiley-Blackwell Publishing |
publishDate |
2019 |
url |
https://espace.library.uq.edu.au/view/UQ:5f00701/UQ5f00701_OA.pdf https://espace.library.uq.edu.au/view/UQ:5f00701 |
long_lat |
ENVELOPE(-132.987,-132.987,69.458,69.458) ENVELOPE(-159.000,-159.000,-85.583,-85.583) ENVELOPE(-101.000,-101.000,-75.000,-75.000) ENVELOPE(118.550,118.550,-67.000,-67.000) ENVELOPE(116.333,116.333,-66.833,-66.833) |
geographic |
Amundsen Sea Antarctic Austral East Antarctica Eastern Entrance Glacier Amundsen Pine Island Glacier Sabrina Coast Southern Ocean The Antarctic Totten Glacier |
geographic_facet |
Amundsen Sea Antarctic Austral East Antarctica Eastern Entrance Glacier Amundsen Pine Island Glacier Sabrina Coast Southern Ocean The Antarctic Totten Glacier |
genre |
Amundsen Sea Antarc* Antarctic Antarctica East Antarctica Ice Shelf Ice Shelves Pine Island Pine Island Glacier Southern Ocean Totten Glacier Totten Ice Shelf |
genre_facet |
Amundsen Sea Antarc* Antarctic Antarctica East Antarctica Ice Shelf Ice Shelves Pine Island Pine Island Glacier Southern Ocean Totten Glacier Totten Ice Shelf |
op_relation |
doi:10.1029/2018JC014634 issn:2169-9275 issn:2169-9291 orcid:0000-0002-7218-2785 Not set |
op_doi |
https://doi.org/10.1029/2018JC014634 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
124 |
container_issue |
6 |
container_start_page |
4272 |
op_container_end_page |
4289 |
_version_ |
1766377985311506432 |