Dynamics of the Southern Ocean Circulation Off West Antarctica
This thesis presents an investigation of the dynamics of the ocean circulation off West Antarctica, a region characterised by intense ice shelf loss. The Ross Gyre, located in the western side of West Antarctica, is studied through remote sensing techniques that retrieve information of the sea level...
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University of Southampton
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ftsouthampton:oai:eprints.soton.ac.uk:435405 2023-07-30T03:56:01+02:00 Dynamics of the Southern Ocean Circulation Off West Antarctica Segabinazzi Dotto, Tiago 2019-06 text https://eprints.soton.ac.uk/435405/ https://eprints.soton.ac.uk/435405/1/Dotto_2019_PhD_FINAL.pdf en English eng University of Southampton https://eprints.soton.ac.uk/435405/1/Dotto_2019_PhD_FINAL.pdf Segabinazzi Dotto, Tiago (2019) Dynamics of the Southern Ocean Circulation Off West Antarctica. University of Southampton, Doctoral Thesis, 184pp. Thesis NonPeerReviewed 2019 ftsouthampton 2023-07-09T22:32:47Z This thesis presents an investigation of the dynamics of the ocean circulation off West Antarctica, a region characterised by intense ice shelf loss. The Ross Gyre, located in the western side of West Antarctica, is studied through remote sensing techniques that retrieve information of the sea level from sea ice leads. The seasonality of the gyre is driven by the winds through two distinct modes. The first mode, associated with circumpolar winds, reduces sea level at the end of summer through northward Ekman transport. Regional sea level rises in winter due to ice cover, which reduces the wind stress on the ocean. The second mode, associated with the Amundsen Sea Low (ASL), controls the transport and area of the Ross Gyre and the coastal throughflow with a semi-‐ annual period, with peaks in May and November. A deeper ASL allows the gyre’s expansion and intensification, and enhances the westward throughflow. On the eastern side of West Antarctica, warm Circumpolar Deep Water (CDW) inflows to the Amundsen Sea are studied with a regional model and in situ data. The key inflow-‐controlling mechanisms are identified by decomposing CDW temperature variability into two components associated with (1) changes in the depth of isopycnals (heave; HVE), and (2) changes in the temperature of isopycnals (water mass property changes; WMP). In the western Amundsen Sea, the deeper thermocline and shallower shelf break hinder CDW access onto the shelf, and CDW inflow is regulated by the uplift of isopycnals at the shelf break – which is itself controlled by wind-‐driven variations in the speed of an undercurrent flowing eastward along the continental slope. In contrast, the shallower thermocline and deeper shelf break in the eastern Amundsen Sea permit CDW to persistently access the continental shelf, and CDW temperature in the area responds to wind-‐driven modulation of the water mass’ on-‐ shelf volume by changes in the rate of inflow across the shelf break and in Ekman pumping-‐ induced vertical displacement of ... Thesis Amundsen Sea Antarc* Antarctica Ice Shelf Sea ice Southern Ocean West Antarctica University of Southampton: e-Prints Soton Southern Ocean West Antarctica Amundsen Sea |
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Open Polar |
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University of Southampton: e-Prints Soton |
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ftsouthampton |
language |
English |
description |
This thesis presents an investigation of the dynamics of the ocean circulation off West Antarctica, a region characterised by intense ice shelf loss. The Ross Gyre, located in the western side of West Antarctica, is studied through remote sensing techniques that retrieve information of the sea level from sea ice leads. The seasonality of the gyre is driven by the winds through two distinct modes. The first mode, associated with circumpolar winds, reduces sea level at the end of summer through northward Ekman transport. Regional sea level rises in winter due to ice cover, which reduces the wind stress on the ocean. The second mode, associated with the Amundsen Sea Low (ASL), controls the transport and area of the Ross Gyre and the coastal throughflow with a semi-‐ annual period, with peaks in May and November. A deeper ASL allows the gyre’s expansion and intensification, and enhances the westward throughflow. On the eastern side of West Antarctica, warm Circumpolar Deep Water (CDW) inflows to the Amundsen Sea are studied with a regional model and in situ data. The key inflow-‐controlling mechanisms are identified by decomposing CDW temperature variability into two components associated with (1) changes in the depth of isopycnals (heave; HVE), and (2) changes in the temperature of isopycnals (water mass property changes; WMP). In the western Amundsen Sea, the deeper thermocline and shallower shelf break hinder CDW access onto the shelf, and CDW inflow is regulated by the uplift of isopycnals at the shelf break – which is itself controlled by wind-‐driven variations in the speed of an undercurrent flowing eastward along the continental slope. In contrast, the shallower thermocline and deeper shelf break in the eastern Amundsen Sea permit CDW to persistently access the continental shelf, and CDW temperature in the area responds to wind-‐driven modulation of the water mass’ on-‐ shelf volume by changes in the rate of inflow across the shelf break and in Ekman pumping-‐ induced vertical displacement of ... |
format |
Thesis |
author |
Segabinazzi Dotto, Tiago |
spellingShingle |
Segabinazzi Dotto, Tiago Dynamics of the Southern Ocean Circulation Off West Antarctica |
author_facet |
Segabinazzi Dotto, Tiago |
author_sort |
Segabinazzi Dotto, Tiago |
title |
Dynamics of the Southern Ocean Circulation Off West Antarctica |
title_short |
Dynamics of the Southern Ocean Circulation Off West Antarctica |
title_full |
Dynamics of the Southern Ocean Circulation Off West Antarctica |
title_fullStr |
Dynamics of the Southern Ocean Circulation Off West Antarctica |
title_full_unstemmed |
Dynamics of the Southern Ocean Circulation Off West Antarctica |
title_sort |
dynamics of the southern ocean circulation off west antarctica |
publisher |
University of Southampton |
publishDate |
2019 |
url |
https://eprints.soton.ac.uk/435405/ https://eprints.soton.ac.uk/435405/1/Dotto_2019_PhD_FINAL.pdf |
geographic |
Southern Ocean West Antarctica Amundsen Sea |
geographic_facet |
Southern Ocean West Antarctica Amundsen Sea |
genre |
Amundsen Sea Antarc* Antarctica Ice Shelf Sea ice Southern Ocean West Antarctica |
genre_facet |
Amundsen Sea Antarc* Antarctica Ice Shelf Sea ice Southern Ocean West Antarctica |
op_relation |
https://eprints.soton.ac.uk/435405/1/Dotto_2019_PhD_FINAL.pdf Segabinazzi Dotto, Tiago (2019) Dynamics of the Southern Ocean Circulation Off West Antarctica. University of Southampton, Doctoral Thesis, 184pp. |
_version_ |
1772810692374560768 |