Eddy response to Southern Ocean climate modes
Interannual variations in Southern Ocean eddy kinetic energy (EKE) are investigated using 16 years of altimetric data. Circumpolar averages show a peak in EKE from 2000 to 2002, 2-3 years after the peak in the Southern Annular Mode (SAM) index. Although the SAM forcing is in phase around the circump...
Published in: | Journal of Geophysical Research: Oceans |
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ftanucanberra:oai:openresearch-repository.anu.edu.au:1885/33526 2024-01-14T10:10:49+01:00 Eddy response to Southern Ocean climate modes Morrow, R. Ward, Marshall Hogg, Andrew Pasquet, S. http://hdl.handle.net/1885/33526 https://doi.org/10.1029/2009JC005894 https://openresearch-repository.anu.edu.au/bitstream/1885/33526/5/Ward_-Eddy_respons_to_Southern_Ocean_climate_modes.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/33526/7/01_Morrow_Eddy_response_to_Southern_2010.pdf.jpg unknown American Geophysical Union 0148-0227 http://hdl.handle.net/1885/33526 doi:10.1029/2009JC005894 https://openresearch-repository.anu.edu.au/bitstream/1885/33526/5/Ward_-Eddy_respons_to_Southern_Ocean_climate_modes.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/33526/7/01_Morrow_Eddy_response_to_Southern_2010.pdf.jpg Journal of Geophysical Research Keywords: Altimetric data Energy peaks Heterogeneous distributions In-phase Interannual variation Mean flow Meridional winds Numerical modeling Pacific ocean Southern annular mode Southern Ocean Wind forcing Nickel compounds Oceanography altimeter an Journal article ftanucanberra https://doi.org/10.1029/2009JC005894 2023-12-15T09:36:18Z Interannual variations in Southern Ocean eddy kinetic energy (EKE) are investigated using 16 years of altimetric data. Circumpolar averages show a peak in EKE from 2000 to 2002, 2-3 years after the peak in the Southern Annular Mode (SAM) index. Although the SAM forcing is in phase around the circumpolar band, we find the EKE response varies regionally. The strongest EKE is in the Pacific, with energy peaks occurring progressively later toward the east. We suggest that this is due to the presence of two climate modes: SAM and ENSO. When strong positive SAM events coincide with La Niña periods, as in 1999, anomalous meridional wind forcing is enhanced in the South Pacific Ocean, contributing to the observed increase in EKE 2-3 years later. When positive SAM events coincide with El Niño periods, as in 1993, the climate modes are in opposition in the South Pacific, leading to a weak EKE response during the mid-1990s. Numerical modeling supports these observations. By applying different combinations of SAM and ENSO, we can reproduce both the elevated Pacific EKE response to SAM as well as an additional amplification/suppression of EKE during La Niña/El Niño. In general, we find that the EKE response depends on the interplay between wind forcing, topography, and mean flow and produces a strongly heterogeneous distribution in the Southern Ocean. Article in Journal/Newspaper Southern Ocean Australian National University: ANU Digital Collections Southern Ocean Pacific Journal of Geophysical Research: Oceans 115 C10 |
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Open Polar |
collection |
Australian National University: ANU Digital Collections |
op_collection_id |
ftanucanberra |
language |
unknown |
topic |
Keywords: Altimetric data Energy peaks Heterogeneous distributions In-phase Interannual variation Mean flow Meridional winds Numerical modeling Pacific ocean Southern annular mode Southern Ocean Wind forcing Nickel compounds Oceanography altimeter an |
spellingShingle |
Keywords: Altimetric data Energy peaks Heterogeneous distributions In-phase Interannual variation Mean flow Meridional winds Numerical modeling Pacific ocean Southern annular mode Southern Ocean Wind forcing Nickel compounds Oceanography altimeter an Morrow, R. Ward, Marshall Hogg, Andrew Pasquet, S. Eddy response to Southern Ocean climate modes |
topic_facet |
Keywords: Altimetric data Energy peaks Heterogeneous distributions In-phase Interannual variation Mean flow Meridional winds Numerical modeling Pacific ocean Southern annular mode Southern Ocean Wind forcing Nickel compounds Oceanography altimeter an |
description |
Interannual variations in Southern Ocean eddy kinetic energy (EKE) are investigated using 16 years of altimetric data. Circumpolar averages show a peak in EKE from 2000 to 2002, 2-3 years after the peak in the Southern Annular Mode (SAM) index. Although the SAM forcing is in phase around the circumpolar band, we find the EKE response varies regionally. The strongest EKE is in the Pacific, with energy peaks occurring progressively later toward the east. We suggest that this is due to the presence of two climate modes: SAM and ENSO. When strong positive SAM events coincide with La Niña periods, as in 1999, anomalous meridional wind forcing is enhanced in the South Pacific Ocean, contributing to the observed increase in EKE 2-3 years later. When positive SAM events coincide with El Niño periods, as in 1993, the climate modes are in opposition in the South Pacific, leading to a weak EKE response during the mid-1990s. Numerical modeling supports these observations. By applying different combinations of SAM and ENSO, we can reproduce both the elevated Pacific EKE response to SAM as well as an additional amplification/suppression of EKE during La Niña/El Niño. In general, we find that the EKE response depends on the interplay between wind forcing, topography, and mean flow and produces a strongly heterogeneous distribution in the Southern Ocean. |
format |
Article in Journal/Newspaper |
author |
Morrow, R. Ward, Marshall Hogg, Andrew Pasquet, S. |
author_facet |
Morrow, R. Ward, Marshall Hogg, Andrew Pasquet, S. |
author_sort |
Morrow, R. |
title |
Eddy response to Southern Ocean climate modes |
title_short |
Eddy response to Southern Ocean climate modes |
title_full |
Eddy response to Southern Ocean climate modes |
title_fullStr |
Eddy response to Southern Ocean climate modes |
title_full_unstemmed |
Eddy response to Southern Ocean climate modes |
title_sort |
eddy response to southern ocean climate modes |
publisher |
American Geophysical Union |
url |
http://hdl.handle.net/1885/33526 https://doi.org/10.1029/2009JC005894 https://openresearch-repository.anu.edu.au/bitstream/1885/33526/5/Ward_-Eddy_respons_to_Southern_Ocean_climate_modes.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/33526/7/01_Morrow_Eddy_response_to_Southern_2010.pdf.jpg |
geographic |
Southern Ocean Pacific |
geographic_facet |
Southern Ocean Pacific |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
Journal of Geophysical Research |
op_relation |
0148-0227 http://hdl.handle.net/1885/33526 doi:10.1029/2009JC005894 https://openresearch-repository.anu.edu.au/bitstream/1885/33526/5/Ward_-Eddy_respons_to_Southern_Ocean_climate_modes.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/33526/7/01_Morrow_Eddy_response_to_Southern_2010.pdf.jpg |
op_doi |
https://doi.org/10.1029/2009JC005894 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
115 |
container_issue |
C10 |
_version_ |
1788065653513519104 |