Meridional volume transport in the South Pacific: Mean and SAM-related variability
The large increase in upper-ocean sampling during the past decade enables improved estimation of the mean meridional volume transport in the midlatitude South Pacific, and hence of the climatically important Meridional Overturning Circulation. Transport is computed using Argo float profile data for...
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ftcdlib:oai:escholarship.org/ark:/13030/qt2927d8qp 2023-05-15T13:33:01+02:00 Meridional volume transport in the South Pacific: Mean and SAM-related variability Zilberman, NV Roemmich, DH Gille, ST 2658 - 2678 2014-01-01 application/pdf https://escholarship.org/uc/item/2927d8qp unknown eScholarship, University of California qt2927d8qp https://escholarship.org/uc/item/2927d8qp public Journal of Geophysical Research: Oceans, vol 119, iss 4 volume transport Southern Pacific Ocean water mass Argo ENSO SAM Geophysics Oceanography Physical Geography and Environmental Geoscience article 2014 ftcdlib 2021-02-18T15:14:38Z The large increase in upper-ocean sampling during the past decade enables improved estimation of the mean meridional volume transport in the midlatitude South Pacific, and hence of the climatically important Meridional Overturning Circulation. Transport is computed using Argo float profile data for geostrophic shear and trajectory data for reference velocities at 1000 m. For the period 2004-2012, the mean geostrophic transport across 32S is 20.6 ± 6.0 Sv in the top 2000 m of the ocean. From west to east, this includes the southward East Australian Current (23.3 ± 2.9 Sv), its northward recirculation (16.3 ± 3.6 Sv), the broad interior northward flow (18.4 ± 4.1 Sv), and the net northward flow (9.2 ± 2.2 Sv) in opposing currents in the eastern Pacific. The basin-integrated geostrophic transport includes 7.3 ± 0.9 Sv of surface and thermocline waters, 4.9 ± 1.0 Sv of Subantarctic Mode Water, and 4.9 ± 1.4 Sv of Antarctic Intermediate Water. Interannual variability in volume transport across 32S in the South Pacific shows a Southern Annual Mode signature characterized by an increase during the positive phase of the Southern Annular Mode and a decrease during the negative phase. Maximum amplitudes in geostrophic transport anomalies, seen in the East Australian Current and East Australian Current recirculation, are consistent with wind stress curl anomalies near the western boundary. Key Points Improved meridional volume transport in the South Pacific using Argo EAC transport variability tied to the SAM © Published 2014. This article is a U.S. Government work and is in the public domain in the USA. Article in Journal/Newspaper Antarc* Antarctic University of California: eScholarship Antarctic Curl ENVELOPE(-63.071,-63.071,-70.797,-70.797) Pacific |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
unknown |
topic |
volume transport Southern Pacific Ocean water mass Argo ENSO SAM Geophysics Oceanography Physical Geography and Environmental Geoscience |
spellingShingle |
volume transport Southern Pacific Ocean water mass Argo ENSO SAM Geophysics Oceanography Physical Geography and Environmental Geoscience Zilberman, NV Roemmich, DH Gille, ST Meridional volume transport in the South Pacific: Mean and SAM-related variability |
topic_facet |
volume transport Southern Pacific Ocean water mass Argo ENSO SAM Geophysics Oceanography Physical Geography and Environmental Geoscience |
description |
The large increase in upper-ocean sampling during the past decade enables improved estimation of the mean meridional volume transport in the midlatitude South Pacific, and hence of the climatically important Meridional Overturning Circulation. Transport is computed using Argo float profile data for geostrophic shear and trajectory data for reference velocities at 1000 m. For the period 2004-2012, the mean geostrophic transport across 32S is 20.6 ± 6.0 Sv in the top 2000 m of the ocean. From west to east, this includes the southward East Australian Current (23.3 ± 2.9 Sv), its northward recirculation (16.3 ± 3.6 Sv), the broad interior northward flow (18.4 ± 4.1 Sv), and the net northward flow (9.2 ± 2.2 Sv) in opposing currents in the eastern Pacific. The basin-integrated geostrophic transport includes 7.3 ± 0.9 Sv of surface and thermocline waters, 4.9 ± 1.0 Sv of Subantarctic Mode Water, and 4.9 ± 1.4 Sv of Antarctic Intermediate Water. Interannual variability in volume transport across 32S in the South Pacific shows a Southern Annual Mode signature characterized by an increase during the positive phase of the Southern Annular Mode and a decrease during the negative phase. Maximum amplitudes in geostrophic transport anomalies, seen in the East Australian Current and East Australian Current recirculation, are consistent with wind stress curl anomalies near the western boundary. Key Points Improved meridional volume transport in the South Pacific using Argo EAC transport variability tied to the SAM © Published 2014. This article is a U.S. Government work and is in the public domain in the USA. |
format |
Article in Journal/Newspaper |
author |
Zilberman, NV Roemmich, DH Gille, ST |
author_facet |
Zilberman, NV Roemmich, DH Gille, ST |
author_sort |
Zilberman, NV |
title |
Meridional volume transport in the South Pacific: Mean and SAM-related variability |
title_short |
Meridional volume transport in the South Pacific: Mean and SAM-related variability |
title_full |
Meridional volume transport in the South Pacific: Mean and SAM-related variability |
title_fullStr |
Meridional volume transport in the South Pacific: Mean and SAM-related variability |
title_full_unstemmed |
Meridional volume transport in the South Pacific: Mean and SAM-related variability |
title_sort |
meridional volume transport in the south pacific: mean and sam-related variability |
publisher |
eScholarship, University of California |
publishDate |
2014 |
url |
https://escholarship.org/uc/item/2927d8qp |
op_coverage |
2658 - 2678 |
long_lat |
ENVELOPE(-63.071,-63.071,-70.797,-70.797) |
geographic |
Antarctic Curl Pacific |
geographic_facet |
Antarctic Curl Pacific |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
Journal of Geophysical Research: Oceans, vol 119, iss 4 |
op_relation |
qt2927d8qp https://escholarship.org/uc/item/2927d8qp |
op_rights |
public |
_version_ |
1766037854752866304 |