Satellite-derived steric height in the Southern Ocean:  trends, variability, and climate drivers

Cocks, Jennifer; Silvano, Alessandro; Naveira Garabato, Alberto C.; Dragomir, Oana; Schifano, Noémie; Hogg, Anna E.; Marzocchi, Alice

doi:https://doi.org/10.5194/os-21-1609-2025

Articles | Volume 21, issue 4

https://doi.org/10.5194/os-21-1609-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/os-21-1609-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 21, issue 4

Research article

|

30 Jul 2025

Research article |

| 30 Jul 2025

Satellite-derived steric height in the Southern Ocean: trends, variability, and climate drivers

Jennifer Cocks, Alessandro Silvano, Alberto C. Naveira Garabato, Oana Dragomir, Noémie Schifano, Anna E. Hogg, and Alice Marzocchi

Supplement

https://doi.org/10.5194/os-21-1609-2025-supplement

Data sets

Southern Ocean Steric Height Anomaly 2002-2018 Jennifer Cocks and Oana Dragomir https://doi.org/10.5281/zenodo.15282781

NOAA/NSIDC climate data record of passive microwave sea ice concentration W. Meier et al. https://doi.org/10.7265/RJZB-PF78

Trends in the Southern Annular Mode from observations and reanalyses (https://legacy.bas.ac.uk/met/gjma/sam.html0 G. J. Marshall https://doi.org/10.1175/1520-0442%282003%29016<4134%3ATITSAM>2.0.CO%3B2

Southern Ocean steric height anomaly 2002-2018 J. Cocks and O. Dragomir https://doi.org/10.5281/zenodo.15282781

Argo float data and metadata from Global Data Assembly Centre (Argo GDAC) Argo https://doi.org/10.17882/42182

CSR GRACE and GRACE-FO RL06 Mascon Solutions v02 H. Save https://doi.org/10.15781/cgq9-nh24

The GEBCO_2024 Grid - a continuous terrain model of the global oceans and land GEBCO Bathymetric Compilation Group https://doi.org/10.5285/1c44ce99-0a0d-5f4f-e063-7086abc0ea0f

Southern Oscillation Index (SOI) NOAA NCEI - National Centers for Environmental Information https://www.ncei.noaa.gov/access/monitoring/enso/soi#calculation-of-so

Model code and software

eejco/stericheight_2023: Satellite-derived steric height in the Southern Ocean: Trends, variability, and climate drivers Eejco https://doi.org/10.5281/zenodo.16039715

Short summary

Heat and freshwater fluxes in the Southern Ocean mediate global ocean circulation and abyssal ventilation. These fluxes manifest as changes in steric height: sea level anomalies from changes in ocean density. We compute the steric height anomaly of the Southern Ocean using satellite data and validate it against in situ observations. We analyse trends and variability in steric height, drawing links to climate variability, and discuss the effectiveness of the method, highlighting issues with its application.