Abstract
Over recent decades, the Southern Ocean’s westerly winds have intensified and shifted poleward, whereas the Antarctic Circumpolar Current (ACC) transport through the Drake Passage has remained stable. Here using satellite altimetry data, we define the interannual evolution of the ACC’s dynamical boundaries and identify a significant southward shift of its Northern Boundary (NB) over the past three decades, with the most rapid migration (up to 1.1° per decade) occurring in the Southeast Pacific. Ocean reanalysis confirms that volume transport within the ACC’s boundaries remains stable across the circumpolar Southern Ocean, despite a strengthening eastward flow concentrated near the migrating NB. The migrating NB redirects this intensified flow into the subtropical gyre, strengthening the Southern Ocean supergyre while maintaining stable ACC transport. These results resolve the paradox of stronger zonal flows coexisting with stable ACC transport, providing insight into changing Southern Ocean dynamics and their climate implications.
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Data availability
All the data analysed here are openly available. Mean dynamic topography (MDT) and altimeter satellite gridded sea level anomalies (SLA) data are available from https://doi.org/10.48670/moi-00150 and https://doi.org/10.48670/moi-00145. The latest version of IAP data were downloaded from http://www.ocean.iap.ac.cn/pages/dataService/dataService.html?navAnchor=dataService. ERA5 monthly averaged data are provided by Copernicus Climate Change Service (C3S) Climate Data Store (CDS) at https://doi.org/10.24381/cds.f17050d7. Global Ocean Ensemble Physics Reanalysis (GOEPR) is available from https://doi.org/10.48670/moi-00024. The processed data and analysis code that support the findings of this study are available in a reproducible computing environment on Code Ocean: https://codeocean.com/capsule/6410ad70-0e0c-4628-a7cc-c2af0d3596ac/. This capsule includes all datasets and the computational environment required to reproduce the results reported in this paper. The raw data were derived from publicly available sources available via Code Ocean at https://doi.org/10.24433/CO.4603944.v2 (ref. 45). Source data are provided with this paper.
Code availability
The analysis code that support the findings of this study are available in a reproducible computing environment on Code Ocean: https://codeocean.com/capsule/6410ad70-0e0c-4628-a7cc-c2af0d3596ac/. This capsule includes all scripts required to reproduce the results reported in this paper.
References
Marshall, J. & Radko, T. Residual-mean solutions for the Antarctic Circumpolar Current and its associated overturning circulation. J. Phys. Oceanogr. 33, 2341–2354 (2003).
Gutierrez-Villanueva, M. O., Chereskin, T. K. & Sprintall, J. Compensating transport trends in the Drake Passage frontal regions yield no acceleration in net transport. Nat. Commun. 14, 7792 (2023).
Farneti, R., Delworth, T. L., Rosati, A. J., Griffies, S. M. & Zeng, F. The role of mesoscale eddies in the rectification of the Southern Ocean response to climate change. J. Phys. Oceanogr. 40, 1539–1557 (2010).
Shi, J.-R., Talley, L. D., Xie, S.-P., Peng, Q. & Liu, W. Ocean warming and accelerating Southern Ocean zonal flow. Nat. Clim. Change 11, 1090–1097 (2021).
Sigmond, M., Reader, M. C., Fyfe, J. C. & Gillett, N. P. Drivers of past and future Southern Ocean change: stratospheric ozone versus greenhouse gas impacts. Geophys. Res. Lett. 38, L12601 (2011).
Swart, N. C., Gille, S. T., Fyfe, J. C. & Gillett, N. P. Recent Southern Ocean warming and freshening driven by greenhouse gas emissions and ozone depletion. Nat. Geosci. 11, 836–841 (2018).
Koenig, Z., Provost, C., Ferrari, R., Sennéchael, N. & Rio, M. H. Volume transport of the Antarctic Circumpolar Current: production and validation of a 20 year long time series obtained from in situ and satellite observations. J. Geophys. Res. Oceans 119, 5407–5433 (2014).
Tracey, K. L., Watts, D. R., Donohue, K. A. & Chidichimo, M. P. Baroclinic transport time series of the Antarctic Circumpolar Current measured in Drake Passage. J. Phys. Oceanogr. 44, 1829–1853 (2014).
Xu, X., Chassignet, E. P., Firing, Y. L. & Donohue, K. Antarctic Circumpolar Current transport through Drake Passage: what can we learn from comparing high-resolution model results to observations?. J. Geophys. Res. Oceans 125, e2020JC016365 (2020).
Donohue, K. A., Tracey, K. L., Watts, D. R., Chidichimo, M. P. & Chereskin, T. K. Mean Antarctic Circumpolar Current transport measured in Drake Passage. Geophys. Res. Lett. 43, 11760–11767 (2016).
Jouanno, J. & Capet, X. Connecting flow–topography interactions, vorticity balance, baroclinic instability and transport in the Southern Ocean: the case of an idealized storm track. Ocean Sci. 16, 1207–1223 (2020).
Matsuta, T. et al. Enhanced eddy activity along the Subantarctic Front under intensified westerly winds. Ocean Dyn. 74, 967–986 (2024).
Meredith, M. P. & Hogg, A. M. Circumpolar response of Southern Ocean eddy activity to a change in the Southern Annular Mode. Geophys. Res. Lett. 33, L16608 (2006).
Hogg, A. M. & Downes, S. M. Southern Ocean circulation and eddy compensation in CMIP5 models. J. Clim. 26, 7198–7220 (2013).
Stewart, A. L., Neumann, N. K. & Solodoch, A. “Eddy” saturation of the Antarctic Circumpolar Current by standing waves. J. Phys. Oceanogr. 53, 1161–1181 (2023).
Thompson, A. F. & Naveira Garabato, A. C. Equilibration of the Antarctic Circumpolar Current by standing meanders. J. Phys. Oceanogr. 44, 1811–1828 (2014).
Munday, D. R., Johnson, H. L. & Marshall, D. P. Eddy saturation of equilibrated circumpolar currents. J. Phys. Oceanogr. 43, 507–532 (2013).
Nadeau, L.-P. & Ferrari, R. The role of closed gyres in setting the zonal transport of the Antarctic Circumpolar Current. J. Phys. Oceanogr. 45, 1491–1509 (2015).
Munday, D. R., Johnson, H. L. & Marshall, D. P. Impacts and effects of mesoscale ocean eddies on ocean carbon storage and atmospheric pCO2. Glob. Biogeochem. Cycles 28, 877–896 (2014).
Hogg, A. M.cC. & Morrison, A. K. On the relationship between Southern Ocean overturning and ACC transport. J. Phys. Oceanogr. 43, 140–148 (2013).
Frölicher, T. L. et al. Dominance of the Southern Ocean in anthropogenic carbon and heat uptake in CMIP5 models. J. Clim. 28, 862–886 (2015).
Sallée, J.-B. Southern Ocean warming. Oceanography 31, 52–62 (2018).
Meredith, M. P., Naveira Garabato, A. C., Hogg, A. M. & Farneti, R. Sensitivity of the overturning circulation in the Southern Ocean to decadal changes in wind forcing. J. Clim. 25, 99–110 (2012).
Farneti, R. & Vallis, G. K. Meridional energy transport in the coupled Aatmosphere–ocean system: compensation and partitioning. J. Clim. 26, 7151–7166 (2013).
Yang, H. et al. Poleward shift of the major ocean gyres detected in a warming climate. Geophys. Res. Lett. 47, e2019GL085868 (2020).
Yang, H. et al. Tropical expansion driven by poleward advancing midlatitude meridional temperature gradients. J. Geophys. Res. Atmos. 125, e2020JD033158 (2020).
Cai, W. Antarctic ozone depletion causes an intensification of the Southern Ocean super-gyre circulation. Geophys. Res. Lett. 33, L03712 (2006).
Luis, A. J. & Pandey, P. C. Seasonal variability of QSCAT-derived wind stress over the Southern Ocean. Geophys. Res. Lett. 31, L13304 (2004).
Lauderdale, J. M., Naveira Garabato, A. C., Oliver, K. I. C. & Thomas, L. N. Climatic variations of the work done by the wind on the ocean’s general circulation. J. Geophys. Res. Oceans 117, C09017 (2012).
Sokolov, S. & Rintoul, S. R. Circumpolar structure and distribution of the Antarctic Circumpolar Current fronts: 1. Mean circumpolar paths. J. Geophys. Res. Oceans 114, C11018 (2009).
Sokolov, S. & Rintoul, S. R. Circumpolar structure and distribution of the Antarctic Circumpolar Current fronts: 2. Variability and relationship to sea surface height. J. Geophys. Res. Oceans 114, C11019 (2009).
Kim, Y. S. & Orsi, A. H. On the variability of Antarctic Circumpolar Current fronts inferred from 1992–2011 altimetry. J. Phys. Oceanogr. 44, 3054–3071 (2014).
Tarakanov, R. Y. & Gritsenko, A. M. Fine-jet structure of the Antarctic Circumpolar Current south of Africa. Oceanol 54, 677–687 (2014).
Park, Y. H. et al. Observations of the Antarctic Circumpolar Current over the Udintsev Fracture Zone, the narrowest choke point in the Southern Ocean. J. Geophys. Res. Oceans 124, 4511–4528 (2019).
Armour, K. C., Marshall, J., Scott, J. R., Donohoe, A. & Newsom, E. R. Southern Ocean warming delayed by circumpolar upwelling and equatorward transport. Nat. Geosci. 9, 549–554 (2016).
Shi, J.-R., Xie, S.-P. & Talley, L. D. Evolving relative importance of the Southern Ocean and North Atlantic in anthropogenic ocean heat uptake. J. Clim. 31, 7459–7479 (2018).
Sallée, J. B., Speer, K. & Morrow, R. Response of the Antarctic Circumpolar Current to atmospheric variability. J. Clim. 21, 3020–3039 (2008).
Chapman, C. C. New perspectives on frontal variability in the Southern Ocean. J. Phys. Oceanogr. 47, 1151–1168 (2017).
Mulet, S. et al. The new CNES-CLS18 Global Mean Dynamic Topography. Ocean Sci. 17, 789–808 (2020).
Global Ocean Mean Dynamic Topography. Copernicus Marine Service https://doi.org/10.48670/moi-00150 (2024).
Global Ocean Gridded L 4 Sea Surface Heights And Derived Variables Reprocessed. Copernicus Marine Service https://doi.org/10.48670/moi-00145 (2024).
Cheng, L., Zhu, J., Cowley, R., Boyer, T. & Wijffels, S. Time, probe type, and temperature variable bias corrections to historical expendable bathythermograph observations. J. Atmos. Ocean. Technol. 31, 1793–1825 (2014).
Hersbach, H. et al. The ERA5 global reanalysis. Q. J. R. Meteorol. Soc. 146, 1999–2049 (2020).
Global Ocean Ensemble Physics Reanalysis. Copernicus Marine Service https://doi.org/10.48670/moi-00024 (2024).
Xie, C. et al. Southward shift of the Antarctic Circumpolar Current upstream of Drake Passage maintains a stable circumpolar transport: processed data and plotting code. Code Ocean https://doi.org/10.24433/CO.6837058 (2025).
Acknowledgements
We thank Z. Zhang for valuable discussions. This work was supported by the National Natural Science Foundation of China (grant no. 42376256) and the Chinese Arctic and Antarctic Administration (grant no. IRASCC 01-01-01 C). D.L. is supported by the National Natural Science Foundation of China (grant no. 42306021).
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C.X. conceived the initial idea, analysed the data, plotted the figures and wrote the initial manuscript. J.S. led the research and improved the manuscript. D.L. contributed to the research design and provided guidance on figure preparation. Y.S. provided conceptual advice on the research design. J.J. contributed to the research direction and provided expert feedback on figure preparation. G.D. reviewed the manuscript and provided critical revisions to improve its clarity and accuracy.
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Extended data
Extended Data Fig. 1 Trends in Zonal Wind Intensity over the Southern Hemisphere (1993–2022).
(a) The spatial distribution of the zonal wind trend. (b) The zonal-mean zonal wind trend for different oceanic regions. Basemap data in a from the GSHHG (https://www.soest.hawaii.edu/pwessel/gshhg/).
Extended Data Fig. 2 Comparison of the trends between zonal westerlies and the NB (northern boundary).
(a) Trends in the position of the ACC northern boundary, the northern edge of the westerly wind belt (zero line), the core latitude of the westerlies, and the westerly wind intensity. Hollow (solid) circles indicate trends that are statistically significant at the 95% confidence level.(b) Interannual variability of the northern boundary of the westerlies and the ACC northern boundary. Basemap data in b from the GSHHG (https://www.soest.hawaii.edu/pwessel/gshhg/) with bathymetry and topography data from ETOPO2022 (NOAA NCEI, https://www.ncei.noaa.gov/products/etopo-global-relief-model).
Extended Data Fig. 3 Trends in SST over the Southern Hemisphere (1993–2022).
(a) The spatial distribution of SST. (b) The zonally averaged SST trends for different oceanic regions. Basemap data in a from the GSHHG (https://www.soest.hawaii.edu/pwessel/gshhg/), bathymetry and topography data in b from ETOPO2022 (NOAA NCEI, https://www.ncei.noaa.gov/products/etopo-global-relief-model).
Extended Data Fig. 4 Trends in zonal and meridional flows in the Southeast Pacific (120°W–76°W) based on zonally averaged.
(a) Trend of zonal geostrophic flow from IAP, plotted along streamlines using the SSH contour corresponding to the NB as the origin. (b) Trend of zonally averaged zonal flow from GOEPR.
Extended Data Fig. 5 Changes in the depth-averaged flow velocity over the upper 2000 m near the southern (northern) boundary of the ACC.
(a) and (b) show the variations in mean flow velocity near the Southern Boundary (red line: from -1.12 m to -0.52 m) and Northern Boundary (blue line: from 0 m to 0.6 m) after regressing IAP and GOERP data onto SSH contours.
Extended Data Fig. 6 Variability in meridional transport along the 40°S section (120°W–76°W).
Variability in meridional transport along the 40°S section (120°W–76°W), derived from IAP (a) and GOEPR (b) data, respectively.
Extended Data Fig. 7 Spatiotemporal distribution and trends of wind stress curl in the Southern Hemisphere (1993-2022).
(a) The spatial distribution of wind stress curl, with black curves denoting the zero wind stress curl contour. (b) The zonal-mean wind stress curl (blue curve) and its trend (red curve) in the Southern Hemisphere. (c) The wind stress curl trend, with the black curve as in (a). (d) The zonal-mean wind stress curl trend in the Southern Hemisphere. Basemap data in a and c from the GSHHG (https://www.soest.hawaii.edu/pwessel/gshhg/) with bathymetry and topography data from ETOPO2022 (NOAA NCEI, https://www.ncei.noaa.gov/products/etopo-global-relief-model).
Extended Data Fig. 8 Meridional Shifts of Southern Hemisphere Subtropical Gyre and the ACC Position (1993–2022).
(a) Parameterized calculation regions for the center positions of the subtropical gyres and the ACC in each ocean basin, calculated following the method of Yang et al.25. (b) Meridional shifts of the Southern Hemisphere Subtropical Gyre and the ACC position. (c) Meridional velocity of the ACC’s Northern Boundary. Basemap data in a from the GSHHG (https://www.soest.hawaii.edu/pwessel/gshhg/).
Source data
Source Data Fig. 1
Source data for Fig. 1. This file contains processed datasets used to generate maps of MDT, ACC front positions, meridional boundary time series and meridional sections of zonal velocity (mean fields, linear trends, significance tests and contour/section plots). Detailed descriptions for each sheet are provided within the file as internal titles, footnotes or legends.
Source Data Fig. 2
Source data for Fig. 2. Includes raw data used to generate the line plots and calculate the trends.
Source Data Fig. 3
Source data for Fig. 3. This file contains meridional displacement trends, boundary position time series and Lagrangian particle trajectory data for the Antarctic Circumpolar Current. Detailed descriptions for each sheet are provided within the file as internal titles, footnotes or legends. Additional topographic and boundary datasets are supplied separately due to file size limitations.
Source Data Fig. 4
Source data for Fig. 4. This file contains volume transport time series and trend analyses across the Northern Boundary in the Southeast Pacific, derived from the IAP and GOCE datasets. Detailed descriptions for each sheet are provided within the file as internal titles, footnotes or legends.
Source Data Fig. 5
Source data for Fig. 5. This file contains processed datasets used to generate the wind stress curl fields, zonal profiles, boundary positions, particle trajectories and geospatial masks in the figure. Detailed descriptions for each sheet are provided within the file as internal titles, footnotes or legends.
Source Data Extended Data Fig. 1
Source data for Extended Data Fig. 1. The data file includes processed zonal wind trend analyses over the Southern Ocean. Detailed descriptions for each sheet are provided within the file as internal titles, footnotes or legends.
Source Data Extended Data Fig. 2
Source data for Extended Data Fig. 2. This file contains aggregated datasets supporting the analysis of meridional displacement trends, geospatial boundaries and positional coordinates related to westerly wind systems. Statistical significance tests and topographical data are also included. For detailed information on individual sheets, refer to the sheet titles, footnotes or legends provided within each sheet.
Source Data Extended Data Fig. 3
Source data for Extended Data Fig. 3. This dataset includes multiple analyses of sea surface temperature (SST) trends, encompassing spatial distribution, statistical significance and zonal averages. It provides insights into geographical patterns and latitudinal profiles of SST changes over time, along with their statistical reliability, derived from comprehensive trend analysis and significance testing.
Source Data Extended Data Fig. 4
Source data for Extended Data Fig. 4. This file contains multiple datasets used to analyze and visualize the linear trends, significance testing results and mean fields of zonal velocity around the Northern Boundary, utilizing both the IAP and GOCE datasets. Each dataset corresponds to specific analyses presented in the figure.
Source Data Extended Data Fig. 5
Source data for Extended Data Fig. 5. Raw data for the interannual variability of zonal flow near the Southern Boundary (SB) and Northern Boundary (NB), derived from the IAP and GOCE datasets.
Source Data Extended Data Fig. 6
Source data for Extended Data Fig. 6. Raw data used to calculate volume transport changes across the 40°S section in the Southeast Pacific, derived from the IAP and GOEPR datasets.
Source Data Extended Data Fig. 7
Source data for Extended Data Fig. 7. Processed wind stress curl data (climatology, trend, and significance) are provided in separate sheets within the file.
Source Data Extended Data Fig. 8
Source data for Extended Data Fig. 8. Processed data used in the circulation shift analysis and mapping of the MDT. Each sheet contains clearly labelled data corresponding to specific components of the figure.
Source Data Topography and Land Boundary
Source data for Fig. 3b and Extended Data Fig. 2a. Includes geospatial boundary and topographic datasets used in mapping and analysis.
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Xie, C., Shi, J., Li, D. et al. Southward shift of the Antarctic Circumpolar Current upstream of Drake Passage maintains a stable circumpolar transport. Nat. Clim. Chang. 15, 1324–1332 (2025). https://doi.org/10.1038/s41558-025-02478-9
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DOI: https://doi.org/10.1038/s41558-025-02478-9
