Attribution of changes in winds over the Southern Ocean from 1950 to 2100

Jarníková, Tereza, Jones, Colin, Rumbold, Steven and Le Quéré, Corinne ORCID: https://orcid.org/0000-0003-2319-0452 (2026) Attribution of changes in winds over the Southern Ocean from 1950 to 2100. Earth System Dynamics, 17 (3). pp. 631-649. ISSN 2190-4979

[thumbnail of esd-17-631-2026]
Preview
PDF (esd-17-631-2026) - Published Version
Available under License Creative Commons Attribution.

Download (11MB) | Preview

Abstract

Strong near-surface westerly winds drive the Southern Ocean circulation and play a key role in setting regional and global climate. In the latter half of the 20th century, depletion of stratospheric ozone over Antarctica has caused these winds to accelerate and move polewards, particularly in austral summer. However, the future evolution of these winds remains uncertain. We use reanalysis data and the UK Earth System Model (UKESM1), with full atmospheric chemistry, to assess the drivers of winds over the recent past and coming century. We first characterize the wind mean state, distribution, and trends over 1980–2019 in the most commonly used atmospheric reanalyses (ERA5, JRA3Q, and MERRA2) to gain insight into observed wind behaviour in the past. We show that while the representation of the mean wind is similar among reanalyses, MERRA2 shows stronger wind acceleration trends that persist year-round, while JRA3Q and ERA5 show weaker acceleration, primarily in austral summer. Using an observational Southern Annular Mode (SAM) index, we show that the weaker, summer-focused trends of JRA3Q and ERA5 are likely more realistic. UKESM1 represents historical trends in winds accurately compared to ERA5 and is within the range of other CMIP6 models for wind and SAM trends over the historical period. Targeted simulations with UKESM1 show ozone depletion is overwhelmingly responsible for the wind acceleration observed in 1980–2020, primarily in austral summer. The effect of ozone depletion on wind speeds peaks in 1980–2000, when it is roughly double that for the entire 40-year period. Ozone recovery is then associated with a slowdown of winds from 2000 to 2050. Beyond 2050, the ozone effect becomes minimal and winds accelerate primarily due to greenhouse gas induced warming, with this trend more evenly distributed across seasons.

Item Type: Article
Additional Information: Data availability: UKESM1 CMIP6 simulations are available through the Earth System Grid Federation (ESGF; https://esgf-index1.ceda.ac.uk/projects/cmip6-ceda/, last access: 1 February 2026) . Additional UKESM1 simulations used in this study are archived at the UK Met Office and available for researchpurposes through the JASMIN platform (https://jasmin.ac.uk/, last access: 1 February 2026) maintained by the Centre for Environmental Data Analysis (CEDA); for details please contact UM_collaboration@metoffice.gov.uk, referencing this paper
Uncontrolled Keywords: general earth and planetary sciences,sdg 12 - responsible consumption and production,sdg 13 - climate action ,/dk/atira/pure/subjectarea/asjc/1900/1900
Faculty \ School: Faculty of Science > School of Environmental Sciences
Faculty of Science > Tyndall Centre for Climate Change Research
University of East Anglia Research Groups/Centres > Faculty of Science > Research Centres > Tyndall Centre for Climate Change Research
University of East Anglia Research Groups/Centres > Theme - ClimateUEA
UEA Research Groups: Faculty of Science > Research Groups > Centre for Ocean and Atmospheric Sciences
Related URLs:
Depositing User: LivePure Connector
Date Deposited: 06 Aug 2026 11:05
Last Modified: 06 Aug 2026 11:05
URI: https://ueaeprints.uea.ac.uk/id/eprint/104012
DOI: 10.5194/esd-17-631-2026

Downloads

Downloads per month over past year

Actions (login required)

View Item View Item