Asymmetric Ocean‐Atmosphere Coupling Between Southeast Pacific and Southern Ocean Cooling Through Circulation and Sea‐Ice Changes

Journal article

Plain Language Summary: Global warming is expected to raise ocean temperatures, yet parts of the Southeast Pacific and the Southern Ocean have cooled over recent decades. These regions, located near the west coast of South America and around Antarctica, are important for regulating Earth's climate and marine ecosystems. Here we analyze observations and reanalysis data from 1960 to 2024 to investigate the physical processes associated with sea surface temperature changes in these two regions. We use a data‐driven approach that accounts for ocean persistence (“memory”) and quantifies the additional contribution of atmospheric circulation, clouds, and sea ice. We find that cooling in the two regions arises from different local processes. In the Southern Ocean, changes in sea ice and large‐scale atmospheric circulation help explain much of the recent cooling. In the Southeast Pacific, cooling is mainly linked to changes in winds, clouds, and surface heat exchange. Importantly, we also find that the connection between the two regions is uneven. Over recent decades, variability in the Southern Ocean has increasingly influenced temperatures in the Southeast Pacific, while the reverse influence has weakened. These results highlight how long‐distance links between high‐latitude and subtropical processes can shape regional ocean temperature trends under climate change.

Authors: Hu, X; Slater, LJ; Kang, SM; Castle, JL

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Wiley
• Journal: Geophysical Research Letters
• Volume: 53
• Issue: 12
• Article number: e2026GL122210
• Publication date: 2026-06-20
• Acceptance date: 2026-05-27
• DOI: 10.1029/2026gl122210
• EISSN: 1944-8007
• ISSN: 0094-8276
• Language: English
• Keywords: teleconnection; sea surface temperature cooling; interpretable machine learning; air‐sea interation