Work

Equatorial Atlantic mid-depth warming indicates Atlantic meridional overturning circulation slowdown

Year: 2025

Type: article

Abstract: Climate models project an Atlantic Meridional Overturning Circulation slowdown under anthropogenic greenhouse warming. Despite a ~1.5 °C increase in the global mean surface temperature, debate remains on whether and when this circulation has slowed. Here we identify a distinctive temperature fingerprint in the equatorial Atlantic that signals the Atlantic Meridional Overturning Circulation change through numerical ocean model experiments. The equatorial Atlantic is a crucial crossroads for the circulation anomalies to propagate to other oceans. A slowdown drives a mid-depth (1000–2000 m) warming in the equatorial Atlantic in a decade via baroclinic Kelvin waves. Analysis of climate models shows that this mid-depth temperature change is a better indicator for Atlantic Meridional Overturning Circulation change on decadal and longer timescales than other surface proxies. Observations reveal a robust mid-depth warming since 1960 that emerged from natural variability in the early 2000s, suggesting a slowdown that already started in the late 20th century.

Source: Communications Earth & Environment

DOI: 10.1038/s43247-025-02793-1

Authors: Qiuping Ren, Shang-Ping Xie, Qihua Peng, Yuanlong Li, Fan Wang

Institutions: Scripps Institution of Oceanography, Chinese Academy of Sciences, University of California San Diego, Institute of Oceanology, Qingdao National Laboratory for Marine Science and Technology

Language: English

Topic: Climate variability and models

Subfield: Global and Planetary Change

Field: Environmental Science

Domain: Physical Sciences

SDGs: Climate action, Life below water

Open Access status: gold

Estimated APC paid: $3,490