Year: 2025
Type: article
Abstract: The Southern Ocean Meridional Overturning Circulation (MOC) has intensified in recent decades, yet the interplay between its Eulerian and eddy components under future warming remains uncertain. Using ensemble climate simulations, here we show that the Eulerian-mean MOC shifts poleward under high-emission scenarios during the twenty-first century, with compensating eddy-induced MOC sustaining a uniformly intensified residual overturning. This response is less pronounced under low-emission scenarios with climate mitigation. Likewise, a poleward-shifted Eulerian-mean MOC occurred during the Mid-Pliocene Warm Period, but with weaker, broader eddy compensation, leading to non-uniform intensified residual overturning. Across past and future warming climates, the eddy-induced MOC is primarily modulated by surface heat flux changes at lower latitudes and by freshwater flux changes at higher latitudes over the Southern Ocean. The buoyancy forcing changes drive northward Antarctic upwelling, promoting Antarctic bottom water formation. Along with MOC changes, ventilation intensifies in the lower latitudes of the Southern Ocean as related to the subduction branch, especially during the past warm period.
Source: Nature Communications
Authors: Tingting Zhu, Wei Liu
Institution: University of California, Riverside
Language: English
Subfield: Oceanography
Field: Earth and Planetary Sciences
Domain: Physical Sciences
SDG: Climate action
Open Access status: gold
Estimated APC paid: $6,990
Funder: National Science Foundation
Awards: Understanding Southern Ocean heat uptake and redistribution in a warming climate, Collaborative research: Quantifying Global and Regional Impacts of the Atlantic Meridional Overturning Circulation (AMOC) Slowdown in the 21st (twenty-first) Century, CAREER: Unraveling the Role of the Varying Ocean Circulation in Climate Change
OpenAlex ID: W4416668008