Impacts of Mean State Ocean Heat Transport on Climate and Its Response to CO <sub>2</sub> Forcing
Abstract Simulations of the slab ocean configuration of the coupled Energy Exascale Earth System Model (E3SM) were used to isolate the role of poleward ocean heat transport (OHT) in shaping the climate and its response to CO 2 forcing. Imposed changes to mean‐state OHT produce compensating changes in atmospheric heat transport (AHT) that are mediated by changes in surface evaporation. A reduction of maximum OHT by 0.56 PW (32%) reduces the global mean surface air temperature by 3.6°C. However, this cooler mean state exhibits 1.2°C more warming under CO 2 quadrupling, with the largest differences occurring at high latitudes. The amplified warming arises from stronger surface albedo and lapse rate feedbacks in polar regions and a shortwave cloud feedback in the southern midlatitudes. These results highlight the critical role of mean‐state OHT in modulating mean‐state climate, the partitioning between the OHT and AHT, and climate sensitivity.
Authors
- Qiuxian Li (ORCID: https://orcid.org/0000-0002-7246-5910)
- Kyle C. Armour (ORCID: https://orcid.org/0000-0002-6833-5179)
- LuAnne Thompson
- Oluwayemi A. Garuba (ORCID: https://orcid.org/0000-0001-7931-7788)
- W. S. Cheng (ORCID: https://orcid.org/0000-0001-9943-4519)
- Jiaxu Zhang (ORCID: https://orcid.org/0000-0002-8564-3026)
- Jian Lu
- Bryce E. Harrop
Institutions
- Pacific Northwest National Laboratory (US)
- Cooperative Institute for Research in Environmental Sciences (US)
- University of Washington (US)
- NOAA Pacific Marine Environmental Laboratory (US)
- Ocean University of China (CN)
Publication Details
- Journal
- Geophysical Research Letters
- Published
- 2026-03-16
- DOI
- https://doi.org/10.1029/2025gl120436
- Primary Topic
- Oceanographic and Atmospheric Processes
- Type
- article
- Field-Weighted Citation Impact
- 0.00