Robustness and Mechanisms of the Atmospheric Response Over the Southern Ocean to Idealized Freshwater Input Around Antarctica
Abstract Enhanced Antarctic ice sheet mass loss yields ocean surface freshening, cooling and sea ice expansion, which result in changes in the atmospheric conditions. Using the Southern Ocean Freshwater Input from Antarctica (SOFIA) multi‐model ensemble, we study the atmospheric response to a 100‐year idealized freshwater release of 0.1 Sv. All models simulate a surface‐intensified tropospheric cooling and lower‐stratospheric warming south of 35°S. Tropospheric cooling is attributed to sea ice expansion and the associated albedo enhancement in winter and a colder sea surface in summer. This cooling yields a downward displacement of the tropopause, reduced stratospheric water vapor content and ultimately warming around 200 hPa. An enhanced southward eddy heat flux explains warming at 10–100 hPa during austral winter. Despite a temporally (and spatially) uniform prescribed freshwater flux, a prominent sea ice seasonal cycle and atmosphere dynamics result in a distinct seasonal pattern in the occurrence and magnitude of the temperature responses.
Authors
- Sabine Bischof (ORCID: https://orcid.org/0000-0002-7035-5224)
- Inga Jane Smith (ORCID: https://orcid.org/0000-0002-0653-8296)
- Wenjuan Huo (ORCID: https://orcid.org/0000-0001-9807-4726)
- Ariaan Purich (ORCID: https://orcid.org/0000-0003-2248-5937)
- Morven Muilwijk (ORCID: https://orcid.org/0000-0001-9101-6646)
- Andrew George Pauling (ORCID: https://orcid.org/0000-0003-4545-0809)
- Rebecca L. Beadling (ORCID: https://orcid.org/0000-0001-9491-8776)
- Torge Martin (ORCID: https://orcid.org/0000-0002-0882-8780)
- Tore Hattermann (ORCID: https://orcid.org/0000-0002-5538-2267)
- Jiping Liu
- Neil C. Swart (ORCID: https://orcid.org/0000-0002-8200-6187)
- John Marshall (ORCID: https://orcid.org/0000-0001-9230-3591)
- Max Thomas (ORCID: https://orcid.org/0000-0002-2327-3664)
- Qian Li (ORCID: https://orcid.org/0000-0002-2099-233X)
- Xiaoqi Xu (ORCID: https://orcid.org/0000-0001-7492-9160)
Institutions
- Goddard Institute for Space Studies (US)
- Met Office (GB)
- Environment and Climate Change Canada (CA)
- Sun Yat-sen University (CN)
- Chinese Academy of Sciences (CN)
- GEOMAR Helmholtz Centre for Ocean Research Kiel (DE)
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou) (CN)
- Institute of Atmospheric Physics (CN)
- University of Chinese Academy of Sciences (CN)
- Monash University (AU)
- Massachusetts Institute of Technology (US)
- University of Otago (NZ)
- Temple University (US)
- Norwegian Polar Institute (NO)
Publication Details
- Journal
- Geophysical Research Letters
- Published
- 2025-05-22
- DOI
- https://doi.org/10.1029/2024gl113734
- Citations
- 3
- Primary Topic
- Atmospheric and Environmental Gas Dynamics
- Type
- article
- Field-Weighted Citation Impact
- 3.32
Funders
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou)
- National Key Research and Development Program of China