A two-phase response of the Southern Ocean to an increase in greenhouse gas concentrations

• Published in: Geophysical Research Letters
• Main Authors: Goosse, Hugues, Renssen, H.
• Other Authors: UCL - SC/PHYS - Département de physique, UCL - SST/ELI/ELIC - Earth & Climate
• Format: Article in Journal/Newspaper
• Language: English
• Published: Amer Geophysical Union 2001
• Subjects: Southern Ocean; Sea ice
• Online Access: http://hdl.handle.net/2078.1/42508; https://doi.org/10.1029/2001GL013525

The response of the Southern Ocean to an increase in atmospheric greenhouse gas concentrations simulated by a global atmosphere-ocean-sea-ice model can be decomposed in two different phases. Firstly, the ocean damps the surface warming because of its large heat capacity. Secondly, one century after the major increase in greenhouse gases, the warming is amplified because of a positive feedback that is associated with a stronger oceanic meridional heat transport toward the Southern Ocean. Consequently, the long-term decrease in ice area in the Southern Ocean is much larger than in the Northern Hemisphere. This large but delayed response has consequences for the interpretation of both observations and model results.