- In the deep ocean, density differences drive thermohaline circulation as ocean layers have different temperature & salt content. In the shallower ocean, winds also drive circulation & supply oxygen! Today, areas with little oxygen (Oxygen Minimum Zones-OMZ) form where subsurface circulation is slowNov 4, 2025 14:16
- AMOC slowed 2 times in the last 27k years, and to understand what happens to subsurface circulation with this slowdown, the authors reconstructed oxygen changes using benthic forams distribution in the OMZ off the Senegal coast.
- Findings: with a slow AMOC there was + oxygen, suggesting a stronger subsurface circulation that brought + oxygen to the OMZ🧐Since winds' strength depends on temperature & air pressure, we calculated the sea surface temperature diff. between tropical & NAtlantic: they were larger with a slow AMOC 😱
- In summary, we infer that a weak AMOC-driven heat transport decrease led to a strong temperature gradient between the tropical & NAtlantic, that accelerated subsurface circulation, bringing more oxygen to the OMZ we studied. Did you learn something new? Follow us and share! 🌊🐚🔬🤔
- *In addition, this is happening with intense ocean warming seen in the Atlantic in weak AMOC times. In theory, ocean warming makes oxygen less soluble & should decrease, BUT the results show that circulation is the main oxygen control here! Full study: www.nature.com/articles/s41...
