Home / Science / Antarctic Deep Water Flow Shrinks Dramatically
Antarctic Deep Water Flow Shrinks Dramatically
17 Jul
Summary
- Antarctic Bottom Water volume decreased by 2.94% since 2002.
- Decline accelerated sharply after 2015, now four times faster.
- Reduced sea ice formation is linked to weaker bottom water production.
Monitoring Antarctic Bottom Water (AABW) for over two decades has revealed a significant decline in its volume, impacting global ocean circulation. Researchers observed a steady decrease in AABW from 2002 to 2023, with the rate of decline accelerating sharply after 2015.
Analysis using the SatGEM-2 dataset indicated that by 2023, AABW volume had reduced by 2.94% from its 2002 baseline. This trend has been linked to major changes in Antarctic sea ice, as salt exclusion during sea ice formation normally enriches surrounding water, making it denser and contributing to AABW.
Concerns are growing as less dense deep-ocean water may reduce the transport of vital oxygen and heat into the ocean depths. The Southern Ocean, a key absorber of excess heat and carbon, could be affected by these changes.
Impacts of reduced AABW formation, particularly in the Atlantic sector of the Southern Ocean, could influence climates in regions like the UK. While immediate weather changes are not implied, ongoing observations are crucial to determine if this slowdown is a temporary fluctuation or a long-term climate response.
