2:00 PM - 2:15 PM
[ACG39-14] Spreading of aragonite undersaturated water in the Canada Basin of the Arctic Ocean
In the Canada Basin of the Arctic Ocean, aragonite undersaturation has been observed in the surface and subsurface layers. Ocean acidification and freshening cause surface undersaturation, while the advection of acidified Pacific-origin water causes subsurface undersaturation. In this study, we investigate the vertical distribution of aragonite saturation state in the Canada Basin from 2003 to 2019, estimate the change in thickness and volume of undersaturated water, and discuss the contributing factors.
The thickness of unsaturated water increased significantly in both the surface and subsurface layers. The volume of unsaturated water increased 11-fold in the surface layer and 1.5-fold in the subsurface layer from 2003 to 2019. Our analysis shows that the increase in the surface layer was mainly caused by freshening in the mid-2000s, but by ocean acidification after 2016. In the subsurface layer, ocean acidification accounts for 76% of the volume increase, and the expansion of Pacific-origin water explains the remaining 24%. These results indicate that the volume of aragonite unsaturated water in the Canada Basin has increased significantly, and ocean acidification is a major factor.
The thickness of unsaturated water increased significantly in both the surface and subsurface layers. The volume of unsaturated water increased 11-fold in the surface layer and 1.5-fold in the subsurface layer from 2003 to 2019. Our analysis shows that the increase in the surface layer was mainly caused by freshening in the mid-2000s, but by ocean acidification after 2016. In the subsurface layer, ocean acidification accounts for 76% of the volume increase, and the expansion of Pacific-origin water explains the remaining 24%. These results indicate that the volume of aragonite unsaturated water in the Canada Basin has increased significantly, and ocean acidification is a major factor.