Ocean Acidification trends and Carbonate System dynamics in the North Atlantic Subpolar Gyre during 2009–2019
The CO 2 -carbonate system dynamics in the North Atlantic Subpolar Gyre (NASPG) were evaluated between 2009 and 2019. Data was collected aboard eight summer cruises through the CLIVAR 59.5º N section. The Ocean Acidification (OA) patterns and the reduction in the saturation state of calcite...
Main Authors: | , , , , , , , , |
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Format: | Text |
Language: | English |
Published: |
2024
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Subjects: | |
Online Access: | https://doi.org/10.5194/egusphere-2024-1388 https://egusphere.copernicus.org/preprints/2024/egusphere-2024-1388/ |
Summary: | The CO 2 -carbonate system dynamics in the North Atlantic Subpolar Gyre (NASPG) were evaluated between 2009 and 2019. Data was collected aboard eight summer cruises through the CLIVAR 59.5º N section. The Ocean Acidification (OA) patterns and the reduction in the saturation state of calcite ( Ω Ca ) and aragonite ( Ω Arag ) in response to the increasing anthropogenic CO 2 ( C ant ) were assessed within the Irminger, Iceland and Rockall basins during a poorly-assessed decade in which the physical patterns reversed in comparison with previous well-known periods. The observed cooling, freshening and enhanced ventilation increased the interannual rate of accumulation of C ant in the interior ocean by 50–86 % and the OA rates by close to 10 %. The OA trends were 0.0013–0.0032 units yr -1 in the Irminger and Iceland basin and 0.0006–0.0024 units yr -1 in the Rockall Trough, causing a decline in Ω Ca and Ω Arag of 0.004–0.021 and 0.003–0.0013 units yr -1 , respectively. The C ant -driven rise in total inorganic carbon ( C T ) was the main driver of the OA (contributed by 53–68 % in upper layers and >82 % toward the interior ocean) and the reduction in Ω Ca and Ω Arag (>64 %). The transient decrease in temperature, salinity and A T collectively counteracts the C T -driven acidification by 45–85 % in the upper layers and in the shallow Rockall Trough and by <10 % in the interior ocean. The present investigation reports the acceleration of the OA within the NASPG and expands knowledge about the future state of the ocean. |
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