Climatic modulation of surface acidification rates through summertime wind forcing in the Southern Ocean.
Where this comes from
- Record sourced from PubMed, PMID 30104675.
- Also identified by DOI 10.1038/s41467-018-05443-7 and PMC identifier 6089918.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
While the effects of the Southern Annular Mode (SAM), a dominant climate variability mode in the Southern Ocean, on ocean acidification have been examined using models, no consensus has been reached. Using observational data from south of Tasmania, we show that during a period with positive SAM trends, surface water pH and aragonite saturation state at 60°-55° S (Antarctic Zone) decrease in austral summer at rates faster than those predicted from atmospheric CO<sub>2</sub> increase alone, whereas an opposite pattern is observed at 50°-45° S (Subantarctic Zone). Together with other processes, the enhanced acidification at 60°-55° S may be attributed to increased westerly winds that bring in more "acidified" waters from the higher latitudes via enhanced meridional Ekman transport and from the subsurface via increased vertical mixing. Our observations support climatic modulation of ocean acidification superimposed on the effect of increasing atmospheric CO<sub>2</sub>.