Calcium carbonate dissolution in the upper 1000 m of the eastern North Atlantic. Issue 4 (4th April 2014)

• Record Type: Journal Article
• Authors: Barrett, Pamela M.; Resing, Joseph A.; Buck, Nathaniel J.; Feely, Richard A.; Bullister, John L.; Buck, Clifton S.; Landing, William M.
• Is Part Of: Global biogeochemical cycles. Volume 28:Issue 4(2014:Apr.)
• Page Start: 386
• Page End: 397
• Publication Date: 2014-04-04
• Subjects: Biogeochemical cycles -- Periodicals; Electronic journals; 577.1405
• DOI: 10.1002/2013GB004619
• Languages: English
• ISSNs: 0886-6236

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <p>Recent analyses suggest that considerable CaCO<sub>3</sub> dissolution may occur in the upper water column of the ocean (< 1500 m). This study uses the distribution of particulate calcium from high‐resolution suspended matter sampling along the Climate Variability and Predictability/CO<sub>2</sub> Repeat Hydrography A16N transect in 2003 to estimate CaCO<sub>3</sub> dissolution in the top 1000 m of the North Atlantic. Dissolution rates were also approximated using changes in total alkalinity measurements along isopycnal surfaces. Water masses were found to be undersaturated with respect to aragonite at intermediate depths (400–1000 m) in the eastern tropical North Atlantic. The CaCO<sub>3</sub> dissolution rate in this region is estimated to be 0.9 mmol CaCO<sub>3</sub> m<sup>−2</sup> d<sup>−1</sup>, indicating this region is a hotspot for upper water column CaCO<sub>3</sub> dissolution compared to the Atlantic basin as a whole. Dissolution rates calculated from particulate calcium distributions outside of this region were significantly lower (0.2 mmol CaCO<sub>3</sub> m<sup>−2</sup> d<sup>−1</sup>) and are comparable to previous estimates of CaCO<sub>3</sub> dissolution flux for the Atlantic Ocean. The magnitude of upper water column dissolution rates compared to measured surface ocean CaCO<sub>3</sub> standing stocks suggests that biologically mediated CaCO<sub>3</sub> dissolution may be occurring in the top 1000 m of the Atlantic.</p> </abstract>