Journal cover Journal topic
Biogeosciences An interactive open-access journal of the European Geosciences Union
Biogeosciences, 4, 205-213, 2007
© Author(s) 2007. This work is licensed under
the Creative Commons Attribution-NonCommercial-ShareAlike 2.5 License.
20 Mar 2007
Dissolution of calcium carbonate: observations and model results in the subpolar North Atlantic
K. Friis1,*, R. G. Najjar1, M. J. Follows2, S. Dutkiewicz2, A. Körtzinger3, and K. M. Johnson3 1Pennsylvania State University, Department of Meteorology, 503 Walker Building, University Park, PA 16802-5013, USA
2Massachusetts Institute of Technology, Department of Earth, Atmosphere and Planetary Sciences, 77 Massachusetts Av., Cambridge, MA 02139, USA
3Leibniz-Institut für Meereswissenschaften an der Universität Kiel, Marine Biogeochemistry, Düsternbrooker Weg 20, 24105 Kiel, Germany
*now at: Dechema e.V., Theodor-Heuss-Allee 25, 60486 Frankfurt am Main, Germany
Abstract. We investigate the significance of in situ dissolution of calcium carbonate above its saturation horizons using observations from the open subpolar North Atlantic [sNA] and to a lesser extent a 3-D biogeochemical model. The sNA is particularly well suited for observation-based detections of in situ, i.e. shallow-depth CaCO3 dissolution [SDCCD] as it is a region of high CaCO3 production, deep CaCO3 saturation horizons, and precisely-defined pre-formed alkalinity. Based on the analysis of a comprehensive alkalinity data set we find that SDCCD does not appear to be a significant process in the open sNA. The results from the model support the observational findings by indicating that there is not a significant need of SDCCD to explain observed patterns of alkalinity in the North Atlantic. Instead our investigation points to the importance of mixing processes for the redistribution of alkalinity from dissolution of CaCO3 from below its saturation horizons. However, mixing has recently been neglected for a number of studies that called for SDCCD in the sNA and on global scale.

Citation: Friis, K., Najjar, R. G., Follows, M. J., Dutkiewicz, S., Körtzinger, A., and Johnson, K. M.: Dissolution of calcium carbonate: observations and model results in the subpolar North Atlantic, Biogeosciences, 4, 205-213,, 2007.
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