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Other research product . 2019

The potential of 230Th for detection of ocean acidification impacts on pelagic carbonate production

Heinze, Christoph; Ilyina, Tatiana; Gehlen, Marion;
Open Access
English
Published: 31 Jan 2019
Abstract

Concentrations of dissolved 230Th in the ocean water column increase with depth due to scavenging and downward particle flux. Due to the 230Th scavenging process, any change in the calcium carbonate (CaCO3) fraction of the marine particle flux due to changes in biological CaCO3 hard-shell production as a consequence of progressing ocean acidification would be reflected in the dissolved 230Th activity. Our prognostic simulations with a biogeochemical ocean general circulation model using different scenarios for the reduction of CaCO3 production under ocean acidification and different greenhouse gas emission scenarios – the Representative Concentration Pathways (RCPs) 8.5 to 2.6 – reveal the potential for deep 230Th measurements to detect reduced CaCO3 production at the sea surface. The time of emergence of an acidification-induced signal on dissolved 230Th is of the same order of magnitude as for alkalinity measurements. Interannual and decadal variability in factors other than a reduction in CaCO3 hard-shell production may mask the ocean-acidification-induced signal in dissolved 230Th and make detection of the pure CaCO3-induced signal more difficult so that only really strong changes in marine CaCO3 export would be unambiguously identifiable soon. Nevertheless, the impacts of changes in CaCO3 export production on marine 230Th are stronger than those for changes in POC (particulate organic carbon) or clay fluxes.

Subjects by Vocabulary

ACM Computing Classification System: TheoryofComputation_MATHEMATICALLOGICANDFORMALLANGUAGES

60 references, page 1 of 6

Anderson, R. F., Bacon, M. P., and Brewer, P. G.: Removal of 230Th and 231Pa at Ocean Margins, Earth Planet. Sc. Lett., 66, 73-90, 1983.

Anderson, R. F., Fleisher, M. Q., Robinson, L. F., Edwards, R. L., Hoff, J. A., Moran, S. B., van der Loeff, M. R., Thomas, A. L., Roy-Barman, M., and Francois, R.: GEOTRACES intercalibration of 230Th, 232Th, 231Pa, and prospects for 10Be, Limnol. Oceanogr.-Meth., 10, 179-213, 2012.

Bacon, M. P. and Anderson, R. F.: Distribution of Thorium Isotopes between Dissolved and Particulate Forms in the Deep-Sea, J. Geophys. Res.-Oceans, 87, 2045-2056, 1982.

Bacon, M. P., Huh, C. A., and Moore, R. M.: Vertical Profiles of Some Natural Radionuclides over the Alpha-Ridge, Arctic Ocean, Earth Planet. Sc. Lett., 95, 15-22, 1989.

Bates, N. R.: Interannual variability of the oceanic CO2 sink in the subtropical gyre of the North Atlantic Ocean over the last 2 decades, J. Geophys. Res.-Oceans, 112, C09013, https://doi.org/10.1029/2006JC003759, 2007.

Bopp, L., Resplandy, L., Orr, J. C., Doney, S. C., Dunne, J. P., Gehlen, M., Halloran, P., Heinze, C., Ilyina, T., Séférian, R., Tjiputra, J., and Vichi, M.: Multiple stressors of ocean ecosystems in the 21st century: projections with CMIP5 models, Biogeosciences, 10, 6225-6245, https://doi.org/10.5194/bg-10- 6225-2013, 2013.

Boudreau, B. P.: Diagenetic models and their implementation - modelling transport and reactions in aquatic systems, Springer, Heidelberg, 1997.

Carter, B. R., Frolicher, T. L., Dunne, J. P., Rodgers, K. B., Slater, R. D., and Sarmiento, J. L.: When can ocean acidification impacts be detected from decadal alkalinity measurements?, Global Biogeochem. Cy., 30, 595-612, 2016. [OpenAIRE]

Chase, Z., Anderson, R. F., Fleisher, M. Q., and Kubik, P. W.: The influence of particle composition and particle flux on scavenging of Th, Pa and Be in the ocean, Earth Planet. Sc. Lett., 204, 215- 229, 2002.

Chase, Z., Anderson, R. F., Fleisher, M. Q., and Kubik, P. W.: Scavenging of 230Th, 231Pa and 10Be in the Southern Ocean (SW Pacific sector): the importance of particle flux, particle composition and advection, Deep-Sea Res. Pt. II, 50, 739-768, 2003.

Funded by
EC| EPOCA
Project
EPOCA
European Project on Ocean Acidification
  • Funder: European Commission (EC)
  • Project Code: 211384
  • Funding stream: FP7 | SP1 | ENV
,
EC| CARBOCHANGE
Project
CARBOCHANGE
Changes in carbon uptake and emissions by oceans in a changing climate
  • Funder: European Commission (EC)
  • Project Code: 264879
  • Funding stream: FP7 | SP1 | ENV
Related to Research communities
European Marine Science Marine Environmental Science : European project on ocean acidification
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