Seawater carbonate chemistry, processes and elements during experiments with planktonic foraminifera Orbulina universa, 2004


We investigate the sensitivity of U/Ca, Mg/Ca, and Sr/Ca to changes in seawater [CO3[2-]] and temperature in calcite produced by the two planktonic foraminifera species, Orbulina universa and Globigerina bulloides, in laboratory culture experiments. Our results demonstrate that at constant temperature, U/Ca in O. universa decreases by 25 +/- 7% per 100 µmol [CO3[2-]] kg-1, as seawater [CO3[2-]] increases from 110 to 470 µmol kg-1. Results from G. bulloides suggest a similar relationship, but U/Ca is consistently offset by ~+40% at the same environmental [CO3[2-]]. In O. universa, U/Ca is insensitive to temperature between 15°C and 25°C. Applying the O. universa relationship to three U/Ca records from a related species, Globigerinoides sacculifer, we estimate that Caribbean and tropical Atlantic [CO3[2-]] was 110 +/- 70 µmol kg-1 and 80 +/- 40 µmol kg-1 higher, respectively, during the last glacial period relative to the Holocene. This result is consistent with estimates of the glacial-interglacial change in surface water [CO3[2-]] based on both modeling and on boron isotope pH estimates. In settings where the addition of U by diagenetic processes is not a factor, down-core records of foraminiferal U/Ca have potential to provide information about changes in the ocean's carbonate concentration.

In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Lavigne and Gattuso, 2011) was used to compute a complete and consistent set of carbonate system variables, as described by Nisumaa et al. (2010). In this dataset the original values were archived in addition with the recalculated parameters (see related PI).

Supplement to: Russell, Ann D; Hönish, Bärbel; Spero, Howard J; Lea, David W (2004): Effects of seawater carbonate ion concentration and temperature on shell U, Mg, and Sr in cultured planktonic foraminifera. Geochimica et Cosmochimica Acta, 68(21), 4347-4361

Related Identifier
Metadata Access
Creator Russell, Ann D ORCID logo; Hönish, Bärbel; Spero, Howard J ORCID logo; Lea, David W
Publisher PANGAEA
Contributor Nisumaa, Anne-Marin
Publication Year 2004
Funding Reference Seventh Framework Programme Crossref Funder ID 211384 European Project on Ocean Acidification; Sixth Framework Programme Crossref Funder ID 511106 European network of excellence for Ocean Ecosystems Analysis
Rights Creative Commons Attribution 3.0 Unported;
OpenAccess true
Resource Type Supplementary Dataset; Dataset
Format text/tab-separated-values
Size 1631 data points
Discipline Earth System Research