“Bayesian calibration of the Mg/Ca paleothermometer in planktic foraminifera” Jessica E. Tierney1, Steven B. Malevich1, William Gray2, Lael Vetter1 & Kaustubh Thirumalai1 1University of Arizona, Department of Geosciences, 1040 4th St. Tucson, AZ 85721. 2Laboratoire des Sciences du Climat et de l’Environnement (LSCE/IPSL), Gif-sur-Yvette, France This is a post print of a paper published in the journal Paleoceanography and Paleoclimatology, doi: 10.1029/2019PA003744 https://doi.org/10.1029/2019PA003744 manuscript submitted to Paleoceanography and Paleoclimatology 1 Bayesian calibration of the Mg/Ca paleothermometer 2 in planktic foraminifera 1 1 2 1 3 Jessica E. Tierney , Steven B. Malevich , William Gray , Lael Vetter & 1 4 Kaustubh Thirumalai 1 5 University of Arizona Department of Geosciences, 1040 E 4th St Tucson AZ 85721 2 6 Laboratoire des Sciences du Climat et de l’Environnement (LSCE/IPSL), Gif-sur-Yvette, France 7 Key Points: 8 • We introduce Mg/Ca Bayesian calibrations for planktic foraminifera 9 • Hierarchical modeling is used to constrain multivariate Mg/Ca sensitivities 10 • For deep-time applications, we incorporate estimates of Mg/Ca of seawater Corresponding author: Jessica Tierney,
[email protected] –1– manuscript submitted to Paleoceanography and Paleoclimatology 11 Abstract 12 The Mg/Ca ratio of planktic foraminifera is a widely-used proxy for sea-surface temper- 13 ature, but is also sensitive to other environmental factors. Previous work has relied on 14 correcting Mg/Ca for non-thermal influences. Here, we develop a set of Bayesian mod- 15 els for Mg/Ca in four major planktic groups – Globigerinoides ruber (including both pink 16 and white chromotypes), Trilobatus sacculifer, Globigerina bulloides, and Neogloboquad- 17 rina pachyderma (including N.