FN Archimer Export Format
PT J
TI Mg∕Ca, Sr∕Ca and stable isotopes from the planktonic foraminifera T. sacculifer: testing a multi-proxy approach for inferring paleotemperature and paleosalinity
BT 
AF Dissard, Delphine
   Reichart, Gert Jan
   Menkes, Christophe
   Mangeas, Morgan
   Frickenhaus, Stephan
   Bijma, Jelle
AS 1:1,2;2:3,4;3:5;4:5;5:2;6:2;
FF 1:;2:;3:;4:;5:;6:;
C1 UMR LOCEAN (IRD-CNRS-MNHN-Sorbonne Université), Centre IRD de Nouméa, 101 Promenade Roger Laroque, Noumea 98848, New Caledonia
   Alfred-Wegener-Institute, Helmholtz-Zentrum für Polar- und Meeresforschung, Am Handelshafen 12, 27570 Bremerhaven, Germany
   Royal Netherlands Institute for Sea Research (NIOZ), Den Burg, Texel, the Netherlands
   Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, the Netherlands
   UMR ENTROPIE (IRD, Université de la Réunion, CNRS, IFREMER, UNC), Centre IRD de Nouméa, 101 Promenade Roger Laroque, Noumea 98848, New Caledonia
C2 IRD, FRANCE
   INST A WEGENER, GERMANY
   INST SEA RESEARCH (NIOZ), NETHERLANDS
   UNIV UTRECHT, NETHERLANDS
   IRD, FRANCE
UM ENTROPIE
IN WOS Cotutelle UMR
   DOAJ
   copubli-france
   copubli-europe
IF 5.092
TC 4
UR https://archimer.ifremer.fr/doc/00677/78884/81200.pdf
   https://archimer.ifremer.fr/doc/00677/78884/81201.pdf
LA English
DT Article
AB Over the last decades, sea surface temperature (SST) reconstructions based on the Mg∕Ca of foraminiferal calcite have frequently been used in combination with the δ18O signal from the same material to provide estimates of the δ18O of water (δ18Ow), a proxy for global ice volume and sea surface salinity (SSS). However, because of error propagation from one step to the next, better calibrations are required to increase the accuracy and robustness of existing isotope and element to temperature proxy relationships. Towards that goal, we determined Mg∕Ca, Sr∕Ca and the oxygen isotopic composition of Trilobatus sacculifer (previously referenced as Globigerinoides sacculifer) collected from surface waters (0–10 m) along a north–south transect in the eastern basin of the tropical and subtropical Atlantic Ocean. We established a new paleotemperature calibration based on Mg∕Ca and on the combination of Mg∕Ca and Sr∕Ca. Subsequently, a sensitivity analysis was performed in which one, two or three different equations were considered. Results indicate that foraminiferal Mg∕Ca allows for an accurate reconstruction of surface water temperature. Combining equations, δ18Ow can be reconstructed with a precision of about ± 0.5 ‰. However, the best possible salinity reconstruction based on locally calibrated equations only allowed for a reconstruction with an uncertainty of ± 2.49. This was confirmed by a Monte Carlo simulation, applied to test successive reconstructions in an “ideal case” in which explanatory variables are known. This simulation shows that from a purely statistical point of view, successive reconstructions involving Mg∕Ca and δ18Oc preclude salinity reconstructions with a precision better than ± 1.69 and hardly better than ± 2.65 due to error propagation. Nevertheless, a direct linear fit to reconstruct salinity based on the same measured variables (Mg∕Ca and δ18Oc) was established. This direct reconstruction of salinity led to a much better estimation of salinity (± 0.26) than the successive reconstructions. 
PY 2021
PD JAN
SO Biogeosciences
SN 1726-4170
PU Copernicus GmbH
VL 18
IS 2
UT 000611534700002
BP 423
EP 439
DI 10.5194/bg-18-423-2021
ID 78884
ER

EF