A proxy modelling approach to assess the potential of extracting ENSO signal from tropical Pacific planktonic foraminifera

• Published in: Climate of the Past
• Main Authors: Metcalfe, Brett, Lougheed, Bryan C., Waelbroeck, Claire, Roche, Didier
• Other Authors: Cluster Earth and Climate Amsterdam, Department of Earth Sciences Amsterdam, VU University Amsterdam-VU University Amsterdam, Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Department of Earth Sciences Uppsala, Uppsala University, Paléocéanographie (PALEOCEAN), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), ANR-10-LABX-0018,L-IPSL,LabEx Institut Pierre Simon Laplace (IPSL): Understand climate and anticipate future changes(2010), European Project: 339108,EC:FP7:ERC,ERC-2013-ADG,ACCLIMATE(2014)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; Pacific; Planktonic foraminifera
• Online Access: https://hal.archives-ouvertes.fr/hal-02766071; https://hal.archives-ouvertes.fr/hal-02766071/document; https://hal.archives-ouvertes.fr/hal-02766071/file/cp-16-885-2020.pdf; https://doi.org/10.5194/cp-16-885-2020

International audience A complete understanding of past El Niño-Southern Oscillation (ENSO) fluctuations is important for the future predictions of regional climate using climate models. One approach to reconstructing past ENSO dynamics uses planktonic foraminifera as recorders of past climate to assess past spatio-temporal changes in upper ocean conditions. In this paper, we utilise a model of planktonic foraminifera populations, Foraminifera as Modelled Entities (FAME), to forward model the potential monthly average δ 18 O c and temperature signal proxy values for Globigeri-noides ruber, Globigerinoides sacculifer, and Neoglobo-quadrina dutertrei from input variables covering the period of the instrumental record. We test whether the modelled foraminifera population δ 18 O c and T c associated with El Niño events statistically differ from the values associated with other climate states. Provided the assumptions of the model are correct, our results indicate that the values of El Niño events can be differentiated from other climate states using these species. Our model computes the proxy values of foraminifera in the water, suggesting that, in theory, water locations for a large portion of the tropical Pacific should be suitable for differentiating El Niño events from other climate states. However, in practice it may not be possible to differentiate climate states in the sediment record. Specifically, comparison of our model results with the sedimentological features of the Pacific Ocean shows that a large portion of the hydrographically/ecologically suitable water regions coincide with low sediment accumulation rate at the sea floor and/or of sea floor that lie below threshold water depths for calcite preservation.