Neodymium isotopes as a paleo-water mass tracer: A model-data reassessment

• DOI: 10.1016/j.quascirev.2022.107404
• Publication Date: 2022-02-03T06:10:26Z
• Authors: Frerk Pöppelmeier; Jörg Lippold; Patrick Blaser; Marcus Gutjahr; Martin Frank; Thomas F. Stocker
• Keywords: Biogeochemical Cycle; Last Glacial Maximum; paleoceanography; Deglaciation; Radiogenic nuclide

Proxy reconstructions from deep ocean sediments have helped to shape our understanding of the role global overturning circulation in past climate change. Neodymium (Nd) isotopes contributed this knowledge, as a tracer bottom water provenance and mixing. Here, we extend implementation Nd physical-biogeochemical Bern3D model by revising number critical parameterizations, which result an improved description marine cycle. We exploit dynamically consistent framework model, allows us assess processes driving non-conservative isotope behavior with particular focus on Last Glacial Maximum (LGM) its substantially different climatic, oceanic, biogeochemical boundary conditions. show that more radiogenic isotopic compositions found throughout glacial can be explained changes weathering input fluxes do not require large reorganizations circulation. Our findings further highlight composition mass only significantly affected benthic flux, but also modified vertical downward transport via reversible scavenging. While these limited impact modern ocean, they were pronounced during LGM mostly independent state, their contributions being non-linear, partially opposing, spatially variable. During transiently simulated deglaciation variations induced major weakenings resumptions are most South Atlantic, while increasingly muted towards north. Hence, it emerges interpretation authigenic records requires specific considerations order reliably infer basin-scale mixing past.