Session: Benchmarking & cross-cutting Group 1 (Isotope modelling, COMPARE)
Author: Jennifer Dentith / email@example.com / University of Leeds
Co-author: Ruza Ivanovic, University of Leeds;
Lauren Gregoire, University of Leeds;
Julia Tindall, University of Leeds;
Laura F. Robinson, University of Bristol;
Changes in the strength and structure of the Atlantic Meridional Overturning Circulation (MOC) may have played a key role in abrupt palaeoclimatic transitions and could result in significant climatic impacts in the future. Carbon isotopes can be used to infer palaeoceanographic circulation changes. However, discrepancies exist in the interpretation of isotopes in geological archives. By directly simulating isotopic tracer fields within complex numerical models, modelled tracer concentrations can be compared to observations rather than the more uncertain climatic interpretations. We simulate the radioactive isotope 14C in the ocean component of the FAMOUS General Circulation Model to study large-scale ocean circulation, the oceanic carbon cycle and air-sea gas exchange. This abiotic tracer implementation accounts for the effects of air-sea gas exchange, advection and radioactive decay. The model was spun-up for 10,000 years to allow 14C concentrations in the deep ocean to equilibrate and evaluated by comparing simulated bomb 14C distributions with observational estimates. Here, we use the isotope-enabled model to investigate the surface climatologies and 14C fingerprint of different MOC stability regimes, as identified by net freshwater import into the Atlantic (Fov). Overall, we aim to improve our understanding of palaeoceanographic circulation at the Last Glacial Maximum and during the deglaciation.