A Last Glacial Maximum world-ocean simulation at eddy-permitting resolution – Part 1: Experimental design and basic evaluation
2013 (English)In: Climate of the Past Discussions, ISSN 1814-9340, E-ISSN 1814-9359, Vol. 9, 297-328 p.Article in journal (Refereed) Published
Most state-of-the-art climate models include a coarsely resolved oceanic compo- nent, which has difficulties in capturing detailed dynamics, and therefore eddy- permitting/eddy-resolving simulations have been developed to reproduce the observed World Ocean. In this study, an eddy-permitting numerical experiment is conducted to simulate the global ocean state for a period of the Last Glacial Maximum (LGM, ∼26500 to 19000yr ago) and to investigate the improvements due to taking into account these higher spatial scales. The ocean general circulation model is forced by a 49-yr sample of LGM atmospheric fields constructed from a quasi-equilibrated climate-model simulation. The initial state and the bottom boundary condition conform to the Paleoclimate Modelling Intercomparison Project (PMIP) recommendations. Be- fore evaluating the model efficiency in representing the paleo-proxy reconstruction of the surface state, the LGM experiment is in this first part of the investigation, compared with a present-day eddy-permitting hindcast simulation as well as with the available PMIP results. It is shown that the LGM eddy-permitting simulation is consistent with the quasi-equilibrated climate-model simulation, but large discrepancies are found with the PMIP model analyses, probably due to the different equilibration states. The strongest meridional gradients of the sea-surface temperature are located near 40° N and S, this due to particularly large North-Atlantic and Southern-Ocean sea-ice covers. These also modify the locations of the convection sites (where deep-water forms) and most of the LGM Conveyor Belt circulation consequently takes place in a thinner layer than today. Despite some discrepancies with other LGM simulations, a glacial state is captured and the eddy-permitting simulation undertaken here yielded a useful set of data for comparisons with paleo-proxy reconstructions.
Place, publisher, year, edition, pages
2013. Vol. 9, 297-328 p.
Oceanography, Hydrology, Water Resources
Research subject Atmospheric Sciences and Oceanography
IdentifiersURN: urn:nbn:se:su:diva-88440DOI: 10.5194/cpd-9-297-2013OAI: oai:DiVA.org:su-88440DiVA: diva2:611224