Magnitude of the 8.2 ka event freshwater forcing based on stable isotope modelling and comparison to future Greenland melting

Abstract The northern hemisphere experienced an abrupt cold event ~ 8200 years ago (the 8.2 ka event) that was triggered by the release of meltwater into the Labrador Sea, and resulting in a weakening of the poleward oceanic heat transport. Although this event has been considered a possible analogue...

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Bibliographic Details
Published in:Scientific Reports
Main Authors: Aguiar, Wilton, Meissner, Katrin J., Montenegro, Alvaro, Prado, Luciana, Wainer, Ilana, Carlson, Anders E., Mata, Mauricio M.
Other Authors: Australian Research Council, Instituto Nacional de Ciência e Tecnologia da Criosfera, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Fundação de Amparo à Pesquisa do Estado de São Paulo, Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul, Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Format: Article in Journal/Newspaper
Language:English
Published: Springer Science and Business Media LLC 2021
Subjects:
Multidisciplinary
Greenland
Ice Sheet
Labrador Sea
Online Access:http://dx.doi.org/10.1038/s41598-021-84709-5
http://www.nature.com/articles/s41598-021-84709-5.pdf
http://www.nature.com/articles/s41598-021-84709-5
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Summary:Abstract The northern hemisphere experienced an abrupt cold event ~ 8200 years ago (the 8.2 ka event) that was triggered by the release of meltwater into the Labrador Sea, and resulting in a weakening of the poleward oceanic heat transport. Although this event has been considered a possible analogue for future ocean circulation changes due to the projected Greenland Ice Sheet (GIS) melting, large uncertainties in the amount and rate of freshwater released during the 8.2 ka event make such a comparison difficult. In this study, we compare sea surface temperatures and oxygen isotope ratios from 28 isotope-enabled model simulations with 35 paleoproxy records to constrain the meltwater released during the 8.2 ka event. Our results suggest that a combination of 5.3 m of meltwater in sea level rise equivalent (SLR) released over a thousand years, with a short intensification over ~ 130 years (an additional 2.2 m of equivalent SLR) due to routing of the Canadian river discharge, best reproduces the proxy anomalies. Our estimate is of the same order of magnitude as projected future GIS melting rates under the high emission scenario RCP8.5.

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