Rapid global ocean-atmosphere response to Southern Ocean freshening during the last glacial

Turney, C. S.M. et al. (2017) Rapid global ocean-atmosphere response to Southern Ocean freshening during the last glacial. Nature Communications, 8, 520. (doi: 10.1038/s41467-017-00577-6) (PMID:28900099) (PMCID:PMC5595922)

Abstract

Contrasting Greenland and Antarctic temperatures during the last glacial period (115,000 to 11,650 years ago) are thought to have been driven by imbalances in the rates of formation of North Atlantic and Antarctic Deep Water (the ‘bipolar seesaw’). Here we exploit a bidecadally resolved 14C data set obtained from New Zealand kauri (Agathis australis) to undertake high-precision alignment of key climate data sets spanning iceberg-rafted debris event Heinrich 3 and Greenland Interstadial (GI) 5.1 in the North Atlantic (~30,400 to 28,400 years ago). We observe no divergence between the kauri and Atlantic marine sediment 14C data sets, implying limited changes in deep water formation. However, a Southern Ocean (Atlantic-sector) iceberg rafted debris event appears to have occurred synchronously with GI-5.1 warming and decreased precipitation over the western equatorial Pacific and Atlantic. An ensemble of transient meltwater simulations shows that Antarctic-sourced salinity anomalies can generate climate changes that are propagated globally via an atmospheric Rossby wave train.

• Item Type: Articles
• Additional Information: This work was funded by the Australian Research Council (FL100100195, DP170104665 and SR140300001) and the Natural Environment Research Council (NE/H009922/1 and NE/H007865/1).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Staff, Dr Richard
• Authors: Turney, C. S.M., Jones, R. T., Phipps, S. J., Thomas, Z., Hogg, A., Kershaw, A. P., Fogwill, C. J., Palmer, J., Bronk Ramsey, C., Adolphi, F., Muscheler, R., Hughen, K. A., Staff, R. A., Grosvenor, M., Golledge, N. R., Rasmussen, S. O., Hutchinson, D. K., Haberle, S., Lorrey, A., Boswijk, G., and Cooper, A.
• College/School: College of Science and Engineering > Scottish Universities Environmental Research Centre
• Journal Name: Nature Communications
• Publisher: Nature Research
• ISSN: 2041-1723
• ISSN (Online): 2041-1723
• Copyright Holders: Copyright © 2017 The Authors
• First Published: First published in Nature Communications 8:520
• Publisher Policy: Reproduced under a Creative Commons License