A northward shift of the southern westerlies during the Antarctic cold reversal: evidence from Tasmania

dc.contributor.authorAlexander, Jen_AU
dc.contributor.authorFletcher, MSen_AU
dc.contributor.authorPedro, JBen_AU
dc.contributor.authorMariani, Men_AU
dc.contributor.authorBeck, KKen_AU
dc.contributor.authorBlaauw, Men_AU
dc.contributor.authorHodgson, Den_AU
dc.contributor.authorHeijnis, Hen_AU
dc.contributor.authorGadd, PSen_AU
dc.contributor.authorLisé-Pronovost, Aen_AU
dc.date.accessioned2024-04-10T02:50:19Zen_AU
dc.date.available2024-04-10T02:50:19Zen_AU
dc.date.issued2018-12-10en_AU
dc.date.statistics2023-03-16en_AU
dc.description.abstractThe Last Glacial Termination (LGT) was interrupted in the Southern Hemisphere by the Antarctic Cold Reversal (ACR; 14.7 to 13 ka), a millennial-scale cooling event that coincided with the Bølling– Allerød warm phase in the North Atlantic (14.7 to 12.7 ka). This inter-hemispheric asynchrony of climate change through the LGT, the bipolar seesaw, has been theoretically linked to latitudinal shifts in the southern westerly wind belt (SWW) and their proposed influence over the global carbon cycle via wind-driven upwelling of CO2 rich deep waters in the Southern Ocean (SO). However, while climate models and theory predict a northward shift of the SWW during the ACR in response to ocean-atmosphere heat dynamics, proxy-based reconstructions disagree on the behaviour of the SWW through this interval, and the role of the SWW during the LGT remains contested. Here we present terrestrial proxy palaeoclimate data (pollen, μXRF geochemistry, charcoal) from multiple lakes across Tasmania (40-44⁰S), an island located at the northern edge of the SWW. Our data reveal a clear SWW increase over Tasmania during the ACR, synchronous with reduced SWW-driven upwelling in the SO at the southern edge of the SWW. When combined with evidence from Antarctic ice cores and terrestrial records from New Zealand and Patagonia our results suggest a hemisphere-wide migration of the SWW during the LGT, lending support to the hypothesis that changes in wind-driven ventilation of CO2 from the Southern Ocean were a key driver of the global carbon cycle during the LGT. © The Authors.en_AU
dc.identifier.citationAlexander, J., Fletcher, M.-S., Pedro, J., Mariani, M., Beck, K., Blaauw, M., Hodgson, D., Heijnis, H., Gadd, P., & Lise-Pronovost, A. (2018). A northward shift of the southern westerlies during the Antarctic cold reversal: evidence from Tasmania. Paper presented at the AQUA Biennial Conference, Canberra, 10-14th December 2018. (pp. 61). Retrieved from: https://aqua.org.au/wp-content/uploads/2019/10/AQUA-2018-Program.pdfen_AU
dc.identifier.conferenceenddate2018-12-14en_AU
dc.identifier.conferencenameAQUA Biennial Conference, Canberra 2018en_AU
dc.identifier.conferenceplaceCanberraen_AU
dc.identifier.conferencestartdate2018-12-10en_AU
dc.identifier.pagination61en_AU
dc.identifier.urihttps://aqua.org.au/wp-content/uploads/2019/10/AQUA-2018-Program.pdfen_AU
dc.identifier.urihttps://apo.ansto.gov.au/handle/10238/15557en_AU
dc.language.isoenen_AU
dc.publisherAustralasian Quaternary Associationen_AU
dc.relation.urihttps://aqua.org.au/wp-content/uploads/2019/10/AQUA-2018-Program.pdfen_AU
dc.subjectWinden_AU
dc.subjectTasmaniaen_AU
dc.subjectQuaternary perioden_AU
dc.subjectCoolingen_AU
dc.subjectSouthern Hemisphereen_AU
dc.subjectClimatic changeen_AU
dc.subjectPollenen_AU
dc.subjectCharcoalen_AU
dc.subjectAntarcticaen_AU
dc.subjectNew Zealanden_AU
dc.subjectDrill coresen_AU
dc.titleA northward shift of the southern westerlies during the Antarctic cold reversal: evidence from Tasmaniaen_AU
dc.typeConference Presentationen_AU
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