FN Archimer Export Format PT J TI Leeuwin Current dynamics over the last 60 kyrs – relation to Australian extinction and Southern Ocean change BT AF Nürnberg, Dirk Kayode, Akintunde Meier, Karl J. F. Karas, Cyrus AS 1:1;2:1;3:2;4:3; FF 1:;2:;3:;4:; C1 GEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstr. 1-3, D-24148 Kiel, Germany Institute of Earth Science, Heidelberg University, Im Neuenheimer Feld 234, Heidelberg D-69120, Germany Universidad de Santiago de Chile, Av. Bernardo O’Higgins 3363, Santiago, Chile C2 IFM GEOMAR, GERMANY UNIV HEIDELBERG, GERMANY UNIV SANTIAGO, CHILE IN DOAJ TC 0 UR https://archimer.ifremer.fr/doc/00765/87658/93148.pdf https://archimer.ifremer.fr/doc/00765/87658/93149.pdf https://archimer.ifremer.fr/doc/00765/87658/98608.pdf https://archimer.ifremer.fr/doc/00765/87658/98609.pdf LA English DT Article CR MD 131 / AUSCAN BO Marion Dufresne AB The Leeuwin Current flowing southward along West Australia is an important conduit for the poleward heat transport and interocean water exchange between the tropical and the subantarctic ocean areas. Its past development, and its relationship to Southern Ocean change and to Australian ecosystem response, however is largely unknown. We here reconstruct sea surface and thermocline temperatures and salinities from foraminiferal-based Mg/Ca and stable oxygen isotopes from offshore southwest and southeast Australia reflecting the Leeuwin Current dynamics over the last 60 kyrs. Its variability resembles the biomass burning development in Australasia from ~60–20 ka BP implying that climate-modulated changes related to the Leeuwin Current most likely affected Australian vegetational and fire regimes. In particular during ~60–43 ka BP, warmest thermocline temperatures point to a strongly developed Leeuwin Current during Antarctic cool periods when the Antarctic Circumpolar Current weakened. The pronounced centennial-scale variations in Leeuwin Current strength appear in line with the migrations of the Southern Hemisphere frontal system and are captured by prominent changes in the Australian megafauna biomass. We argue that the concerted action of a rapidly changing Leeuwin Current, the ecosystem response in Australia, and human interference since ~50 BP enhanced the ecological stress on the Australian megafauna until a tipping point was reached at ~43 ka BP, after which faunal recuperation no longer took place. While being weakest during the last glacial maximum, the deglacial Leeuwin Current intensified at times of poleward migrations of the Subtropical Front. During the Holocene, the thermocline off South Australia was considerably shallower compared to the short-term glacial and deglacial periods of Leeuwin Current intensification. PY 2022 PD JAN SO Climate of the Past SN 1814-9332 PU Copernicus GmbH VL 18 IS 11 BP 2483 EP 2507 DI 10.5194/cp-2022-33 ID 87658 ER EF