Fig. 1: Location map.
Core PS97/085-3 is located in the central Drake Passage (red star), ~40 km north of the Polar Front (see Supplementary Fig. 1). Yellow dots mark sediment cores north of the Subantarctic Front6,7,8. Gray dots indicate Scotia Sea transect cores south of the Polar Front5. Core PS67/197-1 in the Scotia Sea is sensitive to changes in winter sea ice extent22. Light blue arrows show the Antarctic Circumpolar Current (ACC), the Cape Horn Current (CHC) and Malvinas Current (MC)64, while dark green-blue arrows denote Weddell Sea Bottom Water (WSBW, thick) and Weddell Sea Deep Water (WSDW, thin) flows. The white dotted line marks the average modern winter sea ice edge68. Dashed lines are the Subantarctic Front (SAF, pink), Polar Front (PF, purple) and the Southern Antarctic Circumpolar Current Front (SACCF, orange)17. The right bottom insert map is modified from Rintoul. (2018)2 shows current speed in the Southern Ocean, with warmer red colors representing higher current speeds. The white box shows the study area and the yellow line marks the Jason Track 10436. The figure is adapted from Wu et al.26.
