Figure 6: Schematic representation of South Pacific overturning circulation.
From: Radiocarbon constraints on the extent and evolution of the South Pacific glacial carbon pool
(a) Glacial pattern: northernmost extent of sea ice and SWW. Increased AABW-salinity by brine rejection favours stratification. Increased dust input promotes primary production and drawdown of CO2. (b) Deglacial pattern: upwelling induced by southward shift of Antarctic sea ice and SWW. The erosion of the deep-water carbon pool releases 14C-depleted CO2 towards the atmosphere. Following air–sea gas exchange, the outgassing signal is incorporated into newly formed AAIW (light blue shading). Blue shading: poorly ventilated old and CO2-rich waters; Darkest shading 2,500–3,600 m: water level influenced by hydrothermal CO2. Green arrows: intermediate water; orange arrows: deep-water; light-blue areas: sea ice; SWW: Southern Westerly Winds; coloured circles: sediment cores (colour coding according to Fig. 2); black circle: SO213-79-2—no glacial data; and circular arrows: diffusional and diapycnal mixing.
