Fig. 4

Subantarctic carbonate counter pump strength and biological pump efficiency coupled with circulation pattern and atmospheric pCO₂ during the last deglaciation. a–c Noëlaerhabdacea, coccolith and planktonic foraminifera calcite masses (mg/g of sediment) at site MD07-3088, with errors bars of ±3% and ±20%, respectively. d Br/Ca ratio as an indicator of POC/PIC rain ratio and thus biological carbon pump efficiency (see Supplementary Fig. 3). e Δ δ¹³C = δ¹³C _{G. bulloides}  – δ¹³C _{C. wuellerstorfi} ¹⁴. f Atmospheric pCO₂ from WDC⁵⁶. Smoothed curves (thick lines of a–c, e and d) use three and eleven-point moving averages respectively. LG and LGIT are for Late Glacial and Last Glacial-Interglacial Transition, respectively. Yellow shading marks periods of reinvigorated SO upwelling (associated with enhanced sea surface fertility conditions and higher [CO_2aq]) during the last deglaciation, in conjunction to higher CCP strength and subdued biological pump efficiency, at times of increased atmospheric pCO₂