Dataset belonging to "Contrasts in the marine inorganic carbon chemistry of the Benguela Upwelling System since the Last Glacial Maximum"

Upwelling regions are dynamic systems where relatively cold, nutrient- and CO2-rich waters reach to the surface from the deep. CO2 sink or source properties of these regions are dependent not only on the dissolved inorganic carbon content of the upwelled waters, but also on the efficiency of the biological carbon pump which constrains the drawdown of atmospheric CO2 in the surface waters. The Benguela Upwelling System (BUS) is a major upwelling region with one of the most productive marine ecosystems today. However, contrasting signals reported on the variation in upwelling intensities based on, for instance, foraminiferal and radiolarian indices from this region over the last glacial cycle indicate that a complete understanding of (local) changes is currently lacking. To reconstruct changes in the CO2 history of the Northern Benguela upwelling region over the last 27 kyr, we used a box core (64PE450-BC6) and piston core (64PE450-PC8) from the Walvis Ridge. Here, we apply various temperature and pCO2-proxies, representing both surface (UKʹ 37, δ13C of alkenones) and intermediate depth (Mg/Ca, B/Ca, S/Mg, δ11B in planktonic foraminiferal shells) processes. Reconstructed pCO2 records suggest enhanced storage of carbon at depth during the last glacial maximum. The offset between δ13C of planktonic (high δ13C) and benthic foraminifera (low δ13C) suggests an evidence of a more efficient biological carbon pump, potentially fuelled by remote and local iron supply through aeolian transport and dissolution in the shelf regions, effectively preventing release of the stored glacial CO2.