Preprints
https://doi.org/10.5194/egusphere-2024-1915
https://doi.org/10.5194/egusphere-2024-1915
04 Jul 2024
 | 04 Jul 2024

Glacial-interglacial contrasts in the marine inorganic carbon chemistry of the Benguela Upwelling System

Szabina Karancz, Lennart J. de Nooijer, Bas van der Wagt, Marcel T. J. van der Meer, Sambuddha Misra, Rick Hennekam, Zeynep Erdem, Julie Lattaud, Negar Haghipour, Stefan Schouten, and Gert-Jan Reichart

Abstract. 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 that provides constraint on the drawdown of pCO2 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 ka BP, 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 (U37, 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.

Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this preprint. The responsibility to include appropriate place names lies with the authors.
Share

Journal article(s) based on this preprint

25 Mar 2025
Contrasts in the marine inorganic carbon chemistry of the Benguela Upwelling System since the Last Glacial Maximum
Szabina Karancz, Lennart J. de Nooijer, Bas van der Wagt, Marcel T. J. van der Meer, Sambuddha Misra, Rick Hennekam, Zeynep Erdem, Julie Lattaud, Negar Haghipour, Stefan Schouten, and Gert-Jan Reichart
Clim. Past, 21, 679–704, https://doi.org/10.5194/cp-21-679-2025,https://doi.org/10.5194/cp-21-679-2025, 2025
Short summary
Download

The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.

Short summary
Changes in upwelling intensity of the Benguela upwelling region during the last glacial...
Share