Plio‐Pleistocene Southwest African Hydroclimate Modulated by Benguela and Indian Ocean Temperatures

Rubbelke, Claire B.; Bhattacharya, Tripti; Feng, Ran; Burls, Natalie J.; Knapp, Scott; McClymont, Erin L.

Abstract

Future projections of southwestern African hydroclimate are highly uncertain. However, insights from past warm climates, like the Pliocene, can reveal mechanisms of future change and help benchmark models. Using leaf wax hydrogen isotopes to reconstruct precipitation (δDp) from Namibia over the past 5 million years, we find a long-term depletion trend (−50‰). Empirical mode decomposition indicates this trend is linked to sea surface temperatures (SSTs) within the Benguela Upwelling System, but modulated by Indian Ocean SSTs on shorter timescales. The influence of SSTs on reconstructed regional hydroclimate is similar to that observed during modern Benguela Niurn:x-wiley:00948276:media:grl66456:grl66456-math-0001o events, which bring extreme flooding to the region. Isotope-enabled simulations and PlioMIP2 results suggest that capturing a Benguela Niurn:x-wiley:00948276:media:grl66456:grl66456-math-0002o-like state is key to accurately simulating Pliocene, and future, regional hydroclimate. This has implications for future regional climate, since an increased frequency of Benguela Niurn:x-wiley:00948276:media:grl66456:grl66456-math-0003os poses risk to the ecosystems and industries in the region.

Citation

Rubbelke, C. B., Bhattacharya, T., Feng, R., Burls, N. J., Knapp, S., & McClymont, E. L. (2023). Plio‐Pleistocene Southwest African Hydroclimate Modulated by Benguela and Indian Ocean Temperatures. Geophysical Research Letters, 50(19), Article e2023GL103003. https://doi.org/10.1029/2023gl103003

• Journal Article Type: Article
• Acceptance Date: Sep 9, 2023
• Online Publication Date: Sep 29, 2023
• Publication Date: Oct 16, 2023
• Deposit Date: Oct 2, 2023
• Publicly Available Date: Oct 2, 2023
• Journal: Geophysical Research Letters
• Print ISSN: 0094-8276
• Electronic ISSN: 1944-8007
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 50
• Issue: 19
• Article Number: e2023GL103003
• DOI: https://doi.org/10.1029/2023gl103003
• Keywords: General Earth and Planetary Sciences; Geophysics
• Public URL: https://durham-repository.worktribe.com/output/1755136