An 800-kyr planktonic 𝜹¹⁸O stack for the West Pacific Warm Pool

Abstract

Abstract. The West Pacific Warm Pool (WPWP) exhibits different glacial-interglacial climate variability than high latitudes, and its sea surface temperatures are thought to respond primarily to changes in greenhouse gas concentrations. To better characterize the orbital scale climate response of the WPWP, we constructed a planktonic 𝛿18O stack (average) of 11 previously published WPWP records of the last 800 kyr, available at https://doi.org/10.5281/zenodo.8190829 (Bowman et al., 2023), using new Bayesian alignment and stacking software BIGMACS. Similarities in stack uncertainty between the WPWP planktonic 𝛿18O stack and benthic 𝛿18O stacks also constructed using BIGMACS demonstrate that the software performs similarly well when aligning regional planktonic or benthic 𝛿18O data. Sixty-seven radiocarbon dates from four of the WPWP cores suggest that WPWP planktonic 𝛿18O change is nearly synchronous with global benthic 𝛿18O during the last glacial termination. However, the WPWP planktonic 𝛿18O stack exhibits less glacial/interglacial amplitude and less spectral power at all orbital frequencies than benthic 𝛿18O stacks. We assert that the WPWP planktonic 𝛿18O stack provides a useful representation of orbital-scale regional climate response and a regional alignment target, particularly for the higher resolution 0–450 ka portion of our stack.