Fig. 4: ODP site 982 absolute coccolith clumped isotope calcification temperatures agree better with alkenone temperatures calculated using a calibration that considers season and depth of production.
a Δ47 calcification temperatures (2–10 μm; blue dots), and alkenone-derived temperatures from this study as in Fig. 2, including estimates using the core top20 (orange dots), BAYSPLINE21 (pale pink shade), and a calibration that considers the season and depth of production (17 green dots). From the study of Super et al.8: alkenone temperature record applying the core top20 (pink line) and a calibration that considers the season and depth of production17 (blue-green line). The latter generally agrees with absolute temperatures derived from coccolith Δ47 (blue dots) and those derived from our alkenones calculated using the same season-depth calibration (green dots). Pale pink shaded area represents the 95% CI according to the BAYSPLINE calibration. Alkenone temperatures also calculated from the published coretop \({{{{\rm{U}}}}}_{37}^{{{{\rm{k}}}}{\prime} }\) value17 of our same site. Coccolith Δ47 calcification temperatures from a core top (<10 μm) at our same location17 (blue diamond) fit well modern ocean sea surface temperatures (SST red horizontal line). Error bars in coccolith Δ47 calcification temperatures record denote the 95% CI. b Cenozoic Global Reference deep-sea benthic foraminifer oxygen Isotope Dataset (CENOGRID)3.
