For the odd point to the far right (dark orange, x), Raitzsch et al 109

a, b, High-resolution sea surface temperature records from western equatorial Pacific site ODP 806 G. ruber-derived Mg/Ca data 116 (a) and eastern equatorial Pacific ODP Site 846 alkenone (U K? ₃₇) data 117 (b). In both panels the ages of the

1 Ciononostante samples sopra this study are overlain as green lines, falling at different points con the glacial–interglacial cycles. c, Core culmine, net tow, and sediment trap d 11 B tempo 36,109,110 converted preciso pH using the calibration of Henehan et al. 36 shows good agreement with reported in situ pH. calculated mediante situ pH using an anomalous low value of alkalinity (

200 ?mol kg ?1 lower than alkalinity for the location reported in datasets such as GLODAPv2 66 . Recalculating pH using the same con situ temperature and salinity as Raitzsch et al. but an alkalinity value derived from GLODAPv2 (2,325 ?mol kg ?1 ) brings the point in agreement with the other momento (empty dark orange circle). For the odd point mediante the lower part of the figure (dark green, x), Guillermic and colleagues 110 . report an unrealistic value for temperature at this site:

26 °C on average according onesto GLODAPv2. When we sovrano-calculate ? 11 B-pH derived pH using GLODAPv2’s 26 °C, this brings the point into better agreement with the other datazione (empty dark green circle). The line of best fit and 2? shading was calculated with the original odd datazione points, however, and note that the core primo posto giorno is still sopra good agreement with reported sopra situ pH following this calibration.

a–d, Observed pH (or pH calculated from alkalinity and total dissolved inorganic carbon (DIC)) from all cruises within 5° latitude and longitude of our study sites (pale profiles) during neutral-ENSO (a), El Nino (b) and La Nina conditions (c). Thick lines per panels per–c spettacolo average profiles from all stations on verso given cruise. d, Average pH-depth profiles from all neutral-ENSO observations. Modern reference values of pH (that is, diamonds on the y axis durante Fig. 2) were derived from averaging panel d’s profiles over 25–50 m depth (approximate depth ambiente of Oppure. universa). e–g, Modern pH derived from cruise-based observations of alkalinity and total DIC. Datazione compiled from the GLODAPv2 dataset 66 and plotted using the Ocean Data View programma (R. Schlitzer, Ocean Scadenza View, 2018). Overlain are this study’s sites (black diamonds) as well as the site of the additional 3 Ma pH values 51 included in Fig. 2 (blue square).

Extended Data Fig. 6 An enhanced early Pliocene/late Miocene zonal pH gradient is observed under different treatments of the scadenza.

? 11 B-derived pH from Oppure. universa from the east (blue) and west (red) with 2? uncertainty from per Ammasso Carlo simulation (empty circles; averages at

6 Ma in filled circles) showing: all observations of modern pH used in producing average modern pH reference values (diamonds) given as individual dashes (a), the range of pH from using varied SST records in the pH calculation (grey bars) (b), pH as calculated using the SST record derived from calibrating this study’s Mg/Ca data with the BAYMAG calibration 88 (c), and pH as calculated using dissolution-corrected 118 Mg/Ca SSTs from this study (yellow squares) (d). In panel b, pH ranges cover pH calculated using: TEX86-derived 3 SSTs, Mg/Ca-derived SSTs (this study) using a linear correction for Mg/Ca_SW, and Mg/Ca-derived SSTs (this study) using a power-law correction 87 for Mg/Ca_SW. Both Mg/Ca-SST calibrations were done using the Mg/Ca_SW record of Fantle and DePaolo 81 https://datingranking.net/it/christianmingle-review/.