For the odd point puro 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 Pero samples in this study are overlain as green lines, falling at different points per the glacial–interglacial cycles. c, Core sommita, net tow, and sediment trap d 11 B data 36,109,110 converted puro pH using the calibration of Henehan et https://datingranking.net/it/blackdatingforfree-review/ al. 36 shows good agreement with reported sopra situ pH. calculated durante situ pH using an anomalous low value of alkalinity (
200 ?mol kg ?1 lower than alkalinity for the location reported mediante datasets such as GLODAPv2 66 . Recalculating pH using the same per situ temperature and salinity as Raitzsch et al. but an alkalinity value derived from GLODAPv2 (2,325 ?mol kg ?1 ) brings the point sopra agreement with the other scadenza (empty dark orange circle). For the odd point con 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 sicuro GLODAPv2. When we regnante-calculate ? 11 B-pH derived pH using GLODAPv2’s 26 °C, this brings the point into better agreement with the other data (empty dark green circle). The line of best fit and 2? shading was calculated with the original odd tempo points, however, and note that the core vertice data is still in good agreement with reported durante 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 mediante 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 sopra Fig. 2) were derived from averaging panel d’s profiles over 25–50 m depth (approximate depth nicchia ecologica of O. universa). e–g, Modern pH derived from cruise-based observations of alkalinity and total DIC. Tempo compiled from the GLODAPv2 dataset 66 and plotted using the Ocean Scadenza View software (R. Schlitzer, Ocean Datazione View, 2018). Overlain are this study’s sites (black diamonds) as well as the site of the additional 3 Bensi 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 data.
? 11 B-derived pH from Oppure. universa from the east (blue) and west (red) with 2? uncertainty from verso Caterva 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/CaSW, and Mg/Ca-derived SSTs (this study) using a power-law correction 87 for Mg/CaSW. Both Mg/Ca-SST calibrations were done using the Mg/CaSW record of Fantle and DePaolo 81 .
