ALBERT

Description: This dataset collection includes boron isotope, Mg/Ca, and Al/Ca data from planktonic foraminifera, reconstructed sea surface temperature, seawater pH and atmospheric CO2 concentrations, calculated Global Mean Temperature and Climate Sensitivity estimates, and recalculated seawater pH and atmospheric CO2 estimates from published planktonic foraminiferal boron isotope data.

Description: The dataset includes time series of global mean temperature for the Eocene, using a combination of sea surface temperature reconstructions and model derived estimates of global mean temperatures. These are coupled to the atmospheric CO2 reconstructions, translated into CO2 forcing relative to preindustrial, to calculate the evolving climate sensitivity for the Eocene. Both equilibrium climate sensitivity and earth system sensitivity are provided.

Description: In this dataset, we compile published records of seawater pH and atmospheric CO2 from foraminiferal δ11B are re-calculated using our current constrains and processing scenarios for the Eocene, for consistency to the new data. The re-calculation includes no vital effect treatment (for T. sac like species of planktonic foraminifera the offset in d11B at Eocene d11Bsw conditions is smaller than analytical uncertainty), no pH correction on Mg/Ca-temperature relationship (T. sac like species) and incorporating MyAMI for carbonate system calculations (https://github.com/MathisHain/MyAMI).

Description: Water was collected for net primary production (NPP) incubations and total and size-fractionated chlorophyll a from multiple depths spanning the euphotic zone, using a CTD-rosette equipped with 24 10L Niskin bottles. For NPP, water from 6 depths spanning the euphotic zone (0.1% of surface irradiance) were incubated in situ during the 5 Lagrangian cycles sampled during SalpPOOP. NPP was assessed using carbon-14 (14C) assays, with 24-hour incubations that integrated respiration/production balance over the dark and light periods of the diel cycle. Seawater samples (1.3 L) were collected into an acid-rinsed polycarbonate bottle from pre-dawn CTD casts (~2:00 h each day of each cycle) at six depths spanning the euphotic zone. The bottles were then spiked with 0.1 mCi 14C-bicarbonate (DHI, Denmark or Perkin-Elmer, USA) before triplicate controls on ethanolamine were taken to quantify initial radioactivity at each depth incubation. After gentle mixing, the 'hot' 1.3 L was dispensed into three light and one dark bottles (320 mL acid-cleaned polycarbonate) that were incubated in situ on the free-drifting array. After recovery, the entire content of the bottles were filtered onto 0.2 µm pore-size 25-mm polycarbonate filters and kept frozen until analysis. Once on land, filters were acidified with 200 µL 0.5 N HCL, Hi Safe 3 liquid scintillation cocktail was added and disintegrations per minute were then determined using a scintillation counter following procedures described in Gutiérrez‐Rodríguez et al (2020 doi:10.1029/2019JC015550). NPP of multiple casts (2 to 4) conducted during each experimental cycle were averaged to obtain cycle estimates of primary production. If only one estimate per depth was available, the std is indicated as n.d. Samples for total Chlorophyll a (Chl a) analysis were filtered on‐board on 25mm Whatman GF/F filters using low vacuum (〈200 mm Hg). The filters were folded, wrapped in aluminum foil, flash frozen in liquid nitrogen and kept at −80 °C until analysis. For size fractionated Chl a analysis (0.2–2, 2–20, and 〉20 μm), 250 ml of seawater were sequentially filtered through a 20 μm polycarbonate filter first (by gravity), and then sequentially through 2‐ and 0.2‐μm polycarbonate filters under low pressure vacuum. Filters were folded and stored in 1.5 ml cryovials, flash frozen in liquid nitrogen, and stored at −80 °C. Analyses was done following 90% acetone extraction using standard fluorometric methods with a Turner Design 10AU fluorometer after Strickland and Parsons (1972 doi:10.1002/iroh.19700550118).