Core-top carbon isotope measurements of dinoflagellate cysts

Description

The here deposited data represents stable carbon isotope measurements of dinoflagellate cyst (dinocyst) taxa isolated from core-top sediments. Carbon isotope data were generated using laser-ablation / nano-combustion / gas chromatography isotope ratio mass spectrometry (LA-nC-GC/IRMS) and each measurement represents 3-7 individual, hand-picked, dinocysts. A more detailed description of sample and data processing can be found here: https://bg.copernicus.org/preprints/bg-2022-118/ (updated with final version once available). The data were used to test dependency of carbon isotope fractionation to environmental parameters, most notably CO2, in order to construct a pCO2 proxy based on dinocyst carbon isotope fractionation. Carbon isotope data for five species (Operculodinium centrocarpum, Spiniferites ramosus, Spiniferites elongatus, Spiniferites mirabilis and Impagidinium aculeatum are presented, from 19 localities in the Atlantic Ocean and Mediterranean sea (listed in the data files), as well as pre-industrial material from the North Atlantic Ocean (ENAM9606, 55.650 ºN, -13.985 ºE). Three data files (summary and raw measurements for the core-tops and pre-industrial samples) are added. The summary file contains the data to calculate carbon isotope fractionation (ep) for each core-top sample and species (average raw and corrected dinocyst d13C, d13C of dissolved inorganic carbon (DIC), temperature) and the environmental parameters (pCO2, NO3, PO4, Si, temperature, salinity, alkalinity) used to compare to the dinocyst carbon isotope data. The raw measurement data file for the contains the sample identifier which links to the summary file, the species and signal-size and d13C value for each of the 949 individual measurements and similar file is included for the pre-industrial samples from ENAM9606 (n = 137). A signal-size dependent correction is applied based to eliminate small drift induced by background C (d13C adjusted). After this step, a disqualifier is given if the data is excluded based on too low signal intensity (below cut-off / BCO) or represents a statistical outlier within the d13C population of that specific sample and species (OUT). The adjusted d13C data without disqualifiers is included in the 'corrected d13C' and used in the summary file and statistical tests (see also https://bg.copernicus.org/preprints/bg-2022-118/). Species abbrevations: Operculodinium centrocarpum "Ocen", Spiniferites ramosus "Sram", S. elongatus, "Selon", S. mirabilis "Smira", Impagidinium aculeatum "Iacul".

Steps to reproduce

A detailed description of the methods, analytical precision and data treatment can be found here: https://bg.copernicus.org/preprints/bg-2022-118/

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