Based on shell concentrations of the planktonic foraminifera Neogloboquadrina pachyderma from vertically resolved plankton tow samples during cruises ARK-IV/3, ARK-XI/1, ARK-XIII/2, ARK-XV/1, ARK-XV/2, MSM44, MSM66, M21/4, M21/5, M39/4, MSM09/2, NEWP-92, NEWP-93, PS93.1, PS31, PS78, the base of the productive zone is calculated. The calculation is based on the assumption that the base of productive zone is located where shell concentration begins to substantially decline and it is calculated after Lončarić et al. (2006).
Based on shell concentrations of the planktonic foraminifera Neogloboquadrina pachyderma from vertically resolved plankton tow samples during cruises ARK-IV/3, ARK-XI/1, ARK-XIII/2, ARK-XV/1, ARK-XV/2, MSM44, MSM66, M21/4, M21/5, M39/4, MSM09/2, NEWP-92, NEWP-93, PS93.1, PS31, PS78 and (average) shell weights, the calcite mass flux is calculated (mg m-2 d¬-1).
For the quantification of the calcite production and loss in the upper water layer by the planktonic foraminifera Neogloboquadrina pachyderma in the Arctic ocean, we compiled data from vertical profiles in the upper water column of shell concentration, shell size and weights during summer. This data set includes new observations from the Fram Strait and Baffin Bay on shell concentration, shell size and weight, as well as calculated base of the productive zone and mass flux from both the new and published data.
Estimates of Last Glacial Maximum annual mean seawater temperatures at 50 m depth. The temperature estimates are derived using the Modern Analogue Technique using the ForCenS synthesis (https://doi.org/10.1594/PANGAEA.873570; https://doi.org/10.1038/sdata.2017.109) and World Ocean Atlas 1998 temperature (http://www.nodc.noaa.gov/oc5/woa98.html) for calibration. Dissimilarity to the core top data was calculated using the square-chord distance and the temperatures are the weighted averages of the 10 closest analogues. Estimates were averaged for sites where more than a single sample is available.
Understanding how the carbonate-saturation state of seawater affects the geochemistry of foraminiferal tests is still in an elementary phase. Our primary goals are to investigate how dissolution affects the primary stable oxygen isotope and Mg/Ca signals in eight shallow-, thermocline-, and deep-dwelling planktonic foraminifera from 47 sediment-surface samples of the South China Sea. Using an integrated approach (Mg/Ca ratios, ä18O values, test weights, scanning-electron micrographs), we will determine the onset of partial dissolution with depth and quantify the dissolution bias in Mg/Ca ratios in relation to changes in the carbonate-ion concentration of bottom waters. Our work will also provide an opportunity to evaluate the sensitivity of Mg/Ca ratios as a proxy for seawater corrosiveness and assess the applicability for past climate reconstructions.