Particulate organic carbon concentrations in the western North Atlantic Ocean (May - June 2019)

Collection of particulate organic matter Particulate organic matter (POM) was collected by filtering between 5-15 liters of water through a 47-mm pre-combusted (400℃ for 6 hours) glass fiber filter (GF/F; nominal pore size 0.7 μm; for volumes filtered at each depth and station, see the dataset). POC analysis Particulate organic carbon was measured as described in Becker et al. (2020). In brief, triplicate filter punches from samples collected on pre-combusted (400℃ for 6 hours) glass fiber filters (GF/F) were placed in an acidic environment (concentrated HCl fumes) for 24 h to remove inorganic carbon. After drying for 24 h at 60 °C, the samples were packed in pre-combusted tin foil. C was quantified using an elemental analyzer (cario MICRO cube; Elementar Analysensysteme) using sulfanilamide for calibration. Limits of detection for POC was 0.001 mg C/L, based on the standard deviation of blank measurements.