Surface and profile concentrations of trace metals and radionuclides near Station ALOHA

<p>Trace element water samples from KM1513 were collected with the MIT Automated Trace Element (ATE) sampler, deployed with a teflon-coated wire from the ship’s deck for surface water samples (collected at roughly 10 m depth), and with the ATEs attached to PVC “Vanes” designed to prevent contamination from the ship’s steel wire for samples collected at greater depth. Samples were filtered at 0.4 μm immediately after collection through polycarbonate track etched filters (Nucleopore) into 250 mL HDPE bottles and acidified to 0.012 M hydrochloric acid (ultrapure by quadruple distillation in a Vycor still; ~pH 2) at sea. Sampling and filtration followed published protocols used previously at Station ALOHA, for direct comparison (Fitzsimmons et al., 2015). These casts mostly aligned with Niskin cast station locations, but in some cases did not.</p>