Biological N2 gas from the ETNP St P2 in April 2012

In April 2012, on the R/V Thompson, biological N2 gas concentrations were sampled at St P2 and analyzed exactly as in Fuchsman et al. (2018). Water for replicates (n=2) was obtained from separate Niskin bottles on the same rosette by filling evacuated 185 mL gas flasks, under a local CO2 atmosphere where each flask was sealed with a Louwers-Hapert valve and contained dried mercuric chloride as a preservative. At the University of Washington School of Oceanography, head space gases were cryogenically processed to remove CO2, run through an inline CuO furnace to remove oxygen, and measured on a Finnegan Delta XL dual inlet isotope ratio mass spectrometer. Anoxic samples were measured against a standard that contained no oxygen. Total N2 gas concentrations in the ocean are a combination of N2 gas from equilibration with air when the water was last at the surface, abiotic elevation in concentrations from mixing, and biological production. The simplest way to obtain biological N2 gas concentrations is to remove background N2 gas in silico by subtracting N2 gas profiles from nearby oxygenated sites, in this case the oxic North Pacific (Chang et al., 2012; Fuchsman et al., 2018). These data support the paper "<b>Contributions of Vertically Migrating Metazoans to Sinking and Suspended Particulate Matter Fuel N</b>_{<strong>2</strong>}<b> Production in the Eastern Tropical North Pacific Oxygen Deficient Zone</b>."