Biogeochemical data of NEREA Augmented Observatory

Analyses are performed using a Flow-Sys III Systea auto-analyzer using the methods reported by Hansen and Grasshoff (1983), slightly modified, for inorganic nutrients and after digestion at 120 °C for 30 minutes, using the adjustments proposed by Valderrama, 1981 to the original methods by Koroleff (1976 a, b). DOC analysis is carried out by high-temperature catalytic oxidation with a Shimadzu TOC analyzer (TOC-Vcsn) following the methods described in Santinelli 2015. POC analysis is conducted using a variable volume (1-3 litres) of seawater filtered on GF/F filters. After filtration, filters are rinsed with deionized water and stored at -20 °C. The analyses are performed with a Thermo Scientific FlashEA 1112 elemental analyzer (Thermo Fisher Scientific) following (Hedges and Stern 1984) and using cyclohexanone-2,4-dinitrophenylhydrazone as standard.