MESO-SCOPE - KM1709 - Particulate Carbon and Nitrogen - Underway

These Simons Collaboration on Ocean Processes and Ecology (SCOPE) data products were produced by the University of Hawaiʻi at Mānoa with support from the Simons Foundation. The MESO-SCOPE (Microbial Ecology of the Surface Ocean - Simons Collaboration on Ocean Processes and Ecology) expedition collected oceanographic observations in the region north of the Hawaiian Islands with the aim of identifying the impact of mesoscale eddies on the ecosystem of the North Pacific Subtropical Gyre. The expedition targeted a mesoscale dipole north of the island of Oahu to characterize: 1) the horizontal variability in biogeochemical and ecological properties across the two eddies; and 2) Lagrangian temporal dynamics at the two eddy centers, with a particular focus on diel processes. The carbon and nitrogen content of particulate material (PC, PN) was collected by semi-automated and sequential filtration of the R/V Kilo Moana’s underway flow through seawater onto a combusted GFF filter. Following filtration, filters were folded in half and placed in combusted aluminum foil and stored at -80°C for later analysis. Post-cruise, all filters were thawed, acidified, and dried overnight at 60°C. Samples were then balled into Ag and Sn boats and plated for analysis. Organic carbon and total nitrogen content was analyzed using high-temperature combustion (1020 C) on a ThermoQuest NC 2500 elemental analyzer. Three standards with known %C and %N were weighed, folded in tin boats, and analyzed with the samples to develop the calibration equation for each run. The calibration equation was then used to calculate the mass (mg) of carbon and nitrogen in each sample using EAS Clarity Chromatography Station software. The standards are Cystine (Elemental Microanalysis, B2035, 11.66 %TN, 29.99 %TC), Atropine (Elemental Microanalysis, B2002, 4.84 %TN, 70.56%TC), and GoniLab Secondary Standard (low %C)-A1 (an internal standard of sediment from the Gulf of Mexico, MV0803, with low carbon - 0.12 %N, 1.3 %C). Samples were corrected for DOC/DON.