Dataset: Phytoplankton pigment concentrations for samples collected from the upper 200 meters during the GP17-OCE cruise on R/V Roger Revelle (RR2214) in the South Pacific and Southern Oceans from December 2022 to January 2023

Pigments were collected using a conventional rosette, and sampled from the shallowest 4-6 depths on casts. Typically the surface sample was also taken via an underway towfish. Pigments were collected into 2-liter (L) amber bottles, triple rinsed with sample prior to filling. They were immediately filtered under vacuum through 25-millimeter (mm) GF/F filters. They were folded and placed inside aluminum foil packets, labeled with appropriate GEOTRACES numbers, and frozen at -80 degrees Celsius (°C).

Samples were analyzed at Oregon State University’s Ocean Ecology and Biogeochemistry Facilities (https://ceoas.oregonstate.edu/ocean-ecology-and-biogeochemistry-facilities). Their method for pigment analysis is based on the protocol described by Mantoura and Lewellyn (1983) and modified according to Bidigare et al. (1989). Briefly, samples are extracted for up to 48 hours in 100% acetone at -20°C, then analyzed on a Waters 2690 separations module equipped with a C18 column and full spectrum photodiode array detector. Pigment standards for calibration and response factor calculations are obtained from DHI Group in Denmark. An SOP is attached (HOT-Bidigare-HPLC_SOP.docx).