SeaFlow data v1: High-resolution abundance, size and biomass of small phytoplankton in the North Pacific

SeaFlow is an underway flow cytometer that provides continuous shipboard observations of the optical properties of the smallest phytoplankton. The instrument collects the equivalent of 1 sample every 3 minutes or every 1 km (for a ship moving at 10 knots) from the ship’s flow-through seawater system. The data set consists of SeaFlow-based cell abundance, cell size (equivalent spherical diameter) and carbon biomass for picophytoplankton populations, namely the cyanobacteria Prochlorococcus, Synechococcus and small-sized Crocosphaera (2-5 um), and small eukaryotic phytoplankton (&lt;5 μm ESD). Data were processed as described in Ribalet et al. (2019). Further information can be found on the SeaFlow website. <strong>New in version 1.5 </strong> Datasets now includes flow cytometric measurements from 64 cruises. Population-specific refractive indices were used to provide more accurate estimates of cell size for Prochlorococcus and Synechocococus and more conservative estimates for Crocospheara and small eukaryotes. The refractive index used per population and per cruise can be found here (where lwr = 1.41/1.3371, mid = 1.38/1.3371, upr = 1.36/1.3371). Abundances of Prochlorococcus were calibrated using discrete samples analyzed by an Influx BD cell sorter. The calibration factor for each cruise can be found here (where <em>a</em> represents the calibration factor, <em>inst</em> represents the instrument serial number and <em>sample</em> represents whether or not discrete samples were available for calibration)