This is the third update to the first release of the Pelagic Size Structure database (PSSdb), correcting an error in the size classes. (The size ratio between consecutive bins is no the same across all size ranges/categories). The PSSdb scientific project is investigating the global particle size distributions measured from multiple pelagic imaging systems. These devices include the Imaging Flow Cytobot (Olson and Sosik 2007), the ZooScan (Gorsky et al. 2010), and the Underwater Vision Profiler (Picheral et al. 2010). The data sources come from Ecotaxa (https://ecotaxa.obs-vlfr.fr, Ecopart (https://ecopart.obs-vlfr.fr), and Imaging FlowCytobot dashboards (https://ifcb.caloos.org/dashboard and https://ifcb-data.whoi.edu/dashboard).

This initial dataset is composed of two products, separated by imaging device:

• Product 1a includes size distributions calculated from normalized biovolume (NBSS) and normalized abundance (PSD) of plankton and particles within a set of pre-defined size classes (expressed in both biovolume and equivalent circular dimater), averaged by year and month, and in 1-degree longitude/latitude grid cells.


• Product 1b includes the results of NBSS and PSD regression fit parameters (slopes, intercepts, coefficient of determination R²), averaged by year and month, and in 1-degree longitude/latitude grid cells. The regression parameters are defined using ordinary least squares linear regressions applied to log₁₀ transformed normalized biovolume / normalized-abundance and biovolume / diameter-size class values.