Particles Volume scattering, backscattering, POC, phytoplankton carbon, using backscattering sensor [BB3] (WETLabs ECO-BB3) during the Tara Pacific Expedition 2016-2018

The Tara Pacific expedition (2016-2018) sampled coral ecosystems around 32 islands in the Pacific Ocean, and sampled the surface of oceanic waters at 249 locations, resulting in the collection of nearly 58,000 samples. The expedition was designed to systematically study corals, fish, plankton, and seawater, and included the collection of samples for advanced biogeochemical, molecular, and imaging analysis. Here we provide the continuous dataset originating from backscattering sensor [BB3] (WETLabs ECO-BB3) instruments acquiring continuously during the full course of the campaign. Surface seawater was pumped continuously through a hull inlet located 1.5 m under the waterline using a membrane pump (10 LPM; Shurflo), circulated through a vortex debubbler, a flow meter, and distributed to a number of flow-through instruments. The backscattering sensor [BB3] (WETLabs ECO-BB3) was added to the underway system to measure the volume scattering function [VSF] at 124° and 3 wavelengths (470, 532, 650 nm). The flow was automatically directed through a 0.2 µm filter for 10 minutes every hour before being circulated through the [BB3] allowing the calculation of particulate backscattering [bbp] by removing the signal due to dissolved matter, drift, and biofouling (Slade et al. 2010, doi:10.1175/2010JTECHO755.1). The particulate organic carbon concentration [poc] was estimated by applying an empirical relation between measured [poc] and [bbp] (Cetinić et al. 2012, doi:10.1175/2010JTECHO755.1). Phytoplankton organic carbon [cphyto] was estimated by an empirical relationship with [bbp] (Graff et al. 2015, doi:10.1016/j.dsr.2015.04.006).