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A global compilation of in situ data is useful to evaluate the quality of ocean-colour satellite data records. Here we describe the data compiled for the validation of the ocean-colour products from the ESA Ocean Colour Climate Change Initiative (OC-CCI). The data were acquired from several sources (including, inter alia, MOBY, BOUSSOLE, AERONET-OC, SeaBASS, NOMAD, MERMAID, AMT, ICES, HOT and GeP&CO) and span the period from 1997 to 2018. Observations of the following variables were compiled: spectral remote-sensing reflectances, concentrations of chlorophyll a, spectral inherent optical properties, spectral diffuse attenuation coefficients and total suspended matter. The data were from multi-project archives acquired via open internet services or from individual projects, acquired directly from data providers. Methodologies were implemented for homogenization, quality control and merging of all data. No changes were made to the original data, other than averaging of observations that were close in time and space, elimination of some points after quality control and conversion to a standard format. The final result is a merged table designed for validation of satellite-derived ocean-colour products and available in text format. Metadata of each in situ measurement (original source, cruise or experiment, principal investigator) was propagated throughout the work and made available in the final table. By making the metadata available, provenance is better documented, and it is also possible to analyse each set of data separately. This paper also describes the changes that were made to the compilation in relation to the previous version (Valente et al., 2016). The compiled data are available at https://doi.org/10.1594/PANGAEA.898188 (Valente et al., 2019)., Sí

Suspended particulate matter (SPM) significantly impacts water clarity, degrading underwater electro-optical detection systems. It is also comprised of the living, detrital, and minerogenic particles that contribute to oceanic biogeochemical cycling. Models designed to derive SPM from optical properties such as particulate backscattering and attenuation have been largely empirical in nature, i.e., simple linear relationships, and therefore fluctuate with varying particle composition. Consequently, such models perform well regionally and/or temporally, but their applicability is constrained. An analytical inversion model has been developed to quantitatively interpret scattering measurements in terms of SPM. The algorithm requires measurements of backscattering and spectral attenuation. These measurements can be made with commercial-off-the-shelf technology suitable for deployment on compact autonomous platforms, thus having the potential to dramatically increase spatial and temporal resolving capabilities for SPM. Recent work evaluates the role of particle size ranges in greater detail and assesses performance for multiple data sets including the GlobCOAST data set, a large, diverse data set of high quality SPM and optical property measurements.