Supplementary data for 'From source to sink: part 1—characterization and Lagrangian tracking of riverine microplastics in the Mediterranean Basin'

Here we provide three compressed .zip folders.Two folders contain shapefiles and .csv datasets for the delineation of river basins and the corresponding estimations of microplastic flux at the Mediterranean and global scales:The folder MediterraneanSea.zip contains 549 river basins at a resolution of 0.08°.The folder Global.zip contains 9988 river basins at a resolution of 0.5°, as described by Weiss et al. (2021) (ref: https://doi.org/10.1126/science.abe0290).Both datasets are characterized by the following attributes:Id_R: the river basin identifierId_Ocean: the outlet ocean identifierpixel: the number of gridded cells constituting the river basin at a resolution of 0.5°S: the river basin surface in square kilometerssQ: the runoff in mm per yearsPop: the population density in the river basins in number of inhabitants per square kilometersMP : the specific estimate of microplastic inputs in kg per year per square kilometerMP: the total estimate of microplastic inputs in kg per yearThe third folder MiP_density_matrix_GLOBMED.zip contains the post-processing matrices calculated using the described Lagrangian simulation outputs. These matrices are used to map microplastic densities at the sea surface (ws+ for Figure 7 of the paper) and at the sea bottom (ws- for Figure 9). The files are in .txt format with header data, which allows them to be opened as rasters in QGIS, for example (same as .tif).The density matrices are given as the number of particles per pixel area (in 0.05° mesh size). To obtain the mapped concentrations, the densities should be divided by the pixel size in km², as specified in the pixarea.txt matrix.It should also be noted that, in our simulations, one Lagrangian particle represents 10,000 microplastics, thus a conversion factor of 1:10,000 should be applied to the density matrices to obtain values consistent with those shown in the published figures (see the method sub-section 'River MP fluxes').