Dissolved organic matter characterization for seasonal synoptic sampling of 100 urban streams in Portland, Oregon (USA) from 2023-2024

This dataset contains dissolved organic matter characteristics from surface water samples collected at 100 urban stream locations in the greater Portland, Oregon metropolitan area. Samples were collected four times (July 2023, October 2023, January 2024, and May 2024) to capture spatial and seasonal variation in DOC concentrations. Fluorescent optical properties were measured on filtered water samples to understand the chemical composition of dissolved organic matter. Excitation-Emission Matrices (EEMs) were measured using a Horiba Aqualog spectrometer. DOM characteristics were quantified using both standard fluorescence and absorbance metrics as well as through parallel factor (PARAFAC) analysis. These data were collected as part of the Carbon in Urban Rivers Biogeochemistry (CURB) Project. Detailed field data and site data are published separately and can be linked using the “curbid” and “synoptic_event” columns in each dataset.