Optical properties and fluorescent components of dissolved organic matter in water and sediment porewater and their benthic fluxes in the Pearl River Estuary

We collected water and sediment samples from the Pearl River Estuary (PRE) in June-July 2021. We measured absorbance and fluorescence properties of the dissolved organic matter (DOM) in water column and sediment porewater. We calculated chromophoric dissolved organic matter (CDOM) and fluorescent dissolved organic matter (FDOM) parameters including spectral slopes (S275-295 and S350-400) and CDOM spectral slope ratio (SR), as well as humification index (HIX) and the biological index (BIX). Parallel factor analysis (PARAFAC) was conducted to decompose the EEMs dataset to Five fluorescent components, including three terrestrial humic-like components and two protein-like components.