A comparative study of optical and size properties of dissolved organic matter in the lower Mississippi River and Pearl River

Abstract

A comparative study of dissolved organic matter (DOM) was conducted in the lower Mississippi River and Pearl River using monthly water samples. The Mississippi River exhibited lower dissolved organic carbon concentrations with minimal seasonal shifts. Conversely, the Pearl River showed higher concentrations driven by terrestrial runoff and distinct seasonal patterns. High-molecular-weight fractions displayed unique optical signatures. Major flood events increased organic material pulses, highlighting how shifting climates and hydrology affect coastal waters.