Analyzing A High-Resolution Depth Profile of Fluorescent Dissolved Organic Matter to Better Understand the Relationships and Distribution of Marine Chromophoric and Fluorescent Dissolved Organic Matter

Madeline Lahm, Leanne Powers and Michael Gonsior, University of Maryland Center for Environmental Science, Chesapeake Biological Laboratory, Solomons, MD, United States
Fluorescent dissolved organic matter (FDOM) is the fraction of chromophoric dissolved organic matter (CDOM) that emits fluorescent light and is often used for tracking dissolved organic matter (DOM) in natural waters and their corresponding properties. The tracking of forms of dissolved organic matter is significant in monitoring the regulation of marine ecosystem processes and the understanding of global CDOM distribution. Despite the importance and progress in the field, the sources, distribution and chemical composition of marine CDOM and FDOM are still uncertain. In this study, we aim to analyze a high-resolution depth profile of FDOM in the water column using samples collected from 4530m to the surface at every 200m at the Bermuda Atlantic Time-series Study station. This analysis of fluorescence and UV-visible absorbance in a vertical FDOM high-resolution depth profile enhances our understanding of the relationship between marine CDOM and FDOM and their distribution.