Spectroscopic Measurements and Multi-way Parallel Factor (PARAFAC) Analysis and Comparison of Lake Pontchartrain Dissolved Organic Matter (DOM) During Two Separate Large-Scale Mississippi River Flood Diversions

Abstract

The Mississippi River high water levels in 2011 and 2016 resulted in the opening of the Bonnet Carré Spillway (BCS), introducing nutrients and terrestrial sourced dissolved organic matter (DOM) into Lake Pontchartrain Estuary. The resulting dynamic change in concentration and composition of the DOM was measured using ultraviolet visible (A254, A350, SUVA254, and S275-295) and fluorescence spectroscopy (excitation emission matrices and fluorescence and biological indices). Additionally, the analysis was enhanced and individual fluorophores of DOM were determined using multi-way parallel factor analysis (PARAFAC). Through comparing the results of the 2011 dataset and 2016 dataset, similarities in the DOM composition during diversions were determined and variations of the overall DOM composition were identified and predicted to be the result in variations of temperature, sunlight, and rain fall.