Temporal Variability of Coloured Dissolved Organic Matter in the Canada Basin, Arctic Ocean (2007-2017)

Description

This thesis investigated coloured and fluorescent dissolved organic matter in the Canada Basin, Arctic Ocean from 2007 to 2017. The first interannual time-series of its kind in the Canada Basin incorporated the use of EEM-PARAFAC to validate a seven-component model. Statistical temporal tests revealed (1) an increasing protein-like intensity in the upper polar mixed layer (UPML); (2) increasing intensities of humic-like components in the halocline due to increasing freshwater content; and (3) no change in DOM composition in deeper Atlantic waters (AW) congruent with the long residence time of the water mass (> 30 years). The significant decline in sea ice concentration was related to a decrease in humic-like FDOM due to enhanced photodegradation and an increase in protein-like FDOM, likely the results of increased biological activities in surface layers. This research provides evidence that the changes in physical and biological environment in the Arctic regions have already profound impacts on the composition and distribution of FDOM.
Author Keywords: absorbance, Arctic Ocean, dissolved organic matter, fluorescence, parallel factor analysis, time-series