Investigating the sources and structure of chromophoric dissolved organic matter (CDOM) in the North Pacific Ocean (NPO) utilizing optical spectroscopy combined with solid phase extraction and borohydride reduction

As in the EAO the 'humic-like” component exhibited very similar, although not identical, optical and chemical properties to those observed for terrestrially-dominated estuarine and coastal environments, providing evidence that this component originates from a terrestrial source. Although this component dominated the absorption, marine contributions (i.e. UV bands) similar to those observed in the EAO were also observed. However, these components were found to absorb and emit primarily in the UV and were not efficiently extracted by the C18 columns, clearly showing that they are structurally distinct from the “humic-like” component.