Chemical Analysis of CDOM Sources in Danish Coastal Waters of the Baltic Sea-North Sea Mixing Zone

摘要

The long term goal is to improve the Navy's prediction of the distribution of chromophoric dissolved organic matter (CDOM) in the littoral battlespace through measurement of its specific chemical properties. In the larger context of water mass mixing, the long term goal is to model the distribution of CDOM inputs from multiple sources. The study site is the Kattegat and Belt Sea at the entrance to Baltic Sea, however the approach was designed for implementation is other regions of Navy interest. The objective of this project is to provide the means to chemically validate the multiple sources of CDOM in a complex mixing environment through advanced chemical measurements of CDOM. The field work of this project was carried out in the Baltic Sea-North Sea mixing zone at the entrance to the Baltic Sea. The Baltic Sea is a large fjord greatly influenced by freshwater inflow from its large drainage basin and having a limited exchange with the North Sea (Atlantic Ocean). As a result its waters have a high content of terrestrially derived organic material. Danish marine monitoring cruises with R/V Gunnar Thorson were used as a sampling platform for the project. The cruises covered 26 stations (Fig. 1). Samples were taken for optical and chemical measurements of CDOM. Data for other water constituents and properties were made available from the monitoring program (temperature, salinity, chlorophyll, nutrient concentrations). At approximately 90% of the monitoring stations, samples for dissolved organic carbon (DOC) concentration and stable isotope value delta(sup 13)(C- DOC) were taken.