The photograph to the left shows the coast of Greenland as seen from the Northeast water polynya.
Dissolved organic material (DOM) in the Arctic ocean has the highest concentration in any ocean basin, but is mostly unknown on the molecular level. DOM is potentially an important factor in supporting the net heterotrohic open ocean in the Arctic. An increased riverine inflow has been suggested as a consequence of global warming and points to the importance of determining the role of riverine DOM in the Arctic carbon cycle. The Shelf-Basin Interaction model suggests a possible transport mechanism for DOM from the shelf to the open Arctic Ocean. My group has started compound-specific studies of DOM in the Arctic Ocean to:
- determine whether the high DOC concentrations in the Arctic Ocean include a higher concentration of biologically labile components than are found in other oceans.
- determine the relative biological lability of DOM from riverine inputs to the Arctic Ocean and compare to relative lability of DOM formed in situ.
Specifically, amino acids, neutral aldoses and low-molecular-weight organic acids will be studied. Analysis will be carried out with IC-PAD for neutral aldoses, with HPLC-Fluorescence for amino acids and with HPLC-Fluorescence/UV-Absorbance for organic acids. The presently available methods for organic acid analysis suffer from high practical detection limits due to poor sensitivity and contamination problems, therefore the initial work will be focused on developing a new method for organic acids.
In order to determine the background concentrations of biologically labile compounds in the Arctic Ocean, samples from the Arctic will be collected with ships of opportunity and these concentrations will be compared with values found in the Atlantic and Pacific Oceans. In order to answer the question of biological lability of riverine organic matter, samples from the McKenzie River will be obtained. The relative concentrations of biologically degradable components (normalized to DOC) will be compared with Arctic Basin water. The values for biological lability of DOM in different locations in the Arctic will be very valuable information for modeling studies of the Arctic ecosystem.
This research is supported by the Office of Polar Programs at the National Science Foundation, Grant # OPP-9815705
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