2015 Elsevier Inc. All rights reserved. There are several sources of dissolved organic matter (DOM) to the Arctic Ocean, input from surrounding seas, input from river runoff and internal production by biological activity. The input from the surrounding seas is around 2501012gC year-1, but is accompanied by an outflow of nearly the same magnitude. No significant net transport of DOM can be deduced with the present data, indicating that the input by rivers and from surrounding seas as well as by biological production is balanced by the consumption by microbial degradation. Terrigenous DOM has been considered as relatively stable, but more recent studies show that at least part of it is degradable. The large input of terrigenous DOM makes the Arctic Ocean unique and offers us an additional oceanographic tracer for this ocean basin. In this chapter we use the chemical characteristics of Arctic DOM, including the elemental, isotopic, molecular level, and optical properties, to better describe the factors responsible for DOM distribution, transport, and fate.
