Studies conducted over the past decade indicate that the Arctic may be both a sensitiveindicator of climate change and an active agent in climate variability. Although progress has been made in understanding the Arctic'scoupled atmosphere-ice-ocean system, documentation of its evolution is hindered by a sparse data archive. This observational gap represents a critical shortcoming of the 'global' ocean observing system's ability to quantify the complex interrelated atmospheric, oceanic, and terrestrial changes now under way