Changes in the Canada Basin: Results From Beaufort Gyre Observing Program/Joint Ocean Ice Studies Expeditions, 2003-2014.

Annual expeditions, that make use of ships, moorings and ice tethered platforms, have monitored oceanographic conditions in the Beaufort Gyre Region of the Canada Basin since 2003. These basin-wide surveys, together with available earlier data, show linkages between the physical, geo-chemical and ecosystem components during a period of rapid change, largely forced by increased multi-year ice melt and a prolonged anticyclonic phase of the Arctic Ocean circulation. The resulting Ekman convergence has led to a progressive accumulation of river and ice-melt-derived freshwater within the gyre, an increase in surface stratification and depression of the halocline. These changes in physical state have led to a decrease in aragonite saturation state, a deepening of the top of the nutricline and subsurface chlorophyll maximum and a shift in phytoplankton size spectra. Recent years have shown a slight relaxation of the Beaufort Gyre, in addition to large variation in ice cover, leading to informed speculation that the gyre may now be poised to release some of its accumulated freshwater as a salinity anomaly into the global system.