The upper layers of the Canadian Basin constitute a large reservoir of freshwater and buoyancy that derives from river runoff, sea-ice meltwater, and relatively fresh North Pacific waters. The size of the reservoir and fluxes of buoyancy to the sub-Arctic region vary with large-scale wind-stress patterns in the Northern latitudes. We use salinity, oxygen isotopes and nutrient concentrations to study the varying contribution from freshwater components in a series of Arctic Ocean cruises between 1989 and 2005.
We put these temporal changes in the context of the time-mean Arctic-wide distribution of water-mass tracers based on 30 years of modern research cruises there. We also link the component shifts to basic indices of Arctic atmospheric variability. Finally, we compare different methods for performing the decomposition, based on different combinations of tracers. We address uncertainties in end-member definition that have led to conflicts between water mass estimates by different research groups, and show that the these methods can reconciled, at least in the Chukchi Sea region, through a careful treatment of biological processing and mixing over the Arctic shelf seas.
Presented by Robert Newton, Peter Schlosser, Richard Mortlock, and Andrew Babbin at the 2012 Ocean Sciences Meeting, Salt Lake City, UT
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