On Arctic and Atlantic halocline interactions in Baffin Bay

Physical measurements from 1928--2001 and geochemical measurements from 1997 were used to examine water interaction and mixing in the Baffin Bay region. Interactions between inputs from the Canadian Archipelago and the North Atlantic were apparent throughout the study area, but most notably near the Lancaster Sound/North Water region and Davis Strait. The Lancaster Sound/North Water region appeared determinant in establishing the downstream structure of the Baffin Current, whereas Davis Strait regulated both exchange with the North Atlantic and the recirculation of Baffin Current waters toward central Baffin Bay. Results from an advective-diffusive model indicated that Canadian Archipelago outflow might play a dominant role in maintaining the intermediate and deep structures of central Baffin Bay. Further to this, a hypothesis was developed relating central basin structure to variations in Baffin Current flow and recirculation near Davis Strait. That is, increases in Baffin Current flow would cause the following responses within Baffin Bay: an eastward shift in the West Greenland Current/Baffin Current boundary at Davis Strait; a deepening of the warm halocline of West Greenland Current waters entering Baffin Bay; an increase in Baffin Bay recirculation below the Davis Strait sill depth; and enhanced diffusion of warm, salty properties to the deep. In contrast, relatively diminished Baffin Current flow would cause the following: a shallower warm halocline for West Greenland Current input; less recirculation below the Davis Strait sill depth; and moderate diffusion of relatively cool, fresh properties to the deep. Oscillation between these responses appears to maintain the intermediate (700--1500 m) structure of waters in the central basin.