Seasonal Variations in Currents and Water Properties in Northwestern Baffin Bay, 1978-1979

Abstract

Year-long records of current speed and direction, temperature and conductivity were obtained from five current meter moorings in northwestern Baffin Bay. Significant seasonal changes in all these parameters were found, which closely followed the seasonal cycle of sea-ice cover. A general winter weakening of the near-surface currents (by a factor of 2 or more) was observed. Deeper currents exhibited a smaller decrease, resulting in a general decrease in baroclinicity during the winter. An exceptional case was observed off the north coast of Bylot Island, where the deep currents reversed. An increase in salinity combined with freezing temperatures was observed in the upper part of the water column during the winter. At some sites this uniform layer appeared to deepen at a steady rate of approximately 40-50 m per month, to a maximum depth between 200 and 250 m. It was not possible, however, to distinguish between the effects of local convection and horizontal advection in deepening the layer.

Key words: current, seasonal variation, temperature, salinity, Arctic, Lancaster Sound, Baffin Bay