Seasonal Variations in Currents and Water Properties

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 w...

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Bibliographic Details
Main Authors: In Northwestern Baffin Bay, D. D. Lemon, D. B. Fissel
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
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Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.573.4083
http://pubs.aina.ucalgary.ca/arctic/Arctic35-1-211.pdf
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Summary: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 RÉSUMI~. Cinq compteurs de courants, mouillbs au nord-ouest de la baie de Baffin, ont permis d’obtenir B l’annte longue des relevks de la vitesse et la direction des courants ainsi que de la temperature et de la conductivitb. Des variations saisonnieres significatives, btroitement reliees aux cycles saisonniers du couvert de la glace manne, ont btb observdes pour chacune de ces variables. En hiver, un ralentissement (par un facteur de 2 ou plus) de la vitesse des courants fut observb. Les courants plus profonds ont montre une baisse moins accentde, entraînant tout de meme une baisse gbnerale de la baroclinicite durant l’hiver. Un cas exceptionnel a Btb observe au large de l’île Bylot, oh les courants firent une renverse.