Ice Movement through Smith Sound in Northern Baffin Bay, Canada, Observed in Satellite Imagery

Abstract

ABSTRACT. Movement of pack ice in Smith Sound in northern Bamn Bay was observed for April 1975 using the satellite imagery obtained by Landsat. Mean velocity was found to be directed to the south with a magnitude of 4 km d -1. The influence of the wind is discussed and the amount of ice transported from Smith Sound ev aluated. The findings show that on a daily average 600 km 2 of pack ice was carried out of the area.

Ocean circulation within the North Water polynya of Baffin Bay

“…Therefore, when an arch blocks the drift of ice from the north, the polynya in Smith Sound will widen, on average, by 20-30 km each day, supplying a southward ice flux of 800-1200 km 2 d -1 across the 40-km width of the drift. This value is comparable to the 600 km 2 d -1 derived directly by Ito and Muller (1982) by satellite tracking of ice over a 10-day period in April 1975. It is sufficiently large to replace all ice in the area of the NOW Polynya study (~20,000 km 2 ) in three weeks.…”

“…The channelling creates persistent wind in Smith Sound with the highest speeds in mid-channel (Ito, 1982). During three consecutive winters (November-March 1974-77) wind on the western side of this atmospheric 'river' averaged 15.6, 24.1 and 14.7 km h -1 from the north-west (Steffen, 1985a).…”

“…At the south-western corner of the NOW Polynya, measurements throughout the winter at a depth of 27 m provided no evidence of warm water . In Smith Sound, Ito (1981) has reported temperature values at a depth of 20 m in April as high as -0.5°C, although the accuracy of these values was not substantiated. Aerial observations by an airborne radiation thermometer have revealed warm patches of approximately 1-km within the NOW Polynya during the winter (Steffen, 1985a, b).…”

“…Satellite-borne sensors provide detailed views of ice in the NOW Polynya relative to surrounding areas (Ito, 1982;Steffen, 1986;Steffen and Lewis, 1988;Le Drew et al, 1992). Although the polynya often has 95% ice cover in January, this ice is mobile and criss-crossed by open leads.…”

Short time‐span ice tracking using sequential AVHRR imagery

“…Satellite-based tracking algorithms have been reported for the past 20 years (Ito and Muller, 1977;Ito and Muller, 1982;Ninnis et al, 1986). Satellite imagery offers numerous advantages over SLAR.…”