A Winter Scientific Reconnaissance of the North Water

Résumé

Since 1966 the Institute's Baffin Bay-North Water Project has been investigating the causes and effects of the large semi-permanent polynya in northern Baffin Bay and Smith Sound. Summaries of existing data have been made by Project personnel and detailed studies have been conducted during the summer season. Winter data in all disciplines relating to the North Water have been conspicuously lacking, so the Project proposed a ship-borne winter scientific reconnaissance of the area. The Canadian Coast Guard Ship Louis S. St. Laurent sailed from Halifax, Nova Scotia, on 1 February 1972, destined for the North Water. A 5-week period was allocated for the cruise. Aboard were: a team of physical oceanographers from the Defence Research Establishment Ottawa; teams representing three of the North Water Project's programs: oceanography, marine biology and meteorology; two ice observers from the Atmospheric Environment Service; and two representatives of the National Film Board. The objectives of the cruise were to collect data relating to the several disciplines represented and gain experience in the operating conditions in anticipation of increased year-round commerce in the eastern Arctic. ... [Because of adverse ice and weather conditions and time constraints] the St. Laurent turned south at 72°06'N, 63°55'W. ... Following the decision to turn south, the scientific party decided that the optimum program would consist of 5 oceanographic stations at 100-mile (160 km) intervals down the centre of Baffin Bay, and 4 stations along the latitude of Godthaab (64°), profiling the West Greenland current. The first station was begun at 10/1900Z at 71°57'N, 62°07'W in 2,000 m of water. Oceanographic samples were taken at 10-metre intervals down to 300 m and at standard depths to the bottom. Biological samples were taken throughout the water column and micrometeorological measurements made. Progress during the next 3 days was so slow that the second station was begun at 13/2400Z at 70°37'N, 56°52'W in 395 m of water. All 3 programs collected data. It had been impractical to remain in the centre of the Bay because of the ice conditions and additional stations over the West Greenland shelf were not warranted. Consequently, the ship proceeded south, in progressively slackening conditions, and took 4 stations along the 64th parallel on the 16th. The ship arrived in Halifax on the morning of the 21st, having logged 4200 miles (6750 km) and consumed 80 per cent of its fuel. The scientific party did not reach the North Water, but did obtain the first winter data from central Baffin Bay. Evaluation of the scientific returns of the trip is now under-way; however, the biologists found what appear to be some unusual specimens at the northern station, while the STD [salinity, temperature, depth] revealed a 6°C thermocline between 100 and 125 m in the West Greenland current. It was also shown that it is possible to collect oceanographic specimens at -30°F (-34°C) with a 20-knot wind (windchill equivalent of no wind and below -70°F, i.e. -57°C) although it was extremely uncomfortable for those who had to work in exposed areas. ...