Seasonal Variations of Sea Ice Extent in the Davis Strait-Labrador Sea Area and Relationships with Synoptic-Scale Atmospheric Circulation

Using published data sources for south-eastern Baffin Island, Ungava Bay and the northern Labrador Sea area, a study of the general patterns of sea ice growth and decay has been made for the years 1964 to 1974. From a comparison of individual years an "early" and a "late" pattern of both ice advance and ice retreat are recognised. Mean daily sea-level pressure patterns for June-July and for October-mid-November are examined and a relationship is established between the type of ice advance or retreat pattern and the synoptic circulation over the area. In the years of early ice retreat there is an increased frequency of southerly airflow over the region. Strong winds and the advection of warm air leads to the more rapid removal of the ice compared to years of late ice retreat. Similarly for the years of early ice advance there is an increased frequency of northerly and westerly flow, bringing lower temperatures and an influx of second-year and multi-year ice into the area.