Late Holocene Storminess in the Labrador Sea Region: Exotic Pollen and Aeolian Dust as Indicators of Variability?

The spatial distribution of sea ice in the Arctic is strongly affected by wind stress. Assessing any modern changes in sea ice distribution requires them to be set in the context of natural (background) climate variability over longer time periods than those supplied by instrumental and/or historical records. Palaeo- indicators of regional storm activity are, however, rather rare and although ice cores records can provide continuous, high-altitude, proxy archives of air circulation, ice caps may not be representative of conditions at sea level. The Labrador Sea region is noted for being crucially located with respect to the main track of North Atlantic cyclone systems. Analysis of wind-blown sediments retrieved from fjords both in the southwestern (Placentia Bay, Newfoundland) and in the northeastern (Narsaq Sund, Greenland) Labrador Sea may, therefore, highlight any variability in regional storm activity through time. The wind-blown sediment includes the aeolian dust fraction and long distance (exotic) pollen. The aeolian dust fraction is determined by particle size analysis and end-member modelling and mostly indicative of the windier, winter conditions produced by seasonally steep atmospheric gradients. Variability in past air circulation in spring and early summer is inferred by the concentrations of exotic pollen. Information about storminess variability in South Greenland and Newfoundland regions may contribute to our improved understanding of the interaction between ocean circulation and sea ice distribution and large-scale North Atlantic atmospheric circulation patterns.