Climatic analysis of sea-ice variability in the Canadian Arctic from operational charts, 1980-2004

We present a complete climatic analysis of sea-ice conditions in the Canadian Arctic based on digitized operational charts from the Canadian Ice Service for the period 1980-2004. The seasonal climatology, spatial variance and linear trends in total ice concentrations (CT) were calculated. The maximum reduction rate in CT was found in the Beaufort Sea (> 24% decade(-1)) and in the Davis Strait/ Labrador Sea region (> 18% decade(-1)) during spring and summer. Empirical orthogonal function (EOF) analysis performed on monthly CT deviations yielded four significant EOF modes explaining 32% of the total variance. The spatial pattern, temporal behaviour and seasonality of these four EOF modes are discussed and correlated with fields of sea-level pressure, surface winds, surface air temperature and sea-surface temperature monthly anomalies. These results point to the dominant influence of the North Atlantic Oscillation on CT decadal anomalies during the cold season, while climate variability in the Pacific influences CT variations in the Beaufort Sea region during spring-summer.