Time series of open water area in the greater ASP area for the months of November to March starting in 1978 for November and December, and in 1979 for January to March (and ending in 2012 and 2013, respectively). The linear trend for December (297 ± 186 km² yr⁻¹, p < 0.1) is shown for reference (while trends in other months were not significant at the p < 0.1 level).