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. 2017 Feb 2;5:e2957. doi: 10.7717/peerj.2957

Figure 1. (A) Annual winter (December to February) North Atlantic Oscillation index (NAO), Arctic Oscillation (AO), and El Nino-Southern Oscillation (ENSO), 1971–2014.

Figure 1

Note red arrows indicate possible regime shifts (1977, 1989, 1989/99, 2010) and black arrows possible years with poor ringed seal condition: 1973/74, 1983, 1992, 1998, 2010 (Smith & Stirling, 1978; Hare & Mantua, 2000; Smith & Harwood, 2001; Benson & Trites, 2002; Ferguson, Stirling & McLoughlin, 2005; Litzow, 2006). (B) Sea ice patterns over the day of the year showing inter-annual variation in timing of spring breakup, duration of open water season, and time of freeze-up, 2003–2013. Note that autumn 2010 freeze-up did not occur until January 2011.