In the HSR, the long-term averages for the onset of surface melt
ranged from 11 May (DoY 130) to 5 July (DoY 185), with an overall
average of 19 June (DoY 169) or about half a month later than for the
NEP (Fig. 8). The largest difference between NEP and HSR occurred in
the Barents sector, with a spatially averaged deviation of 49 days. The
long-term trend in the onset of surface ice melting in the HSR averaged
−0.38 days per year from1979 to 2011.Most test points (82%) showed
a negative trend, but 78% of them were insignificant at the 0.05 level