Fig. 1.

Albedo trend. Area- and energy-weighted average of multimonth (March to September of each year) mean (A) surface albedo over the entire Arctic and (B) planetary albedo over the Arctic oceanic area (north of 60°N). The solid lines are linear least-squares fit to the corresponding time series with the trend (in % decade⁻¹) marked in colors with the 95% confidence interval as uncertainty at the bottom. All trends are statistically significant at the 99% confidence level. In A the black, blue, and green dots are, respectively, CAM5 model results, APP-x, and CLARA-A2 satellite-inferred surface albedo from 1982 to 2014. The correlation coefficient (R) between CAM5 and APP-x results is 0.8 (P < 0.01) and the RMB of the simulation is −1%. The R between CAM5 and CLARA-A2 results is 0.88 (P < 0.01) and the RMB of the simulation is 2%. In B the red and black dots are CERES and CAM5 planetary albedo from 1980 to 2014, respectively. The R between CAM5 and CERES results is 0.85 (P < 0.01) and the RMB of the simulation is −2%.