Fig. 1: Global relation between site-averaged NEP and αs.

a Mean (multi-)annual net ecosystem productivity (NEP) versus surface albedo (αs) across all sites. All sites, where our algorithm detected snow at least occasionally, were additionally marked with a white interior. Spearman correlation coefficient is −0.30. Panels b, c show univariate kernel density estimates of the marginal distributions of \({\alpha }_{s}\) and NEP. d Bivariate (2-dimensional) kernel density estimate. e Product of the marginal distributions (expected bivariate kernel density for uncorrelated NEP and αs). f Difference of both.