Figure 2
From: Impacts of wind stilling on solar radiation variability in China

Statistical decadal relationship (a–c) between normalized SSR (daily value relative to monthly mean) and U (bins with 0.5 m s−1 width) and (d–f) between R (the relative residual from cloud effects model of the observed SSR to monthly mean) and U for the three individual regions (CE, SC and OT).
Different colors denote the five decades as illustrated at the bottom. The dot-dash lines denote the threshold value of U.