Distribution of the 0.55–2.5 μm spectral slope vs. that of 0.45–0.55 μm spectral slope for the global observations. These observations were acquired at EQ3 (top) and EQ4 (bottom) at phase angles of ~8° and 30°, respectively, showing the common increase of the two spectral slopes with phase angle, while remaining strongly anticorrelated with one another. A similar correlation between the two slopes is observed for the other datasets.