Fig. 10

A 2017 time series of vegetation indices a–d, daily mean GPP and shortwave down-welling radiation ‘SW↓’ (d and e, respectively). Vegetation indices are calculated from solar noon scans with an 80° symmetric FOV centred on 0° azimuth. Vegetation indices are coloured by the sky stability indicator. Linear regression R² and slope values use daily observations correlated with daily GPP and are inserted in each subplot. The first row of the R² and slope values use all valid data (n = 326), and the second line uses the filtered data with a sky stability threshold > 30 (n = 109). All p-values < 0.001. Some outliers are outside the y-axis bounds to maintain figure clarity