Vertical profile of the refractive index structure constant for all sites in ERA5 (1979–2019, green) and PRIMAVERA coupled-past (dashed blue line), atmos-past (dash-dotted blue line), coupled-future (red dotted line) and atmos-future (red dash-dot-dotted line) simulations. The higher the, the higher the seeing value. The lines indicate the median, and the spread is represented by the interquartile range (IQR, shading) based on monthly mean data. Results for PRIMAVERA are computed as the model ensemble mean of the monthly-mean median.