Figure 2. Small scale comparison of model fit with station data from GHCN^14,15 for annual precipitation sums derived from six different models.

Models have been calculated for each station separately, including a minimum of 16 surrounding stations in a 2° search radius. This illustrates how well modelled precipitation corresponds to measured stations at the scale <=2°. The figure shows the mean R² value for 2° grid cells. The upper row additionally illustrates different steps of the CHELSA algorithm, with ERA-Interim¹⁷ performing worse than GPCC⁵⁰, and CHELSA showing the highest fit after including orographic effects.