Fig. 5. Performance of random forest parameterization when excluding latitude bands during the training process.

a–c Offline performance at x8 as measured by R² of the tendency of q_T (including all longitudes and levels) versus latitude, and d–f online performance as shown by the zonal- and time-mean precipitation for the x8-RF simulation. Results are shown in black dash-dotted for cases in which the training process excludes in both hemispheres the latitude bands a, d 5.1^∘–15.5^∘, b, e 34.5^∘–44.9^∘, and c, f 60.5^∘–70.8^∘. Gray bars indicate latitude bands that where excluded during the training. For comparison the results for x8-RF without any latitudes excluded in training are plotted in orange.