Figure S3 Ensemble mean and standard deviation of the SI-x leaf index and departure of each model and observations from the ensemble mean. Panels (1) and (2): mean (1) and standard deviation (2) of spring onset timing as indicated by SI-x leaf across the first member of the 26 CMIP6 models during 1981-2014 in the historical simulations. Panels (3-28): differences between each model 1981-2014 mean SI-x leaf and the ensemble mean. Panels (29-30): differences between the two observation-based mean first leaf and the model ensemble mean.