Image caption
An ENSO index that characterizes variability in the 60 years before 1960 (green) and the 60 years after 1960 (purple) for several models, each with a very large ensemble (about 40 on average) of simulations (footnote #3). The y-axis shows the standard deviation of the index. The mean across the multimodel large ensemble averages is designated LE MMEM and the multimodel ensemble average across all Coupled Model Intercomparison Project 6 (CMIP6) models is designated as CMIP6 MMEM. See paper for details.