The CAFE Logo
The steam ‘butterfly’ above the coffee cup represents the Lorenz attractor, which has become a symbol for chaos in the weather and climate system. The butterfly depicts the regime nature of weather and climate, which can sit in one regime (represented by the butterfly wing) for some time and then transition to another regime (the other wing).
Ensemble forecasting uses insights from studies of chaotic systems, like the Lorenz attractor, to underpin probabilistic prediction experiments whereby a series of forecasts, with slight scaled differences in their initial conditions are specifically constructed to identify and characterise error growth i.e. predictability in those parts of the climate system one is interest in forecasting.