Investigating the typicality of the dynamics leading to extreme temperatures in the IPSL-CM6A-LR model

Understanding the physical mechanisms leading to extremes of quantities of interest in dynamical systems remains a challenge. Under mild hypothesis, the application of the theory of large deviations to dynamical systems predicts the convergence of trajectories leading to extremes towards a typical, i.e. most probable, one called the instanton. In this paper, we use a 2000 years long simulation of the IPSL-CM6A-LR model under a stationary pre-industrial climate to test this prediction. We investigate the convergence properties of trajectories leading to extreme temperatures at four locations in Europe for several variables. We show the convergence of trajectories for most physical variables, with some geographical and temporal discrepancies. Our results are coherent with the most probable path prediction and suggest that the instanton dynamics leading to extremes is a relevant feature of climate models.