What physical insights can we learn from rare events simulation with climate models?

Robin Noyelle

The study of the statistical and dynamical characteristics of extreme and very extreme events in the climate system is impaired by a strong under-sampling issue. Because extreme events are rare, answering questions about the physical mechanisms from which they arise usually depends on the investigation of just a few cases, either in observations or in models. Rare events algorithms are a solution proposed recently to simulate more extremes than what the models would spontaneously do. In this talk I will show how we can use these techniques to estimate more precisely the return times of such extremes and what kind of physicaly insights can be learned from them. I will illustrate these results using simulations of extremely hot and dry summers in Europe in both the IPSL and the CESM2 climate models.