Talk by Jeroen Wouters

(Postdoc, Centre for Ice and Climate)

Title: “Sampling extreme heat waves using a rare event algorithm”

Abstract: Studying extreme events and how they evolve in a changing climate is a major scientific challenge. Starting from complex climate models, a key difficulty is to be able to run long enough simulations to observe those extremely rare events. In physics, chemistry, and biology, rare event algorithms have recently been developed to compute probabilities of events that cannot be observed in direct numerical simulations. Here we apply such an algorithm to the sampling of extreme heat waves. This approach gives an improvement of more than two orders of magnitude in the sampling efficiency. We describe the dynamics of events that would not be observed otherwise. We show that European extreme heat waves are related to a global teleconnection pattern involving North America and Asia. This tool opens up a wide range of possible studies to quantitatively assess the impact of climate change.
This is joint work with Francesco Ragone and Freddy Bouchet.