Ensembles of climate simulations to anticipate worst case heatwaves during the Paris 2024 Olympics

Ensembles de simulations climatiques pour anticiper les pires vagues de chaleur pendant les Jeux Olympiques de Paris en 2024

Pascal Yiou (1, 2) , Camille Cadiou (2) , Davide Faranda (3, 4, 1, 2) , Aglaé Jézéquel (3) , Nemo Malhomme (2) , George Miloshevich (2) , Robin Noyelle (2) , Flavio Pons (2) , Yoann Robin (2) , Mathieu Vrac (2)

1 LSCE - Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette]
2 ESTIMR - Extrèmes : Statistiques, Impacts et Régionalisation
3 LMD - Laboratoire de Météorologie Dynamique (UMR 8539)
4 London Mathematical Laboratory

The Summer Olympic Games in 2024 will take place during the apex of the temperature seasonal cycle in the Paris Area. The mid-latitudes of the Northern hemisphere have witnessed a few intense heatwaves since the 2003 event. Those heatwaves have had environmental and health impacts, which often came as surprises. In this paper, we search for the most extreme heatwaves in Ile-de-France that are physically plausible, under climate change scenarios, for the decades around 2024. We circumvent the sampling limitation by applying a rare event algorithm on CMIP6 data to evaluate the range of such extremes. We find that the 2003 record can be exceeded by more than 4 °C in Ile-de-France before 2050, with a combination of prevailing anticyclonic conditions and cut-off lows. This study intends to raise awareness of those unprecedented events, against which our societies are ill-prepared, in spite of adaptation measures designed from previous events. Those results could be extended to other areas of the world.

Mots clés: Heatwaves; Rare event algorithms

Domaines: Océan, Atmosphère

Pascal Yiou, Camille Cadiou, Davide Faranda, Aglaé Jézéquel, Nemo Malhomme, et al.. Ensembles of climate simulations to anticipate worst case heatwaves during the Paris 2024 Olympics. npj climate and atmospheric science, 2023, 6, pp.188. ⟨10.1038/s41612-023-00500-5⟩. ⟨hal-04283599⟩