Soutenance
Linh Nhat LUU (LSCE)
Date et heure : Le 26-06-2020 à 15h00
Type : thèse
Université qui délivre le diplôme : UVSQ - Université Paris Saclay
Lieu : Thèse en ligne - https://eu.bbcollab.com/guest/45e8c53c65f34ee99960114fd046e577
Dr. Peter Stott - Professor, University of Exeter, UK - Reviewer
Dr. Erika Coppola - Senior scientist, ICTP, Italy - Reviewer
Dr. Matthieu Roy-Barman - Professor, Université Paris-Saclay, France - Examiner
Dr. Aurélien Ribes - Chargé de recherche, Méteo France, France - Examiner
Dr. Robert Vautard - Directeur de recherche, LSCE/IPSL, France - Supervisor
Dr. Pascal Yiou - Directeur de recherche, LSCE/IPSL, France - Co-Supervisor
The France-Mediterranean area is frequently exposed to heavy precipitation events in the autumn whose daily accumulation can sometimes exceed 300 millimeters. There are a few studies showing the increasing trend in the frequency and intensity of these events (e.g. Vautard et al., 2015; Ribes et al., 2019). However, a formal extreme event attribution that links those changes to human-induced climate change for this area has never been done. This PhD subject aims at quantifying the role of human-induced climate change in altering the statistical properties of extreme convective precipitation event occurring over the France-Mediterranean focusing on the Cevennes mountain range and using a high-resolution model approach including convection-permitting model for the first time. I first analyze the EURO-CORDEX ensemble, which includes different combinations of global climate models and regional climate models. Then I conducted a set of numerical simulations with the WRF model at a convection-permitting resolution. I also compared the simulations with observations and high-resolution re-analyses. The results show that regional models can reproduce extreme convective rainfall events with better agreement with observations by increasing their horizontal resolution, especially to convection-permitting resolution (approx. 3 km). By using these simulations, I show that human-induced climate change consistently makes the extreme 3-hourly and daily precipitation events at least 2 times more likely under current climate. The results also suggest the need of using multi-models approach to reduce the uncertainties in this type of impact study.
Thèse en ligne : https://eu.bbcollab.com/guest/45e8c53c65f34ee99960114fd046e577