Temperature extremes in Europe: mechanisms and responses to climate change.

• Main Author: Cattiaux, Julien
• Other Authors: Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Groupe d'étude de l'atmosphère météorologique (CNRM-GAME), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris VI, Robert Vautard
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2010
• Subjects: extrêmes de température; dynamique du climat; changement climatique; [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology; Spate; North Atlantic
• Online Access: https://tel.archives-ouvertes.fr/tel-00561972; https://tel.archives-ouvertes.fr/tel-00561972/document; https://tel.archives-ouvertes.fr/tel-00561972/file/ms.pdf

Europe witnessed a spate of record-breaking warm seasons during the 2000s, inducing particularly strong societal and environmental impacts. This thesis aims to contribute to the understanding of physical mechanisms responsible for such extremes, in order to anticipate their responses to future climate change. Involved processes are assessed by both statistical data-analysis of observations and climate projections and regional modeling experiments. First we show that while the inter-annual European temperature variability appears driven by disturbances in the North-Atlantic dynamics, the recent warming is likely to be dissociated with potential circulation changes. This inconsistency climaxes during the exceptionally mild autumn of 2006. Recent warm surface conditions in the North-Atlantic ocean seem to substantially contribute to the European warming in autumn--winter, while more local processes appear predominant in spring--summer (e.g., influence of soil moisture). Then multi-model analysis, based on climate projections of the International Panel on Climate Change, show that the inconsistency noticed over recent decades is likely to continue in future years. In particular, it appears that climate change does not affect the internal variability of the North-Atlantic dynamics in a significant manner. Thus future temperature extremes should be associated with circulations similar to those observed during recent episodes. In this context the European winter of 2009/10 can be considered as a cold extreme in a warming climate. Le climat des années 2000 a été marqué en Europe par une vague d'épisodes chauds battant tous les précédents records saisonniers de température et s'accompagnant d'impacts sociétaux et environnementaux particulièrement sévères. Cette thèse se propose de contribuer à la compréhension des mécanismes physiques responsables de tels extrêmes, dans le but d'anticiper leurs réponses au changement climatique futur. Ce travail mêle ainsi analyses statistiques de données d'observations et de ...