Climate & Water Futures | Dynamics and Statistics of Atmospheric Blockings and Persistent Extreme Events: A New Notion of Typicality

The simple fact that we can visually identify blocking events by inspecting a weather map suggests that they correspond to special configurations of the atmospheric flow. Prof. Lucarini will discuss how different lines of evidence point to the fact that blockings are associated with conditions of anomalously high instability of the atmosphere and that they are a clear manifestation of the great dynamical heterogeneity of the atmosphere. Such heterogeneity has important mathematical and practical implications for the study of atmospheric dynamics. Blockings are also often the culprits for persistent climatic extremes like heatwaves or cold spells. Using a methodological framework based on large deviation theory and taking advantage of long simulations by a state-of-the-art Earth system model, he will show how it is possible to introduce a notion of dynamical typicality for heatwaves and cold spells even if such events are rare and stand out with respect to typical atmospheric conditions. This allows for better understanding phenomena like the 2010 Russian Heatwave or the 2021 Western North America summer heatwave and for seeing them as unlikely but possible manifestations of climate variability rather than freak events. A separate powerful data-mining methodology - archetype analysis - confirms the findings above and associated the heatwaves to blocking high pressure systems linked to stalled Rossby wave packets.

About the Presenter
Valerio Lucarini was born in Ancona (Italy) in 1976. He studied physics at Scuola Normale Superiore (Pisa) and at the University of Pisa. He obtained in 2002 a MSc in Climate Physics and Chemistry at MIT and a PhD in Physics at the University of Eastern Finland. He has held academic positions at the University of Bologna, at the University of Hamburg, and at University of Reading, where he founded the Centre for the Mathematics of Planet Earth. Since 2024 he is Professor of Applied Mathematics at the University of Leicester, where he leads the Computational and Mathematical Modelling research group.

Valerio is the recipient of the 2010 Arne Richter Award and of the 2020 L.F. Richardson Medal of the European Geosciences Union, of the 2018 Whitehead Prize of the London Mathematical Society. He has delivered the 2021 Lorenz Lecture at the Annual Meeting of the American Geophysical Union, has received the 2022 SIAM Mathematics of Planet Earth award and the 2024 IUGG Keilis-Borok medal. In 2025 he was elected as a fellow of the American Physical Society. He has held visiting positions in P.R. China, France, Germany, Hungary, and Russia. He is lead author for the chapter of the IPCC AR7 WG1 report dedicated to tipping points. Valerio currently holds editorial roles for Physical Review E and Physical Review Letters. Between 2024 and 2025, Valerio has been the chair of the Topical Group on Physics of Climate of the American Physical Society.

Register for both in-person and virtual participation.