Typicality of the 2021 Western North America Summer Heatwave

Abstract

Elucidating the statistical properties of extreme meteo-climatic events and capturing the physical processes responsible for their occurrence are key steps for improving our understanding of climate variability and climate change and for better evaluating the associated hazards. It has recently become apparent that large deviation theory is very useful for investigating persistent extreme events, and specifically, for flexibly estimating long return periods and for introducing a notion of dynamical typicality. Using a methodological framework based on large deviation theory and taking advantage of long simulations by a state-of-the-art Earth System Model, we investigate the 2021 North America Heatwave. Indeed, our analysis shows that the 2021 event can be seen as an unlikely but possible manifestation of climate variability, whilst its probability of occurrence is greatly amplified by the ongoing climate change. We also clarify the properties of spatial coherence of the 2021 heatwave and elucidate the role played by the Rocky Mountains in modulating hot, dry, and persistent extreme events in the Western Pacific region of North America.

arXiv comment11 pages, 4 figures plus supplementary material

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Cited by in corpus (4)

• Saddle avoidance of noise-induced transitions in multiscale systems
• Agnostic detection of large-scale weather patterns in the northern hemisphere: from blockings to teleconnections
• The Typicality of Regimes Associated with Northern Hemisphere Heatwaves
• Constructing Extreme Heatwave Storylines with Differentiable Climate Models