Exploring the interplay between observed warming, atmospheric circulation, and soil-atmosphere feedbacks on heatwaves in a temperate mountain region

Abstract

This study investigates the exceptional heatwaves of 2022 in the Pyrenees, focusing on their physical drivers and environmental influences. The June heatwave was advective in nature, with stronger mountain-induced circulations resulting in heterogeneous temperature anomalies, while the July event had subsiding and weaker atmospheric flow, leading to more uniform temperatures. The interplay of the synoptic circulation with the complex topography or the pre-existing soil moisture deficits played an important role in driving the spatial variability of temperature anomalies in the heatwaves and contributed significantly to their regional amplification. In addition, human-induced climate change has exacerbated these extreme weather phenomena, with more intense heatwaves in the recent period (1986-2021) compared with the past (1950-1985). This research contributes to a more realistic assessment of the impact of climate change on heatwaves in mountain regions.