ACINN Graduate Seminar - WS 2025/26

2026-01-14 at 12:00 (on-line and on-site) in the seminar room

Heat, Dust, and Thunderstorms: Co-Occurrence of Atmospheric Deserts and Extreme Weather over Europe

Fiona Fix-Hewitt

ACINN, University of Innsbruck

 

Heat waves, Saharan dust outbreaks, and severe convective storms are high-impact weather hazards with consequences for health, infrastructure, ecosystems, and economies. Although they are often treated separately, these phenomena may be connected through “atmospheric deserts” (ADs): air masses formed within the hot, deep, and dry convective boundary layers of arid regions. These air masses can traverse thousands of kilometres  while  reserving their thermodynamic properties which can modulate downstream weather. 

Our analysis shows that while ADs frequently form lids in some regions, their duration is typically short, limiting their direct contribution to prolonged heat waves. Anyhow, anomalously high temperatures do occur more often in the presence of an AD. Contrary to the assumption the AD imposed lid would inhibit thunderstorm formation, we do not find thunderstorm activity to be much reduced within the AD centre. We do find, however, that thunderstorm activity is indeed elevated close to the AD edges, as was assumed. As expected by definition, episodes of anomalously high aerosol optical depth are closely tied to atmospheric deserts; over continental Europe, up to more than 40% of AD hours coincide with strong dust events. 

Together, these findings demonstrate that atmospheric deserts play an important role in understanding heat, dust, and thunderstorm events. Investigating their influence on extremes offers a pathway to improved conceptual understanding and predictive skill for European high-impact weather

 

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