Search

Dust devils are vertically oriented, columnar vortices that form within the atmospheric convective boundary layer (CBL) of dry regions. They are able to lift a sufficient amount of soil particles including dust to become visible and are considered as a potentially important dust source for the atmosphere. Mineral dust, a key component of atmospheric aerosols, influences the climate by affecting the radiation budget and cloud formation. Current estimates of the contribution of dust devils to the global, regional, and local dust release vary considerably from less than 1% to more than 50%. To address this uncertainty, we perform the highest resolved large‐eddy simulation (LES) study on dust emission in the CBL to date, using the PALM model system and the saltation‐based Air Force Weather Agency (AFWA) dust emission scheme. Our results show that under desert‐like conditions, dust devils are responsible for an average of 5% of regional dust emissions, with temporary maxima of up to 15%. This contrasts with previous measurement‐based (>35%) and LES‐based estimates (∼0.1%). Local emissions of dust devils (up to 10 mg m−2 s−1) are 1–3 orders of magnitude higher than the emission in the surroundings. This makes dust devils important for air quality and visibility. Additionally, our study reveals previously unknown large‐scale convective dust emission patterns. These patterns are tied to the CBL's cellular flow structure and are the main cause of dust release. Contrary to other studies, our findings clarify the important role of saltation‐induced dust emission. Plain Language Summary: Dust devils, vertically oriented convective vortices frequently observed in arid and semi‐arid regions, are potential contributors to the atmospheric dust. This airborne dust has significant implications for climate, as it can alter the radiation budget and influence cloud formation. The exact proportion of atmospheric dust originating from dust devils is currently under debate, with widely varying estimates. To address this uncertainty, we used an advanced turbulence‐resolving large‐eddy simulation model, the PALM model system, combined with the saltation‐based Air Force Weather Agency's dust emission scheme. Our results showed that under desert‐like conditions, dust devils account for an average of 5% of regional dust emissions. Peaks can reach up to 15%. Notably, these figures challenge both previous measurement and simulation‐based assessments. Additionally, our study found that dust devils produce local dust emission fluxes up to 1–3 orders of magnitude higher than ambient values. This suggests a notable effect on air quality and visibility. Moreover, we identified large‐scale patterns of dust emission linked to the flow structure of the convective boundary layer. These patterns emerge as the primary contributors to the regional dust release. Our study underscored the importance of understanding saltation‐induced dust emission and the role of dust devils in the atmosphere. Key Points: Dust devils cause peak dust emission fluxes of 46.7 mg m−2 s−1, which is 1–2 orders of magnitude larger than previous numerical estimatesDust devils contribute an average of 5% to the total dust emission of the simulated domain, with instantaneous contributions of up to 15%Saltation‐induced dust emission is arranged in large‐scale patterns that are related to the polygonal convection cells of the boundary layer [ABSTRACT FROM AUTHOR]