Study of Dust Devils in a Laboratory Experiment

In our paper, we report an alternative idea, how dust devils can be generated and studied in a well-controlled laboratory experiment. We used a large-scale Rayleigh-Bénard experiment with air heated from below and cooled from above to mimic the convective atmospheric boundary layer. We measured the Lagrangian flow field by tracking the flow with helium-filled, and thus, virtually neutrally buoyant soap bubbles. Vortical structures with a vertical updraft and a significant pressure drop in their center have been identified as dust devil-like structures. Generally, they are smaller and weaker in our experiment than real dust devils in their natural environment. Nevertheless, they share many characteristic properties. This pertains e.g. to the lateral migration with the background wind, the arbitrary sense of rotation, or the relation between the size and the lifetime.