title: Bursts in discontinuous Aeolian saltation.
abstract: Close to the onset of Aeolian particle transport through saltation we find in wind tunnel experiments a regime of discontinuous flux characterized by bursts of activity. Scaling laws are observed in the time delay between each burst and in the measurements of the wind fluctuations at the fluid threshold Shields number θc. The time delay between each burst decreases on average with the increase of the Shields number until sand flux becomes continuous. A numerical model for saltation including the wind-entrainment from the turbulent fluctuations can reproduce these observations and gives insight about their origin. We present here also for the first time measurements showing that with feeding it becomes possible to sustain discontinuous flux even below the fluid threshold.
authors.affiliation: Computational Physics, IfB, ETH Zürich, Wolfgang-Pauli-Strasse 27, 8093 Zürich, Switzerland.
authors.forename: M V
authors.initials: MV
authors.lastname: Carneiro
authors.affiliation: Department of Geoscience, Aarhus University, Hoegh Guldbergsgade 2, 8000 Aarhus C, Denmark.
authors.forename: K R
authors.initials: KR
authors.lastname: Rasmussen
authors.affiliation: 1] Computational Physics, IfB, ETH Zürich, Wolfgang-Pauli-Strasse 27, 8093 Zürich, Switzerland [2] Departamento de Física, Universidade Federal do Ceará, 60451-970 Fortaleza, Ceará, Brazil.
authors.forename: H J
authors.initials: HJ
authors.lastname: Herrmann