Simulation of Terrestrial Dust Devil Patterns

Introducing the surface properties initial vortex, ground temperature and surface momentum impact height (SMIH) for the boundary conditions, dust-devil-scale large eddy simulations (LES) were carried out. Given three parameters of initial vortex, ground temperature and the SMIH based on Sinclair's observation, the dust devil physical characteristics, such as maximum tangential velocity, updraft velocity, pressure drop in the inner core region, and even reverse flow at the top of the core region, are predicted, and are found to be close to the observations, thus demonstrating the ability of the simulation. The physical characteristics of different modeled dust devils are reproduced and compared to the values predicted by Renno et al.' theory. Even for smaller temperature differences or weaker buoyancy, severe dust devils may be formed by strong incipient vortices. It is also indicated that SMIH substantially affects the near-surface shape of terrestrial dust devils.