A Field Investigation of Dust Devils

Abstract

A field observation program was conducted at El Mirage, Calif., to investigate some aspects of the interaction between dust devils and their environment. The outputs of sensors designed to measure vertical vorticity were recorded, together with those of cup anemometers. Analysis of the data indicates that there is no correlation between the sense of rotation of the vorticity meter and that of dust devils crossing the observing area. Tangential velocity, vertical velocity and temperature were determined in 11 dust devils. Maximum vertical velocities were seen to be much less than tangential velocities, indicating that the boundary layer height extended well above the height of measurement.