Relation of dust devil frequency and diameter to atmospheric temperature

This paper presents the results of further analysis of field data obtained on dust devils in the Mojave Desert during 1968. Emphasis was placed on the search for correlations between atmospheric properties and dust devil characteristics, specifically diameter and occurrence frequency. It was found that the temperature lapse rate γ2 in the highly superadiabatic layer from roughly 0.3 to 10 meters above the surface was the basic determinant for both frequency and diameter. As γ2 increases, frequency increases, and larger-diameter dust devils progressively appear. However, for any given diameter range, frequency increases to a maximum and then decreases with further increase in γ2. These results indicate that dust devils are generated in, and their development is initially controlled by, the γ2 layer.