In rangelands, unlike cultivated fields, soil surface conditions and vegetation cover are far from uniform. Field measurements taken within rangeland environments show that the shape of vertical dust concentration profiles can vary significantly between wind erosion events. Regression fits used to analyze vertical dust concentration profiles are therefore better for some events than others. Such variability has usually been explained as experimental error (or noise) or as a result of the nonuniformity of surface conditions. A computer simulation model (DSism) is used to examine this variability in terms of wind erosion processes. Analysis of these simulation results together with field observations shows that nonuniformity in surface conditions alone cannot explain variations observed in the vertical dust concentration profiles. These same simulations suggest that much of the variability in vertical dust concentration profiles is the result of thermal heating of the soil surface.