A Theoretical Model for Predicting Visibility During Dust Events

A physically based framework is developed to predict horizontal visibility during dust events by linking surface wind erosion, dust emission, near-surface dust concentration, and visibility. An analytical concentration–visibility relationship is derived using a heuristic closure condition. Dust concentration is further related to wind forcing through saltation-controlled dust emission and steady-state mass conservation, while a moment-balance entrainment model incorporates median particle size and soil cohesion into the threshold friction velocity. The concentration–visibility relationship is evaluated using observations from three published studies and captures the overall variation in the combined dataset with R2 = 0.62. Under the same calibration conditions, the proposed relationship achieved the highest R2 among all formulations examined, indicating that its functional form more effectively captures the nonlinear dependence of visibility on dust concentration in the combined dataset. By linking surface erodibility and aerodynamic forcing to atmospheric dust loading and visibility, the framework provides a physically based approach for dust-event visibility prediction. Further evaluation of the complete model chain requires synchronized observations of surface properties, particle entrainment, dust emission, concentration, and visibility.