The box model and the acoustic sounder, a case study

Concentrations of SO2 in a large city during a subsidence situation are predicted as a function of time by means of a simple box model and the predictions are compared to actual SO2 concentration measurements. The agreement between model results and measurements is found to be excellent. The model uses the height of the mixing layer as measured by means of an acoustic sounder. It is demonstrated that this height is a dominant factor in determining the variation of the SO2 concentration.