Application of a prognostic model TAPM to sea-breeze flows, surface concentrations, and fumigating plumes

We apply The Air Pollution Model (TAPM) (version 2.0), a three-dimensional prognostic model developed as a tool to predict both meteorological and air pollution fields for environmental impact assessments and related air pollution studies, to data from the 1995 Kwinana Coastal Fumigation Study. The field study was conducted over a 12-day summer period in the coastal region of Kwinana in Western Australia in order to investigate the local sea-breeze meteorology, the footprint of SO2 concentration due to industrial sources, and the behaviour of fumigating plumes from power plant stacks. The National Centers for Environmental Prediction meteorological analyses are used as input synoptic fields in the model, multi-level nesting is applied, and the model is run both with and without assimilation of local surface wind measurements. The results show that TAPM simulates the onset of sea breezes, and their magnitude and decay with time, reasonably accurately. As regards to the plume footprint, TAPM performs as well as a specialised regulatory model driven by observed meteorology in Kwinana. As expected, TAPM gives better predictions when the wind data are assimilated, but the results without data assimilation are also good. Comparison with the hourly-averaged dispersion moments (i.e., the mean plume height, standard deviations and skewness values), obtained using a limited number of lidar plume scans both before and after fumigation, demonstrates that TAPM is capable of realistically simulating the observed fumigation characteristics (e.g., negative vertical skewness) and the influence of vertical wind direction shear (i.e., positive lateral skewness)