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The Qatar Air Quality Modelling System (QAQM) was developed by Qatar Petroleum (QP) and Total Research Centre - Qatar (TRC-Q) to elucidate the causes of the high ozone levels in Qatar's lower atmosphere. Ozone formation is a complex phenomenon involving primary pollutants (nitrogen oxides and volatile organic compounds), solar radiation and local meteorological conditions. The pollutant's long lifetimes underpin the need to consider their impact at regional, as well as local, scales. Meteorological simulations are obtained using well-known MM5 software. Using nested grids, simulations are first run at a large scale with coarse resolution and then refined over the Gulf and Qatar scales in successive iterations. This approach takes into account trans-boundary dispersion of pollutants along the Gulf, as well as local phenomena with a higher resolution (sea-breeze, local turbulence, etc.). A comprehensive emission inventory of ozone precursors has also been constructed at the regional and local scales. Various methodologies have been employed covering all activity sectors and scales (direct knowledge of industrial processes, statistical data combined with emission factors and road traffic emissions models). This emission inventory coupled with Geographical Information Systems produces a geo-referenced database of primary pollutants which serves as an input for the modelling platform. The CHIMERE photochemical model uses the dispersion and emission inventory previously generated as inputs, and then simulates the chemical reactions between pollutants at all steps, in space and time. The outputs from the model simulations were validated against meteorology and air quality data collected from various monitoring stations in Qatar. They showed a global acceptable agreement. This study has also improved the scientific knowledge on processes involved in the ozone cycle in the Gulf region. The QP QAQM platform can be used as a planning tool to assess the environmental impact of new industrial activities. It is also a suitable basis for further developments in the field of air quality monitoring, forecasts and mitigation. TRC-Q is currently building on this successful experience to develop new technologies as an answer to the environmental challenges resulting from the extraordinary growth currently enjoyed by Qatar. |
