Effects of Uncertainties in Meterological Inputs on Urban Airshed Model Predictions and Ozone Control Strategies
Although well recognized within the photochemical modelling community, the effect of uncertainties in meteorological input on model output has not been systematically evaluated. In this study, the urban airshed model (UAM) has been applied to investigate the sensitivity of ozone predictions to the choices in wind fields and mixing height profiles for the data sparse New York Metropolitan area. A set of three wind fields, in combination with spatially varying and spatially invariant mixing heights, was investigated for the July 1988 ozone episode. Model predicted ozone levels were higher under the spatially varying mixing height (SVM) option than under the spatially invariant mixing height (SIM) option. SVM based UAM simulations provided better agreement between the predicted and measured ozone concentrations than SIM based UAM simulations. From the regulatory standpoint, predicted ozone concentrations based on either of these mixing height options were within the range considered as acceptable. UAM simulations with emission reductions of 75% NO(x) and 25% VOC (NO(x) focused) revealed that the improvement in peak ozone levels under the SIM option was larger than that under the SVM option, whereas for the emission reduction scenario of 25% NO(x) and 75% VOC (VOC focused) yields greater improvement in peak ozone under the SVM option with the SIM option. Given the strong influence of mixing heights and wind fields on UAM model predictions in data sparse areas, it is imperative that uncertainties in development of ozone abatement plans be quantified.
Bibliographic Reference: Article: Atmospheric Environment
Record Number: 199610044 / Last updated on: 1996-02-16
Original language: en
Available languages: en