Sensitivity Analysis and Preliminary Evaluation of RELMAP (Regional Lagrangian Model of Air Pollution) Involving Fine and Course Particulate Matter

摘要

In response to the new, size-discriminate federal standards for Inhalable Particulate Matter, the Regional Lagrangian Model of Air Pollution (RELMAP) has been modified to include simple, linear parameterizations. As an initial step in the possible refinement, RELMAP has been subjected to a sensitivity analysis in which the effect of inducing a +/- 50% change in the three major parameterizations (transformation rate and wet and dry deposition rates) involving the simulation of fine and coarse particulate matter has been examined. Simulated concentrations of fine and coarse particulate matter proved to be most sensitive to the wet deposition of fine and coarse particulate matter, respectively; fine concentrations were somewhat sensitive to the transformation rate of sulfur dioxide SO2 into sulfate SO4=, and less sensitive to the wet deposition of SO2, and the dry deposition of fine particulate matter and SO2; and finally, coarse concentrations were somewhat sensitive to dry deposition of coarse particulate matter. In order to assess the model's abilities, and to determine just how accurately these new parameters simulate the actual physical and chemical processes of the atmosphere, RELMAP was evaluated for the summer of 1980 using emissions data from the NAPAP Version 5.0 emissions inventory, monitoring data from the Inhalable Particulate Network, and meteorological data from the National Climatic Data Center. Unfortunately, several obstacles limited the scope of the evaluation, the two most important being the omission of open source emissions from the NAPAP inventory, and the spatial and temporal incompatibility of the IPN data. Given the nature of these deficiencies, it is not surprising the model significantly underpredicted the concentrations of fine and coarse particulate matter. The model did, however, exhibit some skill in its simulation of the concentrations, producing correlation coefficients of 0.53 and 0.33 for fine and coarse particulate matter respectively.