The NCAR Eulerian Regional Acid Deposition Model

First-generation submodels of gas phase chemistry and aqueous phase chemistry with simple parameterizations of subgrid-scale cloud processing and dry deposition have been completed. Whenever possible, these submodels have been evaluated with or compared to available experimental data and found to be performing well. The submodels have been integrated into a first-generation Eulerian long-range transport and acid deposition model.

A first run with the full modeling system using one set of Oxidant-Scavenging Characteristics of April Rains (OSCAR) data has been completed. The full set of OSCAR data is being analyzed in preparation for model evaluations. We have completed two exhaustive studies on the possible chemical reactions and aqueous phase reactions and evaluated the available data for reaction rate coefficients.

We have also developed an analysis technique for studying source-receptor relationships within the Eulerian modeling framework. These studies and others are covered in this report.