average 8-hour ozone is not applicable because observed data do not exist for grid cells in unmonitored areas. Step 4: The future year gridded 8-hr ozone DVs are calculated by multiplying the gradient-adjusted interpolated 8-hr ozone DVs from Step 2 with the gridded RRFs from Step 3 Step 5: The future-year gridded 8-hr ozone DVs (from Step 4) are examined to determine if there are any peak values higher than those at the monitors, which could potentially cause violations of the applicable 8-hr ozone NAAQS. Annual PM2.5 The unmonitored area analysis for the annual PM2.5 standard will include the following steps: Step 1: At each grid cell, the annual average PM2.5 and by species) will be calculated from the future year simulation, and a gradient in the annual averages between each grid cell and grid cells which contain a monitor will be calculated. Step 2: The annual future year speciated PM2.5 design values will be obtained for each design site as described in section 8.4. For each grid cell, the monitors within its Voronoi Region will be identified, and the speciated PM2.5 values are then interpolated normalized inverse distance squared weightings for all monitors within a grid cell’s Voronoi Region. The interpolated speciated PM2.5 fields are then adjusted based on the appropriate gradients from Step 1. Step 3: The concentration of each of the component PM2.5 species are summed to calculate the total PM2.5 concentration (or DV) for each grid cell. Step 4: The future year gridded annual average PM2.5 estimates are then compared to the annual PM2.5 NAAQS to determine compliance. 24-hour PM2.5 The unmonitored area analysis for the 24-hour PM2.5 standard will include the following steps: Step 1: At each grid cell, the quarterly average of the top 10% of the modeled days for 24-hour PM2.5 (total and by species for the same top 10% of days) will
average 8-hour ozone is not applicable because observed data do not exist for grid cells in unmonitored areas. Step 4: The future year gridded 8-hr ozone DVs are calculated by multiplying the gradient-adjusted interpolated 8-hr ozone DVs from Step 2 with the gridded RRFs from Step 3 Step 5: The future-year gridded 8-hr ozone DVs (from Step 4) are examined to determine if there are any peak values higher than those at the monitors, which could potentially cause violations of the applicable 8-hr ozone NAAQS. Annual PM2.5 The unmonitored area analysis for the annual PM2.5 standard will include the following steps: Step 1: At each grid cell, the annual average PM2.5 and by species) will be calculated from the future year simulation, and a gradient in the annual averages between each grid cell and grid cells which contain a monitor will be calculated. Step 2: The annual future year speciated PM2.5 design values will be obtained for each design site as described in section 8.4. For each grid cell, the monitors within its Voronoi Region will be identified, and the speciated PM2.5 values are then interpolated normalized inverse distance squared weightings for all monitors within a grid cell’s Voronoi Region. The interpolated speciated PM2.5 fields are then adjusted based on the appropriate gradients from Step 1. Step 3: The concentration of each of the component PM2.5 species are summed to calculate the total PM2.5 concentration (or DV) for each grid cell. Step 4: The future year gridded annual average PM2.5 estimates are then compared to the annual PM2.5 NAAQS to determine compliance. 24-hour PM2.5 The unmonitored area analysis for the 24-hour PM2.5 standard will include the following steps: Step 1: At each grid cell, the quarterly average of the top 10% of the modeled days for 24-hour PM2.5 (total and by species for the same top 10% of days) will
App-H-Photochemical-Modeling-Protocol.docx