Emission Inventory Data Used in 2006 Air Quality Forecasting

The following updates have been made to the emission inputs:

(1) For point sources, 2004 Continuous Emission Monitoring (CEM) data were used to generate a base year of emission estimates for NOx and SO2. For other pollutants and non-Electric Generating Units, base year 2001 emissions were used. Using the Annual Energy Outlook (AEO) from the Department of Energy, the Electric Generating Unit (EGU) emissions to the year 2006 using the ratios of 2006 to 2004 computed from the AEO were projected on a regional basis. The only exception was for California, where 2004 emissions of NOx and SO2 were held constant for 2006. The AEO for California erroneously projects emissions to increase by a factor of 8 between 2004 and 2006. Additionally, monthly temporal profiles were created on a state-by-state basis using the 2004 CEM data for the EGU emissions. These profiles will be applied for the 2006 ozone forecast season. In addition, the 2001 non-EGU emissions for Georgia with base 2002 emissions as supplied by the Georgia Department of Natural Resources were replaced.

(2) For area and non-road sources, the year-specific 2001 fire inventory, used in previous years was replaced with an average fire-year inventory based on the years (1996-2002). All other area source emissions will continue to use base 2001 year emissions.

(3) For mobile source emissions, projected Vehicle Miles Traveled (VMT) data to 2006 along with an updated 2006 fleet as input into EPA’s Mobile6 model were used. Similar to last year’s approach, a non-linear regression model using 2001 temperature data was developed. These new regression factors are then used in the Air Quality Forecast system to modulate the mobile source emissions based on the forecast temperature from the meteorology model. For 13 counties in the Metropolitan Atlanta Area, VMT data from a 2005 run of a travel demand model and Mobile6 inputs from the Georgia Department of Natural Resources replaced the default values.

(4) For biogenic sources, all inputs used in the forecast system were updated to the Biogenic Emission Inventory System (BEIS) version 3.13.