Development of an Interface for the Emissions and Dispersion Modeling System (EDMS) with the SMOKE Modeling System

Currently, within the National Emissions Inventory (NEI), airport, including aircraft, emissions are estimated at the county level as area sources and are represented only in the surface layer of air quality models. In reality, however, aircraft release their emissions both on the surface and while airborne. Therefore, in order to provide a realistic representation of all emissions from aircraft sources, we have developed an interface, called EDMS2Inv, in the Sparse Matrix Operator Kernel Emissions (SMOKE) emission modeling system, that enables processing of emissions inventories from the Federal Aviation Administration (FAA)’s Emissions and Dispersion Modeling System (EDMS) to create emissions inputs to the Community Multiscale Air Quality (CMAQ) modeling system. A research version of EDMS was developed for this project to support the hourly, spatially-allocated, estimation of direct emissions for the criteria air pollutants (CAPs) (i.e., volatile organic compounds, CO, NOx, SOx, particulate matter of size less than 2.5 microns (PM2.5) emitted by commercial aviation from the ground level up to 10,000 ft. EDMS provides a spatially and temporally allocated emissions inventory in an AERMOD-ready format. These emissions, when processed through the new EDMS2Inv interface in SMOKE, allow for an enhanced representation of hourly emissions from aviation sources, specifically in the layers aloft, to more accurately account for emissions from aircraft during takeoff and landing. In this study, we present case studies using EDMS2Inv with hourly EDMS outputs for modeling criteria air pollutants from commercial aircraft operations from three U.S. airports: Atlanta Hartsfield, Chicago O’Hare, and Providence T.F. Green. The EDMS2Inv interface is being used to process emissions from these airports for a nested CMAQ application over the Eastern United States. The improved representation of aviation emissions in all layers of the model facilitates developing new sensitivity scenarios that can subsequently be used to assess the impacts of the rapid growth of aviation in the United States on localto-regional air quality and public health. BACKGROUND AND MOTIVATION About 150 airports in the United States are located in nonattainment areas for one or more criteria. Areas that are designated as nonattainment are mandated to develop State Implementation Plans (SIPs) that identify specific emissions control measures that, when implemented in the future, will improve air quality and thus bring the area into attainment. Current estimates of aircraft emissions that affect local air quality indicate that these emissions are relatively small when compared to emissions from other sources and are small contributors to the overall atmospheric budget of air pollutants. However, it is estimated that passenger-miles traveled in the U.S. will be double or triple the 2006 levels within the next two decades. It is thus imperative that we accurately understand, evaluate, and quantify the relative contribution of aviation emissions to ambient air quality.