Preparation of the First National Emissions Inventory for Modeling at a national level in Mexico

The first Mexico’s National Emissions Inventory (MNEI), was developed for base year 1999 and includes emission estimates for seven pollutants (VOC, CO, NOx, SO2, PM10, PM2.5, and NH3) for point, area, on-road mobile, nonroad and natural sources. These emission estimates are available for each one of the 2,443 municipalities of Mexico. The MNEI represents a significant effort of diverse public and private entities in México, U.S. and Canada. The data and report of the first national emissions inventory for México were published in September, 2006 and are now available for use in air quality modeling. This paper focuses on the progress to date in the development of the first MNEI for air quality modeling at a national level with the Comprehensive Air Quality Model with Extensions (CAMx) modeling system. The information of point, area, on-road mobile, nonroad and natural sources are temporally and spatially allocated with the Sparse Matrix Operator Kernel Emissions (SMOKE) modeling system for a modeling domain over the whole country with a grid cell resolution of 24 km. This paper emphasizes the main considerations, assumptions and limitations to develop the spatial emission allocation. This work represents the first attempt to develop an emission inventory for modeling at national level in Mexico and its objective is to promote the use of the NEI for modeling at INE and in other institutions. Hence, there are several areas of opportunity to enhance the results, basically by improving the assumptions used in this work