AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Creating and Evaluating a New National Inventory for Livestock Ammonia Emissions in the United States
ALYSSA MCQUILLING, Peter Adams, Carnegie Mellon University
Abstract Number: 336 Working Group: Primary and Secondary Aerosols from Agricultural Operations
Abstract As sulfur dioxide and nitrogen oxide emissions have decreased in recent years, the role of ammonia in particulate matter formation has come under greater scrutiny. In order to understand the role of ammonia in PM formation, we must first accurately estimate the amount of ammonia emitted in the United States, paying particular attention to its spatiotemporal distribution. In the United States, livestock account for roughly 70% of all ammonia emissions (UESPA, 2004); thus, capturing the variability in these emissions is critical to accurately modeling their impacts. The seasonal cycle of the emissions is especially important as PM generally is more sensitive to ammonia in colder, winter months. In order to estimate these emissions from major livestock sectors (cattle, swine and poultry) we have developed and evaluated a set of farm emissions models (FEMs), semi-empirical process-based models. A national emissions inventory is developed based on these FEMs, in conjunction with important regionally-specific animal practices data from US Department of Agriculture (USDA), and animal population data from the most recent USDA Agricultural Census, and meteorological inputs from the National Climate Data Center (NCDC). This is the first time that an inventory has been done with process-based modeling underlying all the major livestock sectors. This simulated inventory is being evaluated through its implementation in a chemical transport model to predict gas and particulate ammonia and ammonium concentrations. The model will be run using emissions from the National Emissions Inventory from 2011, version 2 as a base case in CAMx, and our livestock ammonia inventory (from our process-based model) will be used to evaluate the changes observed due to spatiotemporal variability in emission factors related to meteorology and manure management. Additionally, the inventory will be evaluated by comparing predicted concentrations to observations from the National Atmospheric Deposition Program and the Ammonia Monitoring Network.