The objective of this project will be to complete scientific studies to further the state of science for air quality modeling in the United States. To enable scientifically sound decision-making that is protective of public lands, the BLM must analyze current atmospheric air quality conditions and predict impacts of federal actions on air quality as part of the planning and environmental review process. The knowledge provided by these investigations supports informed land management decision making by the Bureau of Land Management (BLM). The studies respond to emerging and complex land management issues, including: (1) air emissions from oil and gas development; (2) development and enhancement of reusable modeling frameworks; (3) smoke emissions and their impact; and (4) improvement of emissions factors for emission sources, including sources of greenhouse gas emissions. These projects supply usable data used to support informed decision making by the BLM and other agencies.