Nitrogen Deposition and Nutrient Modeling

EPA researchers are using the Community Multiscale Air Quality (CMAQ) modeling system to understand the life cycle of nitrogen from its release into the atmosphere to its deposition on land and water. Using this model, researchers can develop deposition scenarios and compile information on nitrogen movement that can be used to manage nitrogen use and impacts.

In addition to CMAQ, EPA is improving its knowledge of the total amount of reactive nitrogen in the air and how it is deposited onto land and water. Research in this area is supporting rule making for the National Ambient Air Quality Standards and will include the following: 

  • Improve ways to measure the transfer of nitrogen and other pollutants from the atmosphere to land and water surfaces.
  • Use computer modeling to study deposition sources, atmospheric concentrations and their distribution patterns to urban areas, determine model efficiency, and appraise low-cost deposition techniques.
  • Measure gaseous and particulate nitrogen mixtures at five existing air quality monitoring network sites to describe the total amount of atmospheric nitrogen.
  • Study the relationships between airborne concentrations and total deposition of nitrogen and sulfur.

Additional research is underway to develop water quality simulation modeling tools for managing nitrogen and phosphorus pollution. Tools like this will be part of a larger decision support system intended to help water resource managers protect waters from nutrient pollution.