An overabundance of nitrogen results in a number of harmful environmental conditions (e.g., acidification in coastal waters and reduced biodiversity in forests) that can negatively impact communities. Ammonia, the dominant form of reduced reactive nitrogen, readily deposits from the atmosphere under certain conditions, but exchange rates are highly uncertain and difficult to model over time and distance. ATDD scientists conduct:

  • Chemical processes research: investigate the processes that influence the transfer of reactive nitrogen to aquatic and terrestrial ecosystems, with a focus on measurement of ammonia air-surface exchange in agricultural regions and coastal areas. Results will provide information to improve emission estimates and modeling capabilities on local and regional scales.
  • Integrate chemical measurement studies: develop better ways to integrate measurement studies to include multiple forms of reduced and oxidized reactive nitrogen compounds because the abundance of these compounds and their impact on the environment fluctuates temporally and spatially.
  • Quantify organic and inorganic reactive nitrogen in the environment: examine the development of techniques to quantify organic forms of reactive nitrogen, in addition to refining methods for inorganic nitrogen.
  • Support air quality modeling: work to incorporate inorganic and organic reactive nitrogen data into air quality modeling efforts conducted by ATDD, other NOAA labs, and academic partners.


Farm tractor spraying fertilizer

Farm tractor spraying fertilizer


Interns installing ammonia sensors

Interns installing an automated exchange
mechanism to measure profiles of atmospheric ammonia concentrations over maize
during a growing season at the University of Illinois Urbana-Champaign’s Energy Farm


Dr. Myles preparing a sampling tube

Dr. Myles coating the inside of a sampling tube to
capture basic gases from the atmosphere