ARL News

Multi-agency Study of Ammonia at Beltsville


August 1, 2005

Four groups are collaborating on a study of ammonia in air, at Beltsville, MD, in rural countryside just outside Washington, DC. Two ARL groups are involved – Silver Spring and Oak Ridge – together with Howard University and the EPA. The intent is to evaluate the performance of new ammonia detectors now planned for deployment in the EPA dry deposition program (CASTNet – the Clean Air Status and Trends Network). The ARL participation is a contribution to the NOAA Air Quality Program.

Estimation of dry deposition rates of ammonia has been hindered by the lack of instrumentation capable of giving reliable answers, routinely, on an hour-by-hour basis. There have been several recent developments that show promise. One of these, a development by ECN in the Netherlands, has been selected for field testing by the EPA. The Beltsville study now under way is the first step in the evaluation process. ARL’s deposition monitoring program has been addressing the issue of ammonia deposition for a number of years, and the skills developed are now being exercised in support of the national routine CASTNet program.

The opportunity is being taken to look at several additional chemical species, as well – nitric acid vapor, sulfur dioxide, particulate ammonium, nitrate and sulfate.

Contact information: Winston T. Luke
Phone: (301) 713-0971